Merge branch 'master' into fix-@html-template-set-innerHTML

pull/7364/head
Simon H 4 years ago committed by GitHub
commit fc2cd96d2c
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GPG Key ID: 4AEE18F83AFDEB23

@ -1,6 +1,6 @@
### Before submitting the PR, please make sure you do the following ### Before submitting the PR, please make sure you do the following
- [ ] It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs - [ ] It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
- [ ] Prefix your PR title with `[feat]`, `[fix]`, `[chore]`, or `[docs]`. - [ ] Prefix your PR title with `feat:`, `fix:`, `chore:`, or `docs:`.
- [ ] This message body should clearly illustrate what problems it solves. - [ ] This message body should clearly illustrate what problems it solves.
- [ ] Ideally, include a test that fails without this PR but passes with it. - [ ] Ideally, include a test that fails without this PR but passes with it.

@ -1,29 +1,86 @@
name: CI name: CI
on: [push, pull_request] on:
push:
branches: [ master ]
pull_request:
permissions:
contents: read # to fetch code (actions/checkout)
jobs: jobs:
Setup:
runs-on: ${{ matrix.os }}
strategy:
matrix:
os: [ubuntu-latest, windows-latest, macOS-latest]
steps:
- uses: actions/checkout@v3
- uses: actions/setup-node@v3
with:
node-version: 18
cache: npm
- run: npm install
env:
SKIP_PREPARE: true
- run: npm run build
env:
PUBLISH: true
- name: Upload build assets
id: upload-artifact
uses: actions/upload-artifact@v3
with:
name: build-assets
path: |
index.*
compiler.*
ssr.*
action/
animate/
easing/
internal/
motion/
store/
transition/
types/
Tests: Tests:
needs: Setup
runs-on: ${{ matrix.os }} runs-on: ${{ matrix.os }}
timeout-minutes: 15 timeout-minutes: 15
strategy: strategy:
matrix: matrix:
node-version: [8, 10, 12, 14, 16] node-version: [8, 10, 12, 14, 16, 18]
os: [ubuntu-latest, windows-latest, macOS-latest] os: [ubuntu-latest, windows-latest, macOS-latest]
steps: steps:
- uses: actions/checkout@v1 - uses: actions/checkout@v3
- uses: actions/setup-node@v2 - uses: actions/setup-node@v3
with: with:
node-version: ${{ matrix.node-version }} node-version: ${{ matrix.node-version }}
cache: npm cache: npm
- name: Download build assets
uses: actions/download-artifact@v3
id: download-artifact
with:
name: build-assets
- name: Get Node version ${{ runner.os }}
run: echo "NODE_VERSION=`node --version`" >> $GITHUB_ENV
if: runner.os != 'Windows'
- name: Get Node version ${{ runner.os }}
run: |
chcp 65001
echo ("NODE_VERSION=$(node --version)") >> $env:GITHUB_ENV
if: runner.os == 'Windows'
- run: npm install --save-dev puppeteer@13
if: ${{ runner.os == 'Linux' && (!startsWith(env.NODE_VERSION, 'v8.') && !startsWith(env.NODE_VERSION, 'v10.')) }}
- run: npm install - run: npm install
- run: npm test env:
SKIP_PREPARE: true
- run: npm run test:integration
env: env:
CI: true CI: true
Lint: Lint:
runs-on: ubuntu-latest runs-on: ubuntu-latest
timeout-minutes: 5 timeout-minutes: 5
steps: steps:
- uses: actions/checkout@v1 - uses: actions/checkout@v3
- uses: actions/setup-node@v2 - uses: actions/setup-node@v3
with: with:
cache: npm cache: npm
- run: 'npm i && npm run lint' - run: 'npm i && npm run lint'
@ -34,8 +91,11 @@ jobs:
matrix: matrix:
os: [ubuntu-latest, windows-latest, macOS-latest] os: [ubuntu-latest, windows-latest, macOS-latest]
steps: steps:
- uses: actions/checkout@v1 - uses: actions/checkout@v3
- uses: actions/setup-node@v2 - uses: actions/setup-node@v3
with: with:
cache: npm cache: npm
- run: 'npm i && npm run test:unit' - run: npm install
env:
SKIP_PREPARE: true
- run: npm run test:unit

@ -7,6 +7,8 @@ on:
paths: paths:
- site/content/** - site/content/**
permissions: {}
jobs: jobs:
release: release:
name: Deploy docs name: Deploy docs
@ -25,4 +27,4 @@ jobs:
repo: 'svelte' repo: 'svelte'
branch: 'master' branch: 'master'
docs_path: 'site/content' docs_path: 'site/content'
token: ${{ steps.github-app.outputs.token }} token: ${{ steps.github-app.outputs.token }}

2
.gitignore vendored

@ -1,6 +1,5 @@
.idea .idea
.DS_Store .DS_Store
.nyc_output
.vscode .vscode
node_modules node_modules
*.map *.map
@ -22,3 +21,4 @@ node_modules
_actual*.* _actual*.*
_output _output
/types /types
.eslintcache

@ -1,7 +1,7 @@
const is_unit_test = process.env.UNIT_TEST;
module.exports = { module.exports = {
file: [ file: is_unit_test ? [] : ['test/test.ts'],
'test/test.ts'
],
require: [ require: [
'sucrase/register' 'sucrase/register'
] ]

@ -0,0 +1,15 @@
module.exports = {
spec: [
'src/**/__test__.ts',
],
require: [
'sucrase/register'
],
recursive: true,
};
// add coverage options when running 'npx c8 mocha'
if (process.env.NODE_V8_COVERAGE) {
module.exports.fullTrace = true;
module.exports.require.push('source-map-support/register');
}

@ -2,14 +2,151 @@
## Unreleased ## Unreleased
* Add a11y warnings:
* `aria-activedescendant-has-tabindex`: elements with `aria-activedescendant` need to have a `tabindex` ([#8172](https://github.com/sveltejs/svelte/pull/8172))
* `role-supports-aria-props`: checks that the (implicit) element role supports the given aria attributes ([#8195](https://github.com/sveltejs/svelte/pull/8195))
* Omit a11y warning on `<video>` tags with `aria-hidden="true"` ([#7874](https://github.com/sveltejs/svelte/issues/7874))
* Omit a11y "no child content" warning on elements with `aria-label` ([#8299](https://github.com/sveltejs/svelte/pull/8299))
* Make `noreferrer` warning less zealous ([#6289](https://github.com/sveltejs/svelte/issues/6289))
* `trusted-types` CSP compatibility for Web Components ([#8134](https://github.com/sveltejs/svelte/issues/8134))
* Add `data-sveltekit-replacestate` and `data-sveltekit-keepfocus` attribute typings ([#8281](https://github.com/sveltejs/svelte/issues/8281))
* Don't throw when calling `unsubscribe` twice ([#8186](https://github.com/sveltejs/svelte/pull/8186))
* Detect unused empty attribute CSS selectors ([#8042](https://github.com/sveltejs/svelte/issues/8042))
* Simpler output for reactive statements if dependencies are all static ([#7942](https://github.com/sveltejs/svelte/pull/7942))
* Flush remaining `afterUpdate` calls before `onDestroy` ([#7476](https://github.com/sveltejs/svelte/issues/7476))
* Check value equality for `input` types `url` and `search` ([#7027](https://github.com/sveltejs/svelte/issues/7027))
* Compute node dimensions directly before crossfading ([#4111](https://github.com/sveltejs/svelte/issues/4111))
* Add `readonly` method to convert `writable` store to readonly ([#6518](https://github.com/sveltejs/svelte/pull/6518))
* Ensure `bind:offsetHeight` updates initially ([#4233](https://github.com/sveltejs/svelte/issues/4233))
* Better handling of `inert` attribute ([#7500](https://github.com/sveltejs/svelte/issues/7500))
* Clear inputs when `bind:group` to `undefined` ([#8214](https://github.com/sveltejs/svelte/issues/8214))
* Ensure nested arrays can change at the same time ([#8282](https://github.com/sveltejs/svelte/issues/8282))
* Reduce use of template literals in SSR output for better performance ([#7539](https://github.com/sveltejs/svelte/pull/7539))
* Allow assigning to property of const while destructuring ([#7964](https://github.com/sveltejs/svelte/issues/7964))
* Don't set selected options if value is unbound or not passed ([#5644](https://github.com/sveltejs/svelte/issues/5644))
* Ensure `<input>` value persists when swapping elements with spread attributes in an `#each` block ([#7578](https://github.com/sveltejs/svelte/issues/7578))
* Select first enabled option by default when initial value is undefined ([#7041](https://github.com/sveltejs/svelte/issues/7041))
* Fix race condition on `svelte:element` with transitions ([#7948](https://github.com/sveltejs/svelte/issues/7948))
* Optimise `<svelte:element>` output code for static tag and static attribute ([#8161](https://github.com/sveltejs/svelte/pull/8161))
## 3.55.1
* Fix `draw` transition with delay showing a dot at the beginning of the path ([#6816](https://github.com/sveltejs/svelte/issues/6816))
* Fix infinity runtime call stack when propagating bindings ([#7032](https://github.com/sveltejs/svelte/issues/7032))
* Fix static `<svelte:element>` optimization in production mode ([#7937](https://github.com/sveltejs/svelte/issues/7937))
* Fix `svelte-ignore` comment breaking named slot ([#8075](https://github.com/sveltejs/svelte/issues/8075))
* Revert change to prevent running init binding unnecessarily ([#8103](https://github.com/sveltejs/svelte/issues/8103))
* Fix adding duplicate event listeners with `<svelte:element on:event>` ([#8129](https://github.com/sveltejs/svelte/issues/8129))
* Improve detection of promises that are also functions ([#8162](https://github.com/sveltejs/svelte/pull/8162))
* Avoid mutating spread component props during SSR ([#8171](https://github.com/sveltejs/svelte/issues/8171))
* Add missing typing for global `part` attribute ([#8181](https://github.com/sveltejs/svelte/issues/8181))
* Add missing `submitter` property to `on:submit` event type
## 3.55.0
* Add `svelte/elements` for HTML/Svelte typings ([#7649](https://github.com/sveltejs/svelte/pull/7649))
## 3.54.0
* Pass `options.direction` argument to custom transition functions ([#3918](https://github.com/sveltejs/svelte/issues/3918))
* Support fallback a11y WAI-ARIA roles ([#8044](https://github.com/sveltejs/svelte/issues/8044))
* Prevent running init binding unnecessarily ([#5689](https://github.com/sveltejs/svelte/issues/5689), [#6298](https://github.com/sveltejs/svelte/issues/6298))
* Allow updating variables from `@const` declared function ([#7843](https://github.com/sveltejs/svelte/issues/7843))
* Do not emit `a11y-no-noninteractive-tabindex` warning if element has a `tabpanel` ([#8025](https://github.com/sveltejs/svelte/pull/8025))
* Fix escaping SSR'd values in `style:` directive ([#8085](https://github.com/sveltejs/svelte/issues/8085))
## 3.53.1
* Fix exception in `rel=` attribute check with dynamic values ([#7994](https://github.com/sveltejs/svelte/issues/7994))
* Do not emit deprecation warnings for `css` compiler options for now ([#8009](https://github.com/sveltejs/svelte/issues/8009))
* Make compiler run in browser again ([#8010](https://github.com/sveltejs/svelte/issues/8010))
* Upgrade `tslib` ([#8013](https://github.com/sveltejs/svelte/issues/8013))
## 3.53.0
* Check whether `parentNode` exists before removing child ([#6037](https://github.com/sveltejs/svelte/issues/6037))
* Upgrade various dependencies, notably `css-tree` to `2.2.1` ([#7572](https://github.com/sveltejs/svelte/pull/7572), [#7982](https://github.com/sveltejs/svelte/pull/7982))
* Extend `css` compiler option with `'external' | 'injected' | 'none'` settings and deprecate old `true | false` values ([#7914](https://github.com/sveltejs/svelte/pull/7914))
## 3.52.0
* Throw compile-time error when attempting to update `const` variable ([#4895](https://github.com/sveltejs/svelte/issues/4895))
* Warn when using `<a target="_blank">` without `rel="noreferrer"` ([#6188](https://github.com/sveltejs/svelte/issues/6188))
* Support `style:foo|important` modifier ([#7365](https://github.com/sveltejs/svelte/issues/7365))
* Fix hydration regression with `{@html}` and components in `<svelte:head>` ([#7941](https://github.com/sveltejs/svelte/pull/7941))
## 3.51.0
* Add a11y warnings:
* `a11y-click-events-have-key-events`: check if click event is accompanied by key events ([#5073](https://github.com/sveltejs/svelte/pull/5073))
* `a11y-no-noninteractive-tabindex`: check for tabindex on non-interactive elements ([#6693](https://github.com/sveltejs/svelte/pull/6693))
* Warn when two-way binding to `{...rest}` object in `{#each}` block ([#6860](https://github.com/sveltejs/svelte/issues/6860))
* Support `--style-props` on `<svelte:component>` ([#7461](https://github.com/sveltejs/svelte/issues/7461))
* Supports nullish values for component event handlers ([#7568](https://github.com/sveltejs/svelte/issues/7568))
* Supports SVG elements with `<svelte:element>`([#7613](https://github.com/sveltejs/svelte/issues/7613))
* Treat `inert` as boolean attribute ([#7785](https://github.com/sveltejs/svelte/pull/7785))
* Support `--style-props` for SVG components ([#7808](https://github.com/sveltejs/svelte/issues/7808))
* Fix false positive dev warnings about unset props when they are bound ([#4457](https://github.com/sveltejs/svelte/issues/4457))
* Fix hydration with `{@html}` and components in `<svelte:head>` ([#4533](https://github.com/sveltejs/svelte/issues/4533), [#6463](https://github.com/sveltejs/svelte/issues/6463), [#7444](https://github.com/sveltejs/svelte/issues/7444))
* Support scoped style for `<svelte:element>` ([#7443](https://github.com/sveltejs/svelte/issues/7443))
* Improve error message for invalid value for `<svelte:component this={...}>` ([#7550](https://github.com/sveltejs/svelte/issues/7550))
* Improve error message when using logic blocks or tags at invalid location ([#7552](https://github.com/sveltejs/svelte/issues/7552))
* Warn instead of throwing error if `<svelte:element>` is a void tag ([#7566](https://github.com/sveltejs/svelte/issues/7566))
* Supports custom elements in `<svelte:element>` ([#7733](https://github.com/sveltejs/svelte/issues/7733))
* Fix calling component unmount if a component is mounted and then immediately unmounted ([#7817](https://github.com/sveltejs/svelte/issues/7817))
* Do not generate `a11y-role-has-required-aria-props` warning when elements match their semantic role ([#7837](https://github.com/sveltejs/svelte/issues/7837))
* Improve performance of custom element data setting in `<svelte:element>` ([#7869](https://github.com/sveltejs/svelte/pull/7869))
## 3.50.1
* Add all global objects and functions as known globals ([#3805](https://github.com/sveltejs/svelte/issues/3805), [#7223](https://github.com/sveltejs/svelte/issues/7223))
* Fix regression with style manager ([#7828](https://github.com/sveltejs/svelte/issues/7828))
## 3.50.0
* Add a11y warnings:
* `a11y-incorrect-aria-attribute-type`: check ARIA state and property values ([#6978](https://github.com/sveltejs/svelte/pull/6978))
* `a11y-no-abstract-role`: check that ARIA roles are non-abstract ([#6241](https://github.com/sveltejs/svelte/pull/6241))
* `a11y-no-interactive-element-to-noninteractive-role`: check for non-interactive roles used on interactive elements ([#5955](https://github.com/sveltejs/svelte/pull/5955))
* `a11y-role-has-required-aria-props`: check that elements with `role` attribute have all required attributes for that role ([#5852](https://github.com/sveltejs/svelte/pull/5852))
* Add `ComponentEvents` convenience type ([#7702](https://github.com/sveltejs/svelte/pull/7702))
* Add `SveltePreprocessor` utility type ([#7742](https://github.com/sveltejs/svelte/pull/7742))
* Enhance action typings ([#7805](https://github.com/sveltejs/svelte/pull/7805))
* Remove empty stylesheets created from transitions ([#4801](https://github.com/sveltejs/svelte/issues/4801), [#7164](https://github.com/sveltejs/svelte/issues/7164))
* Make `a11y-label-has-associated-control` warning check all descendants for input control ([#5528](https://github.com/sveltejs/svelte/issues/5528))
* Only show lowercase component name warnings for non-HTML/SVG elements ([#5712](https://github.com/sveltejs/svelte/issues/5712))
* Disallow invalid CSS selectors starting with a combinator ([#7643](https://github.com/sveltejs/svelte/issues/7643))
* Use `Node.parentNode` instead of `Node.parentElement` for legacy browser support ([#7723](https://github.com/sveltejs/svelte/issues/7723))
* Handle arrow function on `<slot>` inside `<svelte:fragment>` ([#7485](https://github.com/sveltejs/svelte/issues/7485))
* Improve parsing speed when encountering large blocks of whitespace ([#7675](https://github.com/sveltejs/svelte/issues/7675))
* Fix `class:` directive updates in aborted/restarted transitions ([#7764](https://github.com/sveltejs/svelte/issues/7764))
## 3.49.0
* Improve performance of string escaping during SSR ([#5701](https://github.com/sveltejs/svelte/pull/5701))
* Add `ComponentType` and `ComponentProps` convenience types ([#6770](https://github.com/sveltejs/svelte/pull/6770))
* Add support for CSS `@layer` ([#7504](https://github.com/sveltejs/svelte/issues/7504))
* Export `CompileOptions` from `svelte/compiler` ([#7658](https://github.com/sveltejs/svelte/pull/7658))
* Fix DOM-less components not being properly destroyed ([#7488](https://github.com/sveltejs/svelte/issues/7488))
* Fix `class:` directive updates with `<svelte:element>` ([#7521](https://github.com/sveltejs/svelte/issues/7521), [#7571](https://github.com/sveltejs/svelte/issues/7571))
* Harden attribute escaping during SSR ([#7530](https://github.com/sveltejs/svelte/pull/7530))
## 3.48.0
* Allow creating cancelable custom events with `createEventDispatcher` ([#4623](https://github.com/sveltejs/svelte/issues/4623))
* Support `{@const}` tag in `{#if}` blocks [#7241](https://github.com/sveltejs/svelte/issues/7241)
* Return the context object in `setContext` [#7427](https://github.com/sveltejs/svelte/issues/7427) * Return the context object in `setContext` [#7427](https://github.com/sveltejs/svelte/issues/7427)
* Fix `{@const}` tag not working inside Component when there's no `let:` [#7189](https://github.com/sveltejs/svelte/issues/7189) * Allow comments inside `{#each}` blocks when using `animate:` ([#3999](https://github.com/sveltejs/svelte/issues/3999))
* Ignore comments in `{#each}` blocks when containing elements with `animate:` ([#3999](https://github.com/sveltejs/svelte/issues/3999)) * Fix `|local` transitions in `{#key}` blocks ([#5950](https://github.com/sveltejs/svelte/issues/5950))
* Add a third parameter to the returned function of `createEventDispatcher` that allows passing an object of `{ cancelable: true }` to create a cancelable custom event. The returned function when called will also return a boolean depending on whether the event is cancelled ([#7064](https://github.com/sveltejs/svelte/pull/7064)) * Support svg namespace for `{@html}` ([#7002](https://github.com/sveltejs/svelte/issues/7002), [#7450](https://github.com/sveltejs/svelte/issues/7450))
* Fix `{@const}` tag not working inside a component when there's no `let:` [#7189](https://github.com/sveltejs/svelte/issues/7189)
* Remove extraneous leading newline inside `<pre>` and `<textarea>` ([#7264](https://github.com/sveltejs/svelte/issues/7264))
* Fix erroneous setting of `textContent` for `<template>` elements ([#7297](https://github.com/sveltejs/svelte/pull/7297))
* Fix value of `let:` bindings not updating in certain cases ([#7440](https://github.com/sveltejs/svelte/issues/7440)) * Fix value of `let:` bindings not updating in certain cases ([#7440](https://github.com/sveltejs/svelte/issues/7440))
* Strip leading newline after `<pre>` and `<textarea>` ([#7264](https://github.com/sveltejs/svelte/issues/7264)) * Fix handling of void tags in `<svelte:element>` ([#7449](https://github.com/sveltejs/svelte/issues/7449))
* Fix local transition for `{#key}` block ([#5950](https://github.com/sveltejs/svelte/issues/5950)) * Fix handling of boolean attributes in `<svelte:element>` ([#7478](https://github.com/sveltejs/svelte/issues/7478))
* Fix errorneous setting `textContent` for `<template>` element ([#7297](https://github.com/sveltejs/svelte/pull/7297)) * Add special style scoping handling of `[open]` selectors on `<dialog>` elements ([#7495](https://github.com/sveltejs/svelte/issues/7494))
## 3.47.0 ## 3.47.0
@ -931,7 +1068,7 @@ Also:
## 3.5.1 ## 3.5.1
* Accommodate webpack idiosyncracies * Accommodate webpack idiosyncrasies
## 3.5.0 ## 3.5.0
@ -1133,7 +1270,7 @@ Also:
## 2.12.0 ## 2.12.0
* Initialise actions on mount rather than hydrate ([#1653](https://github.com/sveltejs/svelte/pull/1653)) * Initialise actions on mount rather than hydrate ([#1653](https://github.com/sveltejs/svelte/pull/1653))
* Allow non-existent components to be destroyed ([#1677](https://github.com/sveltejs/svelte/pull/1677)) * Allow nonexistent components to be destroyed ([#1677](https://github.com/sveltejs/svelte/pull/1677))
* Pass AMD ID from CLI correctly ([#1672](https://github.com/sveltejs/svelte/pull/1672)) * Pass AMD ID from CLI correctly ([#1672](https://github.com/sveltejs/svelte/pull/1672))
* Minor AST tweaks ([#1673](https://github.com/sveltejs/svelte/pull/1673), [#1674](https://github.com/sveltejs/svelte/pull/1674)) * Minor AST tweaks ([#1673](https://github.com/sveltejs/svelte/pull/1673), [#1674](https://github.com/sveltejs/svelte/pull/1674))
* Reduce code duplication in component initialisation ([#1670](https://github.com/sveltejs/svelte/pull/1670)) * Reduce code duplication in component initialisation ([#1670](https://github.com/sveltejs/svelte/pull/1670))

@ -11,9 +11,9 @@ The [Open Source Guides](https://opensource.guide/) website has a collection of
There are many ways to contribute to Svelte, and many of them do not involve writing any code. Here's a few ideas to get started: There are many ways to contribute to Svelte, and many of them do not involve writing any code. Here's a few ideas to get started:
- Simply start using Svelte. Go through the [Getting Started](https://svelte.dev/blog/the-easiest-way-to-get-started) guide. Does everything work as expected? If not, we're always looking for improvements. Let us know by [opening an issue](#reporting-new-issues). - Simply start using Svelte. Go through the [Getting Started](https://svelte.dev/docs#getting-started) guide. Does everything work as expected? If not, we're always looking for improvements. Let us know by [opening an issue](#reporting-new-issues).
- Look through the [open issues](https://github.com/sveltejs/svelte/issues). A good starting point would be issues tagged [good first issue](https://github.com/sveltejs/svelte/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22). Provide workarounds, ask for clarification, or suggest labels. Help [triage issues](#triaging-issues-and-pull-requests). - Look through the [open issues](https://github.com/sveltejs/svelte/issues). A good starting point would be issues tagged [good first issue](https://github.com/sveltejs/svelte/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22). Provide workarounds, ask for clarification, or suggest labels. Help [triage issues](#triaging-issues-and-pull-requests).
- If you find an issue you would like to fix, [open a pull request](#your-first-pull-request). - If you find an issue you would like to fix, [open a pull request](#pull-requests).
- Read through our [tutorials](https://svelte.dev/tutorial/basics). If you find anything that is confusing or can be improved, you can make edits by clicking "Edit this chapter" at the bottom left of the tutorial page. - Read through our [tutorials](https://svelte.dev/tutorial/basics). If you find anything that is confusing or can be improved, you can make edits by clicking "Edit this chapter" at the bottom left of the tutorial page.
- Take a look at the [features requested](https://github.com/sveltejs/svelte/labels/feature%20request) by others in the community and consider opening a pull request if you see something you want to work on. - Take a look at the [features requested](https://github.com/sveltejs/svelte/labels/feature%20request) by others in the community and consider opening a pull request if you see something you want to work on.
@ -24,65 +24,63 @@ Contributions are very welcome. If you think you need help planning your contrib
One great way you can contribute to the project without writing any code is to help triage issues and pull requests as they come in. One great way you can contribute to the project without writing any code is to help triage issues and pull requests as they come in.
- Ask for more information if you believe the issue does not provide all the details required to solve it. - Ask for more information if you believe the issue does not provide all the details required to solve it.
- Suggest [labels](https://github.com/sveltejs/svelte/labels) that can help categorize issues.
- Flag issues that are stale or that should be closed. - Flag issues that are stale or that should be closed.
- Ask for test plans and review code. - Ask for test plans and review code.
## Bugs ## Our process
We use [GitHub issues](https://github.com/sveltejs/svelte/issues) for our public bugs. If you would like to report a problem, take a look around and see if someone already opened an issue about it. If you are certain this is a new unreported bug, you can submit a [bug report](#reporting-new-issues). ### RFCs
If you have questions about using Svelte, contact us on Discord at [svelte.dev/chat](https://svelte.dev/chat), and we will do our best to answer your questions. If you'd like to propose an implementation for a large new feature or change then please [create an RFC](https://github.com/sveltejs/rfcs) to discuss it up front.
If you see anything you'd like to be implemented, create a [feature request issue](https://github.com/sveltejs/svelte/issues/new?template=feature_request.md) ### Roadmap
## Reporting new issues When deciding where to contribute, you may wish to take a look at [our roadmap](https://svelte.dev/roadmap). The Svelte team generally works on a single major effort at a time. This has a couple benefits for us as maintainers. First, it allows us to focus and make noticeable progress in an area being proactive rather than reactive. Secondly, it allows us to handle related issues and PRs together. By batching issues and PRs together were able to ensure implementations and fixes holistically address the set of problems and use cases encountered by our users.
When [opening a new issue](https://github.com/sveltejs/svelte/issues/new/choose), always make sure to fill out the issue template. **This step is very important!** Not doing so may result in your issue not being managed in a timely fashion. Don't take this personally if this happens, and feel free to open a new issue once you've gathered all the information required by the template. ### Maintainer meetings
- **One issue, one bug:** Please report a single bug per issue. The maintainers meet on the final Saturday of each month. While these meetings are not open publicly, we will report back by leaving a comment on each issue discussed. We will generally discuss items aligning with our roadmap, but major PRs needing discussion amongst the maintainers can be added to the agenda for the monthly maintainers meeting. However, we typically are only able to get to a couple of items that are not aligned with our current priority.
- **Provide reproduction steps:** List all the steps necessary to reproduce the issue. The person reading your bug report should be able to follow these steps to reproduce your issue with minimal effort. If possible, use the [REPL](https://svelte.dev/repl) to create your reproduction.
## RFCs ### Prioritization
If you'd like to propose an implementation for a large new feature or change then please [create an RFC](https://github.com/sveltejs/rfcs) to discuss it up front. We do our best to review PRs and RFCs as they are sent, but it is difficult to keep up. We welcome help in reviewing PRs, RFC, and issues. If an item aligns with the current priority on our [roadmap](https://svelte.dev/roadmap), it is more likely to be reviewed quickly. PRs to the most important and active ones repositories get reviewed more quickly while PRs to smaller inactive repos may sit for a bit before we periodically come by and review the pending PRs in a batch.
## Installation ## Bugs
1. Ensure you have [npm](https://www.npmjs.com/get-npm) installed. We use [GitHub issues](https://github.com/sveltejs/svelte/issues) for our public bugs. If you would like to report a problem, take a look around and see if someone already opened an issue about it. If you are certain this is a new unreported bug, you can submit a [bug report](#reporting-new-issues).
1. After cloning the repository, run `npm install` in the root of the repository.
1. To start a development server, run `npm run dev`.
## Pull requests If you have questions about using Svelte, contact us on Discord at [svelte.dev/chat](https://svelte.dev/chat), and we will do our best to answer your questions.
### Your first pull request If you see anything you'd like to be implemented, create a [feature request issue](https://github.com/sveltejs/svelte/issues/new?template=feature_request.md)
So you have decided to contribute code back to upstream by opening a pull request. You've invested a good chunk of time, and we appreciate it. We will do our best to work with you and get the PR looked at. ### Reporting new issues
Working on your first Pull Request? You can learn how from this free video series: When [opening a new issue](https://github.com/sveltejs/svelte/issues/new/choose), always make sure to fill out the issue template. **This step is very important!** Not doing so may result in your issue not being managed in a timely fashion. Don't take this personally if this happens, and feel free to open a new issue once you've gathered all the information required by the template.
- **One issue, one bug:** Please report a single bug per issue.
- **Provide reproduction steps:** List all the steps necessary to reproduce the issue. The person reading your bug report should be able to follow these steps to reproduce your issue with minimal effort. If possible, use the [REPL](https://svelte.dev/repl) to create your reproduction.
[**How to Contribute to an Open Source Project on GitHub**](https://egghead.io/courses/how-to-contribute-to-an-open-source-project-on-github) ## Pull requests
### Proposing a change ### Proposing a change
If you would like to request a new feature or enhancement but are not yet thinking about opening a pull request, you can also file an issue with [feature template](https://github.com/sveltejs/svelte/issues/new?template=feature_request.md). If you would like to request a new feature or enhancement but are not yet thinking about opening a pull request, you can also file an issue with [feature template](https://github.com/sveltejs/svelte/issues/new?template=feature_request.yml).
If you're only fixing a bug, it's fine to submit a pull request right away, but we still recommend that you file an issue detailing what you're fixing. This is helpful in case we don't accept that specific fix but want to keep track of the issue. If you're only fixing a bug, it's fine to submit a pull request right away, but we still recommend that you file an issue detailing what you're fixing. This is helpful in case we don't accept that specific fix but want to keep track of the issue.
### Sending a pull request Small pull requests are much easier to review and more likely to get merged.
Small pull requests are much easier to review and more likely to get merged. Make sure the PR does only one thing, otherwise please split it. ### Installation
Please make sure the following is done when submitting a pull request: 1. Ensure you have [npm](https://www.npmjs.com/get-npm) installed.
1. After cloning the repository, run `npm install` in the root of the repository.
1. To start a development server, run `npm run dev`.
1. Fork [the repository](https://github.com/sveltejs/svelte) and create your branch from `master`. ### Creating a branch
1. Describe your **test plan** in your pull request description. Make sure to test your changes.
1. Make sure your code lints (`npm run lint`).
1. Make sure your tests pass (`npm run test`).
All pull requests should be opened against the `master` branch. Fork [the repository](https://github.com/sveltejs/svelte) and create your branch from `master`. If you've never sent a GitHub pull request before, you can learn how from [this free video series](https://egghead.io/courses/how-to-contribute-to-an-open-source-project-on-github).
#### Test plan ### Testing
A good test plan has the exact commands you ran and their output, provides screenshots or videos if the pull request changes UI. A good test plan has the exact commands you ran and their output, provides screenshots or videos if the pull request changes UI.
@ -110,6 +108,25 @@ Test samples are kept in `/test/xxx/samples` folder.
1. Tests suites like `css`, `js`, `server-side-rendering` asserts that the generated output has to match the content in the `.expected` file. For example, in the `js` test suites, the generated js code is compared against the content in `expected.js`. 1. Tests suites like `css`, `js`, `server-side-rendering` asserts that the generated output has to match the content in the `.expected` file. For example, in the `js` test suites, the generated js code is compared against the content in `expected.js`.
1. To update the content of the `.expected` file, run the test with `--update` flag. (`npm run test --update`) 1. To update the content of the `.expected` file, run the test with `--update` flag. (`npm run test --update`)
### Style guide
[Eslint](https://eslint.org) will catch most styling issues that may exist in your code. You can check the status of your code styling by simply running `npm run lint`.
#### Code conventions
- `snake_case` for internal variable names and methods.
- `camelCase` for public variable names and methods.
### Sending your pull request
Please make sure the following is done when submitting a pull request:
1. Describe your **test plan** in your pull request description. Make sure to test your changes.
1. Make sure your code lints (`npm run lint`).
1. Make sure your tests pass (`npm run test`).
All pull requests should be opened against the `master` branch. Make sure the PR does only one thing, otherwise please split it.
#### Breaking changes #### Breaking changes
When adding a new breaking change, follow this template in your pull request: When adding a new breaking change, follow this template in your pull request:
@ -123,19 +140,10 @@ When adding a new breaking change, follow this template in your pull request:
- **Severity (number of people affected x effort)**: - **Severity (number of people affected x effort)**:
``` ```
### What happens next?
The core Svelte team will be monitoring for pull requests. Do help us by making your pull request easy to review by following the guidelines above.
## Style guide
[Eslint](https://eslint.org) will catch most styling issues that may exist in your code. You can check the status of your code styling by simply running `npm run lint`.
### Code conventions
- `snake_case` for internal variable names and methods.
- `camelCase` for public variable names and methods.
## License ## License
By contributing to Svelte, you agree that your contributions will be licensed under its [MIT license](https://github.com/sveltejs/svelte/blob/master/LICENSE). By contributing to Svelte, you agree that your contributions will be licensed under its [MIT license](https://github.com/sveltejs/svelte/blob/master/LICENSE).
## Questions
Feel free to ask in [#contributing](https://discord.com/channels/457912077277855764/750401468569354431) on [Discord](https://svelte.dev/chat) if you have questions about our process, how to proceed, etc.

@ -1,4 +1,4 @@
Copyright (c) 2016-22 [these people](https://github.com/sveltejs/svelte/graphs/contributors) Copyright (c) 2016-23 [these people](https://github.com/sveltejs/svelte/graphs/contributors)
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

@ -20,6 +20,11 @@ Svelte is an MIT-licensed open source project with its ongoing development made
Funds donated via Open Collective will be used for compensating expenses related to Svelte's development such as hosting costs. If sufficient donations are received, funds may also be used to support Svelte's development more directly. Funds donated via Open Collective will be used for compensating expenses related to Svelte's development such as hosting costs. If sufficient donations are received, funds may also be used to support Svelte's development more directly.
## Roadmap
You may view [our roadmap](https://svelte.dev/roadmap) if you'd like to see what we're currently working on.
## Development ## Development
Pull requests are encouraged and always welcome. [Pick an issue](https://github.com/sveltejs/svelte/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc) and help us out! Pull requests are encouraged and always welcome. [Pick an issue](https://github.com/sveltejs/svelte/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc) and help us out!
@ -64,7 +69,7 @@ npm run test -- -g transition
## svelte.dev ## svelte.dev
The source code for https://svelte.dev, including all the documentation, lives in the [site](site) directory. The site is built with [SvelteKit](https://kit.svelte.dev). The source code for https://svelte.dev lives in the [sites](https://github.com/sveltejs/sites) repository, with all the documentation in the [site/content](site/content) directory. The site is built with [SvelteKit](https://kit.svelte.dev).
### Is svelte.dev down? ### Is svelte.dev down?

1584
elements/index.d.ts vendored

File diff suppressed because it is too large Load Diff

@ -0,0 +1,3 @@
{
"types": "./index.d.ts"
}

@ -0,0 +1,28 @@
// This script generates the TypeScript definitions
const { execSync } = require('child_process');
const { readFileSync, writeFileSync } = require('fs');
try {
execSync('tsc -p src/compiler --emitDeclarationOnly && tsc -p src/runtime --emitDeclarationOnly');
} catch (err) {
console.error(err.stderr.toString());
throw err;
}
// We need to add these types to the .d.ts files here because if we add them before building, the build will fail,
// because the TS->JS transformation doesn't know these exports are types and produces code that fails at runtime.
// We can't use `export type` syntax either because the TS version we're on doesn't have this feature yet.
function modify(path, modifyFn) {
const content = readFileSync(path, 'utf8');
writeFileSync(path, modifyFn(content));
}
modify(
'types/runtime/index.d.ts',
content => content.replace('SvelteComponentTyped', 'SvelteComponentTyped, ComponentType, ComponentConstructorOptions, ComponentProps, ComponentEvents')
);
modify(
'types/compiler/index.d.ts',
content => content + '\nexport { CompileOptions, ModuleFormat, EnableSourcemap, CssHashGetter } from "./interfaces"'
);

4116
package-lock.json generated

File diff suppressed because it is too large Load Diff

@ -1,6 +1,6 @@
{ {
"name": "svelte", "name": "svelte",
"version": "3.47.0", "version": "3.55.1",
"description": "Cybernetically enhanced web apps", "description": "Cybernetically enhanced web apps",
"module": "index.mjs", "module": "index.mjs",
"main": "index", "main": "index",
@ -17,6 +17,7 @@
"easing", "easing",
"motion", "motion",
"action", "action",
"elements",
"README.md" "README.md"
], ],
"exports": { "exports": {
@ -75,6 +76,9 @@
"import": "./transition/index.mjs", "import": "./transition/index.mjs",
"require": "./transition/index.js" "require": "./transition/index.js"
}, },
"./elements": {
"types": "./elements/index.d.ts"
},
"./ssr": { "./ssr": {
"types": "./types/runtime/index.d.ts", "types": "./types/runtime/index.d.ts",
"import": "./ssr.mjs", "import": "./ssr.mjs",
@ -86,17 +90,17 @@
}, },
"types": "types/runtime/index.d.ts", "types": "types/runtime/index.d.ts",
"scripts": { "scripts": {
"test": "mocha --exit", "test": "npm run test:unit && npm run test:integration",
"test:unit": "mocha --require sucrase/register --recursive src/**/__test__.ts --exit", "test:integration": "mocha --exit",
"quicktest": "mocha", "test:unit": "mocha --config .mocharc.unit.js --exit",
"quicktest": "mocha --exit",
"build": "rollup -c && npm run tsd", "build": "rollup -c && npm run tsd",
"prepare": "npm run build", "prepare": "node scripts/skip_in_ci.js npm run build",
"dev": "rollup -cw", "dev": "rollup -cw",
"pretest": "npm run build",
"posttest": "agadoo internal/index.mjs", "posttest": "agadoo internal/index.mjs",
"prepublishOnly": "node check_publish_env.js && npm run lint && npm test", "prepublishOnly": "node check_publish_env.js && npm run lint && npm run build && npm test",
"tsd": "tsc -p src/compiler --emitDeclarationOnly && tsc -p src/runtime --emitDeclarationOnly", "tsd": "node ./generate-type-definitions.js",
"lint": "eslint \"{src,test}/**/*.{ts,js}\"" "lint": "eslint \"{src,test}/**/*.{ts,js}\" --cache"
}, },
"repository": { "repository": {
"type": "git", "type": "git",
@ -116,48 +120,44 @@
"homepage": "https://svelte.dev", "homepage": "https://svelte.dev",
"devDependencies": { "devDependencies": {
"@ampproject/remapping": "^0.3.0", "@ampproject/remapping": "^0.3.0",
"@jridgewell/sourcemap-codec": "^1.4.14",
"@rollup/plugin-commonjs": "^11.0.0", "@rollup/plugin-commonjs": "^11.0.0",
"@rollup/plugin-json": "^4.0.1", "@rollup/plugin-json": "^4.0.1",
"@rollup/plugin-node-resolve": "^6.0.0", "@rollup/plugin-node-resolve": "^11.2.1",
"@rollup/plugin-replace": "^2.3.0", "@rollup/plugin-replace": "^2.3.0",
"@rollup/plugin-sucrase": "^3.1.0", "@rollup/plugin-sucrase": "^3.1.0",
"@rollup/plugin-typescript": "^2.0.1", "@rollup/plugin-typescript": "^2.0.1",
"@rollup/plugin-virtual": "^2.0.0", "@rollup/plugin-virtual": "^2.0.0",
"@sveltejs/eslint-config": "github:sveltejs/eslint-config#v5.8.0", "@sveltejs/eslint-config": "github:sveltejs/eslint-config#v5.8.0",
"@types/aria-query": "^5.0.0",
"@types/mocha": "^7.0.0", "@types/mocha": "^7.0.0",
"@types/node": "^8.10.53", "@types/node": "^8.10.53",
"@typescript-eslint/eslint-plugin": "^4.31.2", "@typescript-eslint/eslint-plugin": "^5.22.0",
"@typescript-eslint/parser": "^4.31.2", "@typescript-eslint/parser": "^5.22.0",
"acorn": "^8.4.1", "acorn": "^8.8.1",
"agadoo": "^1.1.0", "agadoo": "^2.0.0",
"aria-query": "^5.1.1",
"axobject-query": "^3.1.1",
"code-red": "^0.2.5", "code-red": "^0.2.5",
"css-tree": "^1.1.2", "css-tree": "^2.2.1",
"eslint": "^7.32.0", "eslint": "^8.26.0",
"eslint-plugin-import": "^2.24.2", "eslint-plugin-import": "^2.26.0",
"eslint-plugin-svelte3": "^3.2.1", "eslint-plugin-svelte3": "^4.0.0",
"estree-walker": "^3.0.0", "estree-walker": "^3.0.1",
"is-reference": "^3.0.0", "is-reference": "^3.0.0",
"jsdom": "^15.2.1", "jsdom": "^15.2.1",
"kleur": "^3.0.3", "kleur": "^4.1.5",
"locate-character": "^2.0.5", "locate-character": "^2.0.5",
"magic-string": "^0.25.3", "magic-string": "^0.25.3",
"mocha": "^7.0.0", "mocha": "^7.0.0",
"periscopic": "^3.0.4", "periscopic": "^3.0.4",
"puppeteer": "^2.0.0", "puppeteer": "^2.0.0",
"rollup": "^1.27.14", "rollup": "^1.27.14",
"source-map": "^0.7.3", "source-map": "^0.7.4",
"source-map-support": "^0.5.13", "source-map-support": "^0.5.21",
"sourcemap-codec": "^1.4.8", "tiny-glob": "^0.2.9",
"tiny-glob": "^0.2.6", "tslib": "^2.4.1",
"tslib": "^2.0.3", "typescript": "^3.7.5",
"typescript": "^3.7.5" "util": "^0.12.5"
},
"nyc": {
"include": [
"compiler/svelte.js",
"shared.js"
],
"sourceMap": true,
"instrument": true
} }
} }

@ -108,8 +108,18 @@ export default [
input: 'src/compiler/index.ts', input: 'src/compiler/index.ts',
plugins: [ plugins: [
replace({ replace({
__VERSION__: pkg.version __VERSION__: pkg.version,
'process.env.NODE_DEBUG': false // appears inside the util package
}), }),
{
resolveId(id) {
// util is a built-in module in Node.js, but we want a self-contained compiler bundle
// that also works in the browser, so we load its polyfill instead
if (id === 'util') {
return require.resolve('./node_modules/util'); // just 'utils' would resolve this to the built-in module
}
}
},
resolve(), resolve(),
commonjs({ commonjs({
include: ['node_modules/**'] include: ['node_modules/**']

@ -0,0 +1,91 @@
/** ----------------------------------------------------------------------
This script gets a list of global objects/functions of browser.
This process is simple for now, so it is handled without AST parser.
Please run `node scripts/globals-extractor.mjs` at the project root.
see: https://github.com/microsoft/TypeScript/tree/main/lib
---------------------------------------------------------------------- */
import http from 'https';
import fs from 'fs';
const GLOBAL_TS_PATH = './src/compiler/utils/globals.ts';
// MEMO: add additional objects/functions which existed in `src/compiler/utils/names.ts`
// before this script was introduced but could not be retrieved by this process.
const SPECIALS = ['global', 'globalThis', 'InternalError', 'process', 'undefined'];
const get_url = (name) => `https://raw.githubusercontent.com/microsoft/TypeScript/main/lib/lib.${name}.d.ts`;
const extract_name = (split) => split.match(/^[a-zA-Z0-9_$]+/)[0];
const extract_functions_and_references = (name, data) => {
const functions = [];
const references = [];
data.split('\n').forEach(line => {
const trimmed = line.trim();
const split = trimmed.replace(/[\s+]/, ' ').split(' ');
if (split[0] === 'declare' && split[1] !== 'type') {
functions.push(extract_name(split[2]));
} else if (trimmed.startsWith('/// <reference')) {
const matched = trimmed.match(/ lib="(.+)"/);
const reference = matched && matched[1];
if (reference) references.push(reference);
}
});
return { functions, references };
};
const do_get = (url) => new Promise((resolve, reject) => {
http.get(url, (res) => {
let body = '';
res.setEncoding('utf8');
res.on('data', (chunk) => body += chunk);
res.on('end', () => resolve(body));
}).on('error', (e) => {
console.error(e.message);
reject(e);
});
});
const fetched_names = new Set();
const get_functions = async (name) => {
const res = [];
if (fetched_names.has(name)) return res;
fetched_names.add(name);
const body = await do_get(get_url(name));
const { functions, references } = extract_functions_and_references(name, body);
res.push(...functions);
const chile_functions = await Promise.all(references.map(get_functions));
chile_functions.forEach(i => res.push(...i));
return res;
};
const build_output = (functions) => {
const sorted = Array.from(new Set(functions.sort()));
return `\
/** ----------------------------------------------------------------------
This file is automatically generated by \`scripts/globals-extractor.mjs\`.
Generated At: ${new Date().toISOString()}
---------------------------------------------------------------------- */
export default new Set([
${sorted.map((i) => `\t'${i}'`).join(',\n')}
]);
`;
};
const get_exists_globals = () => {
const regexp = /^\s*["'](.+)["'],?\s*$/;
return fs.readFileSync(GLOBAL_TS_PATH, 'utf8')
.split('\n')
.filter(line => line.match(regexp))
.map(line => line.match(regexp)[1]);
};
(async () => {
const globals = get_exists_globals();
const new_globals = await get_functions('es2021.full');
globals.forEach((g) => new_globals.push(g));
SPECIALS.forEach((g) => new_globals.push(g));
fs.writeFileSync(GLOBAL_TS_PATH, build_output(new_globals));
})();

@ -0,0 +1,7 @@
if (process.env.SKIP_PREPARE) {
console.log('Skipped "prepare" script');
} else {
const { execSync } = require("child_process");
const command = process.argv.slice(2).join(" ");
execSync(command, { stdio: "inherit" });
}

@ -1,55 +0,0 @@
---
title: "Frameworks without the framework: why didn't we think of this sooner?"
description: You can't write serious applications in vanilla JavaScript without hitting a complexity wall. But a compiler can do it for you.
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
> Wait, this new framework has a *runtime*? Ugh. Thanks, I'll pass.
> ** front end developers in 2018**
We're shipping too much code to our users. Like a lot of front end developers, I've been in denial about that fact, thinking that it was fine to serve 100kb of JavaScript on page load just use [one less .jpg!](https://twitter.com/miketaylr/status/227056824275333120) and that what *really* mattered was performance once your app was already interactive.
But I was wrong. 100kb of .js isn't equivalent to 100kb of .jpg. It's not just the network time that'll kill your app's startup performance, but the time spent parsing and evaluating your script, during which time the browser becomes completely unresponsive. On mobile, those milliseconds rack up very quickly.
If you're not convinced that this is a problem, follow [Alex Russell](https://twitter.com/slightlylate) on Twitter. Alex [hasn't been making many friends in the framework community lately](https://twitter.com/slightlylate/status/728355959022587905), but he's not wrong. But the proposed alternative to using frameworks like Angular, React and Ember [Polymer](https://www.polymer-project.org/1.0/) hasn't yet gained traction in the front end world, and it's certainly not for a lack of marketing.
Perhaps we need to rethink the whole thing.
## What problem do frameworks *really* solve?
The common view is that frameworks make it easier to manage the complexity of your code: the framework abstracts away all the fussy implementation details with techniques like virtual DOM diffing. But that's not really true. At best, frameworks *move the complexity around*, away from code that you had to write and into code you didn't.
Instead, the reason that ideas like React are so wildly and deservedly successful is that they make it easier to manage the complexity of your *concepts*. Frameworks are primarily a tool for structuring your thoughts, not your code.
Given that, what if the framework *didn't actually run in the browser*? What if, instead, it converted your application into pure vanilla JavaScript, just like Babel converts ES2016+ to ES5? You'd pay no upfront cost of shipping a hefty runtime, and your app would get seriously fast, because there'd be no layers of abstraction between your app and the browser.
## Introducing Svelte
Svelte is a new framework that does exactly that. You write your components using HTML, CSS and JavaScript (plus a few extra bits you can [learn in under 5 minutes](https://v2.svelte.dev/guide)), and during your build process Svelte compiles them into tiny standalone JavaScript modules. By statically analysing the component template, we can make sure that the browser does as little work as possible.
The [Svelte implementation of TodoMVC](https://svelte-todomvc.surge.sh/) weighs 3.6kb zipped. For comparison, React plus ReactDOM *without any app code* weighs about 45kb zipped. It takes about 10x as long for the browser just to evaluate React as it does for Svelte to be up and running with an interactive TodoMVC.
And once your app *is* up and running, according to [js-framework-benchmark](https://github.com/krausest/js-framework-benchmark) **Svelte is fast as heck**. It's faster than React. It's faster than Vue. It's faster than Angular, or Ember, or Ractive, or Preact, or Riot, or Mithril. It's competitive with Inferno, which is probably the fastest UI framework in the world, for now, because [Dominic Gannaway](https://twitter.com/trueadm) is a wizard. (Svelte is slower at removing elements. We're [working on it](https://github.com/sveltejs/svelte/issues/26).)
It's basically as fast as vanilla JS, which makes sense because it *is* vanilla JS  just vanilla JS that you didn't have to write.
## But that's not the important thing
Well, it *is* important performance matters a great deal. What's really exciting about this approach, though, is that we can finally solve some of the thorniest problems in web development.
Consider interoperability. Want to `npm install cool-calendar-widget` and use it in your app? Previously, you could only do that if you were already using (a correct version of) the framework that the widget was designed for if `cool-calendar-widget` was built in React and you're using Angular then, well, hard cheese. But if the widget author used Svelte, apps that use it can be built using whatever technology you like. (On the TODO list: a way to convert Svelte components into web components.)
Or [code splitting](https://twitter.com/samccone/status/797528710085652480). It's a great idea (only load the code the user needs for the initial view, then get the rest later), but there's a problem even if you only initially serve one React component instead of 100, *you still have to serve React itself*. With Svelte, code splitting can be much more effective, because the framework is embedded in the component, and the component is tiny.
Finally, something I've wrestled with a great deal as an open source maintainer: your users always want *their* features prioritised, and underestimate the cost of those features to people who don't need them. A framework author must always balance the long-term health of the project with the desire to meet their users' needs. That's incredibly difficult, because it's hard to anticipate much less articulate the consequences of incremental bloat, and it takes serious soft skills to tell people (who may have been enthusiastically evangelising your tool up to that point) that their feature isn't important enough. But with an approach like Svelte's, many features can be added with absolutely no cost to people who don't use them, because the code that implements those features just doesn't get generated by the compiler if it's unnecessary.
## We're just getting started
Svelte is very new. There's a lot of work still left to do creating build tool integrations, adding a server-side renderer, hot reloading, transitions, more documentation and examples, starter kits, and so on.
But you can already build rich components with it, which is why we've gone straight to a stable 1.0.0 release. [Read the guide](https://v2.svelte.dev/guide), [try it out in the REPL](/repl), and head over to [GitHub](https://github.com/sveltejs/svelte) to help kickstart the next era of front end development.

@ -1,66 +0,0 @@
---
title: The easiest way to get started with Svelte
description: This'll only take a minute.
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
Svelte is a [new kind of framework](/blog/frameworks-without-the-framework). Rather than putting a `<script src='svelte.js'>` tag on the page, or bringing it into your app with `import` or `require`, Svelte is a compiler that works behind the scenes to turn your component files into beautifully optimised JavaScript.
Because of that, getting started with it can be a little bit confusing at first. How, you might reasonably ask, do you make a Svelte app?
## 1. Use the REPL
The [Svelte REPL](/repl) (Read-Eval-Print Loop) is the easiest way to begin. This is an interactive environment that allows you to modify code and instantly see the result.
You can choose from a list of [examples](/examples/), click the [REPL](/repl) link, and then tweak them until they do what you want.
<aside><p>You'll need to have <a href="https://nodejs.org/">Node.js</a> installed, and know how to use the terminal</p></aside>
At some point, your app will outgrow the REPL. Click the **download** button to save a `svelte-app.zip` file to your computer and uncompress it.
Open a terminal window and set the project up...
```bash
cd /path/to/svelte-app
npm install
```
...then start up a development server:
```bash
npm run dev
```
This will serve your app on [localhost:8080](http://localhost:8080) and rebuild it with [Rollup](https://rollupjs.org) every time you make a change to the files in `svelte-app/src`.
## 2. Use degit
When you download from the REPL, you're getting a customised version of the [sveltejs/template](https://github.com/sveltejs/template) repo. You can skip messing around with zip files by using [degit](https://github.com/Rich-Harris/degit), a project scaffolding tool.
In the terminal, you can instantly create a new project like so:
```bash
npx degit sveltejs/template my-svelte-project
cd my-svelte-project
# to use TypeScript run:
# node scripts/setupTypeScript.js
npm install
npm run dev
```
This will create a new project in the `my-svelte-project` directory, install its dependencies, and start a server on http://localhost:8080.
You can find more information about using TypeScript [here](/blog/svelte-and-typescript).
Once you've tinkered a bit and understood how everything fits together, you can fork [sveltejs/template](https://github.com/sveltejs/template) and start doing this instead:
```bash
npx degit your-name/template my-new-project
```
And that's it! Do `npm run build` to create a production-ready version of your app, and check the project template's [README](https://github.com/sveltejs/template/blob/master/README.md) for instructions on how to easily deploy your app to the web with [Vercel](https://vercel.com) or [Surge](http://surge.sh/).
You're not restricted to using Rollup — there are also integrations for [webpack](https://github.com/sveltejs/svelte-loader), [Browserify](https://github.com/tehshrike/sveltify) and others, or you can use the [Svelte CLI](https://github.com/sveltejs/svelte-cli) (Update from 2019: with Svelte 3 the CLI was deprecated and we now use [sirv-cli](https://www.npmjs.com/package/sirv-cli) in our template. Feel free to use whatever tool you like!) or the [API](https://github.com/sveltejs/svelte/tree/v2#api) directly. If you make a project template using one of these tools, please share it with the [Svelte Discord chatroom](chat), or via [@sveltejs](https://twitter.com/sveltejs) on Twitter!

@ -1,78 +0,0 @@
---
title: The zen of Just Writing CSS
description: I would say this is the future, but we're already doing it.
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
It's fashionable to dislike CSS. There are lots of reasons why that's the case, but it boils down to this: CSS is *unpredictable*. If you've never had the experience of tweaking a style rule and accidentally breaking some layout that you thought was completely unrelated — usually when you're trying to ship — then you're either new at this or you're a much better programmer than the rest of us.
So the JavaScript community rolled up its sleeves and got to work. Over the last couple of years, there's been a Cambrian explosion of libraries aimed at making CSS behave, collectively referred to as *CSS-in-JS*.
What you might not realise is that **the biggest problems with CSS can be solved without CSS-in-JS**. Without those problems, writing CSS isn't just tolerable — it's enjoyable. And you don't have to find solutions to the additional problems that CSS-in-JS introduces.
This article isn't in any way intended as criticism of the hard work the CSS-in-JS community has done. It's one of the most active corners of the JS ecosystem, and new ideas are springing up every week. Instead, my purpose is to illustrate why an alternative approach — based on Single File Components with real CSS — is so damn delightful.
## The biggest problem with CSS
Everything in CSS is global. Because of that, styles intended for one bit of markup often end up affecting another. Because of *that*, developers often resort to wild namespacing conventions (not 'rules', since they're very difficult to enforce) that mostly just increase your risk of RSI.
It gets worse when you're working on a team. No-one dares touch styles authored by someone else, because it's often unclear what they're doing, what markup they apply to, and what disasters will unfold if you remove them.
The consequence of all this is the **append-only stylesheet**. There's no way of knowing which code can safely be removed, so it's common to undo some existing style with another, more specific style — even on relatively small projects.
## Single File Components change all that
The idea behind SFCs is simple: you write your components in an HTML file that (optionally) contains a `<style>` and `<script>` attribute describing the component's styles and behaviour. Svelte, Ractive, Vue and Polymer all follow this basic pattern.
<aside>
<p><a href="/blog/frameworks-without-the-framework">Read the introductory blog post</a> if you're new to Svelte. Or <a href="https://twitter.com/padolsey/status/899717303234908160">read</a> <a href="https://twitter.com/sveltejs/status/901818357644701696">the</a> <a href="https://twitter.com/sveltejs/status/901818106309476352">testimonials</a>.</p>
</aside>
(For the rest of this article we'll be using Svelte, obviously. But if the idea of using a template language makes you shudder — your fears are misplaced, but that's a topic for another day — then just use Vue which lets you use JSX in your SFCs.)
Several wonderful things happen as a result:
* Your styles are *scoped to the component*. No more leakage, no more unpredictable cascade. And no more sesquipedalian classnames designed to prevent conflicts.
* You don't need to go spelunking through your folder structure to find the rules that are breaking your stuff.
* The compiler (in Svelte's case) can **identify and remove unused styles**. No more append-only stylesheets!
Let's see what that looks like in practice.
<figure>
<video controls poster='https://svelte-technology-assets.surge.sh/just-write-css.jpg'>
<source type='video/mp4' src='https://svelte-technology-assets.surge.sh/just-write-css.mp4'>
</video>
<figcaption>
Is this what they mean by 'use the platform'?
</figcaption>
</figure>
Every code editor already knows about CSS, so there's a good chance that you'll get autocomplete, linting, syntax highlighting and so on — all without additional JS-fatigue-inducing tools.
And because it's real CSS, rather than some camelCased quotes-everywhere impostor, we can take advantage of the 'tweak in devtools, paste back into our source code' workflow, which I personally couldn't live without. Notice that we get CSS sourcemaps out of the box, so you can instantly pinpoint the lines in question. It's hard to overstate the importance of this: when you're in WYSIWYG mode, you're not thinking in terms of your component tree, so having a robust way to figure out *where these damn styles came from* is essential. Doubly so if someone else originally wrote the component. (I promise you, this is the single biggest productivity boost to your CSS workflow. If you're writing styles without sourcemaps, you are almost certainly wasting a lot of time. I know I was.)
Svelte transforms your selectors (using an attribute that's also applied to affected elements, though the exact mechanism is unimportant and subject to change) to achieve the scoping. It warns on and removes any unused rules, then it minifies the result and lets you write it out to a `.css` file. There's also an experimental new option to compile to web components, using shadow DOM to encapsulate the styles, if that's your jam.
This is all possible because your CSS is parsed (with [css-tree](https://github.com/csstree/csstree)) and statically analysed in the context of your markup. Static analysis opens the doors to all kinds of exciting future possibilities — smarter optimisations, a11y hints — that are much harder if your styles are computed dynamically at runtime. We're just getting started.
## But we can add tools to do [x]!
If your reaction to the video was 'fine, but if we use TypeScript and write plugins for each editor then we can get all the autocomplete and syntax highlighting stuff' — in other words, if you believe that in order to achieve parity with CSS it makes sense to build, document, promote and maintain a fleet of ancillary projects — then, well, you and I may never see eye to eye!
## We don't have all the answers — yet
Having said all that, CSS-in-JS does point to answers to some lingering questions:
* How can we install styles from npm?
* How can we reuse constants that are defined in a single place?
* How can we compose declarations?
Personally, I haven't found these issues to outweigh the benefits of the approach outlined above. You may well have a different set of priorities, and they may be reason enough for you to abandon CSS.
But at the end of the day, you have to know CSS anyway. Love it or loathe it, you must at least *learn* it. As custodians of the web, we have a choice: create abstractions that steepen the web dev learning curve yet further, or work together to fix the bad parts of CSS. I know which I choose.

@ -1,84 +0,0 @@
---
title: "Sapper: Towards the ideal web app framework"
description: Taking the next-plus-one step
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
> Quickstart for the impatient: [the Sapper docs](https://sapper.svelte.dev), and the [starter template](https://github.com/sveltejs/sapper-template)
If you had to list the characteristics of the perfect Node.js web application framework, you'd probably come up with something like this:
1. It should do server-side rendering, for fast initial loads and no caveats around SEO
2. As a corollary, your app's codebase should be universal — write once for server *and* client
3. The client-side app should *hydrate* the server-rendered HTML, attaching event listeners (and so on) to existing elements rather than re-rendering them
4. Navigating to subsequent pages should be instantaneous
5. Offline, and other Progressive Web App characteristics, must be supported out of the box
6. Only the JavaScript and CSS required for the first page should load initially. That means the framework should do automatic code-splitting at the route level, and support dynamic `import(...)` for more granular manual control
7. No compromise on performance
8. First-rate developer experience, with hot module reloading and all the trimmings
9. The resulting codebase should be easy to grok and maintain
10. It should be possible to understand and customise every aspect of the system — no webpack configs locked up in the framework, and as little hidden 'plumbing' as possible
11. Learning the entire framework in under an hour should be easy, and not just for experienced developers
[Next.js](https://github.com/zeit/next.js) is close to this ideal. If you haven't encountered it yet, I strongly recommend going through the tutorials at [learnnextjs.com](https://learnnextjs.com). Next introduced a brilliant idea: all the pages of your app are files in a `your-project/pages` directory, and each of those files is just a React component.
Everything else flows from that breakthrough design decision. Finding the code responsible for a given page is easy, because you can just look at the filesystem rather than playing 'guess the component name'. Project structure bikeshedding is a thing of the past. And the combination of SSR (server-side rendering) and code-splitting — something the React Router team [gave up on](https://reacttraining.com/react-router/web/guides/code-splitting), declaring 'Godspeed those who attempt the server-rendered, code-split apps' — is trivial.
But it's not perfect. As churlish as it might be to list the flaws in something *so, so good*, there are some:
* Next uses something called 'route masking' to create nice URLs (e.g. `/blog/hello-world` instead of `/post?slug=hello-world`). This undermines the guarantee about directory structure corresponding to app structure, and forces you to maintain configuration that translates between the two forms
* All your routes are assumed to be universal 'pages'. But it's very common to need routes that only render on the server, such as a 301 redirect or an [API endpoint](/blog/sapper-towards-the-ideal-web-app-framework.json) that serves the data for your pages, and Next doesn't have a great solution for this. You can add logic to your `server.js` file to handle these cases, but it feels at odds with the declarative approach taken for pages
* To use the client-side router, links can't be standard `<a>` tags. Instead, you have to use framework-specific `<Link>` components, which is impossible in the markdown content for a blog post such as this one, for example
The real problem, though, is that all that goodness comes for a price. The simplest possible Next app — a single 'hello world' page that renders some static text — involves 66kb of gzipped JavaScript. Unzipped, it's 204kb, which is a non-trivial amount of code for a mobile device to parse at a time when performance is a critical factor determining whether or not your users will stick around. And that's the *baseline*.
We can do better!
## The compiler-as-framework paradigm shift
[Svelte introduced a radical idea](/blog/frameworks-without-the-framework): what if your UI framework wasn't a framework at all, but a compiler that turned your components into standalone JavaScript modules? Instead of using a library like React or Vue, which knows nothing about your app and must therefore be a one-size-fits-all solution, we can ship highly-optimised vanilla JavaScript. Just the code your app needs, and without the memory and performance overhead of solutions based on a virtual DOM.
The JavaScript world is [moving towards this model](https://tomdale.net/2017/09/compilers-are-the-new-frameworks/). [Stencil](https://stenciljs.com), a Svelte-inspired framework from the Ionic team, compiles to web components. [Glimmer](https://glimmerjs.com) *doesn't* compile to standalone JavaScript (the pros and cons of which deserve a separate blog post), but the team is doing some fascinating research around compiling templates to bytecode. (React is [getting in on the action](https://twitter.com/trueadm/status/944908776896978946), though their current research focuses on optimising your JSX app code, which is arguably more similar to the ahead-of-time optimisations that Angular, Ractive and Vue have been doing for a few years.)
What happens if we use the new model as a starting point?
## Introducing Sapper
<aside><p>The <a href="https://sapper.svelte.dev/docs#Why_the_name">name comes from</a> the term for combat engineers, and is also short for Svelte app maker</p></aside>
[Sapper](https://sapper.svelte.dev) is the answer to that question. **Sapper is a Next.js-style framework that aims to meet the eleven criteria at the top of this article while dramatically reducing the amount of code that gets sent to the browser.** It's implemented as Express-compatible middleware, meaning it's easy to understand and customise.
The same 'hello world' app that took 204kb with React and Next weighs just 7kb with Sapper. That number is likely to fall further in the future as we explore the space of optimisation possibilities, such as not shipping any JavaScript *at all* for pages that aren't interactive, beyond the tiny Sapper runtime that handles client-side routing.
What about a more 'real world' example? Conveniently, the [RealWorld](https://github.com/gothinkster/realworld) project, which challenges frameworks to develop an implementation of a Medium clone, gives us a way to find out. The [Sapper implementation](https://github.com/sveltejs/realworld) takes 39.6kb (11.8kb zipped) to render an interactive homepage.
<aside><p>Code-splitting isn't free — if the reference implementation used code-splitting, it would be larger still</p></aside>
The entire app costs 132.7kb (39.9kb zipped), which is significantly smaller than the reference React/Redux implementation at 327kb (85.7kb), but even if it was as large it would *feel* faster because of code-splitting. And that's a crucial point. We're told we need to code-split our apps, but if your app uses a traditional framework like React or Vue then there's a hard lower bound on the size of your initial code-split chunk — the framework itself, which is likely to be a significant portion of your total app size. With the Svelte approach, that's no longer the case.
But size is only part of the story. Svelte apps are also extremely performant and memory-efficient, and the framework includes powerful features that you would sacrifice if you chose a 'minimal' or 'simple' UI library.
## Trade-offs
The biggest drawback for many developers evaluating Sapper would be 'but I like React, and I already know how to use it', which is fair.
If you're in that camp, I'd invite you to at least try alternative frameworks. You might be pleasantly surprised! The [Sapper RealWorld](https://github.com/sveltejs/realworld) implementation totals 1,201 lines of source code, compared to 2,377 for the reference implementation, because you're able to express concepts very concisely using Svelte's template syntax (which [takes all of five minutes to master](https://v2.svelte.dev/guide#template-syntax)). You get [scoped CSS](/blog/the-zen-of-just-writing-css), with unused style removal and minification built-in, and you can use preprocessors like LESS if you want. You no longer need to use Babel. SSR is ridiculously fast, because it's just string concatenation. And we recently introduced [svelte/store](https://v2.svelte.dev/guide#state-management), a tiny global store that synchronises state across your component hierarchy with zero boilerplate. The worst that can happen is that you'll end up feeling vindicated!
But there are trade-offs nonetheless. Some people have a pathological aversion to any form of 'template language', and maybe that applies to you. JSX proponents will clobber you with the 'it's just JavaScript' mantra, and therein lies React's greatest strength, which is that it is infinitely flexible. That flexibility comes with its own set of trade-offs, but we're not here to discuss those.
And then there's *ecosystem*. The universe around React in particular — the devtools, editor integrations, ancillary libraries, tutorials, StackOverflow answers, hell, even job opportunities — is unrivalled. While it's true that citing 'ecosystem' as the main reason to choose a tool is a sign that you're stuck on a local maximum, apt to be marooned by the rising waters of progress, it's still a major point in favour of incumbents.
## Roadmap
We're not at version 1.0.0 yet, and a few things may change before we get there. Once we do (soon!), there are a lot of exciting possibilities.
I believe the next frontier of web performance is 'whole-app optimisation'. Currently, Svelte's compiler operates at the component level, but a compiler that understood the boundaries *between* those components could generate even more efficient code. The React team's [Prepack research](https://twitter.com/trueadm/status/944908776896978946) is predicated on a similar idea, and the Glimmer team is doing some interesting work in this space. Svelte and Sapper are well positioned to take advantage of these ideas.
Speaking of Glimmer, the idea of compiling components to bytecode is one that we'll probably steal in 2018. A framework like Sapper could conceivably determine which compilation mode to use based on the characteristics of your app. It could even serve JavaScript for the initial route for the fastest possible startup time, then lazily serve a bytecode interpreter for subsequent routes, resulting in the optimal combination of startup size and total app size.
Mostly, though, we want the direction of Sapper to be determined by its users. If you're the kind of developer who enjoys life on the bleeding edge and would like to help shape the future of how we build web apps, please join us on [GitHub](https://github.com/sveltejs/svelte) and [Discord](chat).

@ -1,204 +0,0 @@
---
title: Svelte v2 is out!
description: Here's what you need to know
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
<aside>Our motto is 'move slowly and break things'. No, wait, that came out wrong...</aside>
Almost a year after we first started talking about version 2 on the Svelte issue tracker, it's finally time to make some breaking changes. This blog post will explain what changed, why it changed, and what you need to do to bring your apps up to date.
## tl;dr
Each of these items is described in more depth below. If you get stuck, ask for help in our friendly [Discord chatroom](chat).
- Install Svelte v2 from npm
- Upgrade your templates with [svelte-upgrade](https://github.com/sveltejs/svelte-upgrade)
- Remove calls to `component.observe`, or add the `observe` method from [svelte-extras](https://github.com/sveltejs/svelte-extras)
- Rewrite calls to `component.get('foo')` as `component.get().foo`
- Return `destroy` from your custom event handlers, rather than `teardown`
- Make sure you're not passing numeric string props to components
## New template syntax
The most visible change: we've made some improvements to the template syntax.
A common piece of feedback we heard was 'ewww, Mustache' or 'ewww, Handlebars'. A lot of people who used string-based templating systems in a previous era of web development *really* dislike them. Because Svelte adopted the `{{curlies}}` from those languages, a lot of people assumed that we somehow shared the limitations of those tools, such as weird scoping rules or an inability to use arbitrary JavaScript expressions.
<aside>If you need to show an actual `{` character, it's as easy as `&amp;#123;`</aside>
Beyond that, JSX proved that double curlies are unnecessary. So we've made our templates more... svelte, by adopting single curlies. The result feels much lighter to look at and is more pleasant to type:
```html
<h1>Hello {name}!</h1>
```
There are a few other updates. But you don't need to make them manually — just run [svelte-upgrade](https://github.com/sveltejs/svelte-upgrade) on your codebase:
```bash
npx svelte-upgrade v2 src
```
This assumes any `.html` files in `src` are Svelte components. You can specify whichever directory you like, or target a different directory — for example, you'd do `npx svelte-upgrade v2 routes` to update a [Sapper](https://sapper.svelte.technology) app.
To see the full set of changes, consult the [svelte-upgrade README](https://github.com/sveltejs/svelte-upgrade#svelte-v2-syntax-changes).
## Computed properties
Another thing that people often found confusing about Svelte is the way computed properties work. To recap, if you had a component with this...
```js
export default {
computed: {
d: (a, b, c) => a = b + c
}
};
```
...then Svelte would first look at the function arguments to see which values `d` depended on, and then it would write code that updated `d` whenever those values changed, by injecting them into the function. That's cool, because it allows you to derive complex values from your component's inputs without worrying about when they need to recomputed, but it's also... *weird*. JavaScript doesn't work that way!
In v2, we use [destructuring](http://www.jstips.co/en/javascript/use-destructuring-in-function-parameters/) instead:
```js
export default {
computed: {
d: ({ a, b, c }) => a = b + c
}
};
```
The Svelte compiler can still see which values `d` depends on, but it's no longer injecting values — it just passes the component state object into each computed property.
Again, you don't need to make this change manually — just run svelte-upgrade on your components, as shown above.
## Sorry, IE11. It's not you, it's... well actually, yeah. It's you
Svelte v1 was careful to only emit ES5 code, so that you wouldn't be forced to faff around with transpilers in order to use it. But it's 2018 now, and almost all browsers support modern JavaScript. By ditching the ES5 constraint, we can generate leaner code.
If you need to support IE11 and friends, you will need to use a transpiler like [Babel](https://babeljs.io/repl) or [Bublé](https://buble.surge.sh/).
## New lifecycle hooks
In addition to `oncreate` and `ondestroy`, Svelte v2 adds two more [lifecycle hooks](https://v2.svelte.dev/guide#lifecycle-hooks) for responding to state changes:
```js
export default {
onstate({ changed, current, previous }) {
// this fires before oncreate, and
// whenever state changes
},
onupdate({ changed, current, previous }) {
// this fires after oncreate, and
// whenever the DOM has been updated
// following a state change
}
};
```
You can also listen to those events programmatically:
```js
component.on('state', ({ changed, current, previous }) => {
// ...
});
```
## component.observe
With the new lifecycle hooks, we no longer need the `component.observe(...)` method:
```js
// before
export default {
oncreate() {
this.observe('foo', foo => {
console.log(`foo is now ${foo}`);
});
}
};
// after
export default {
onstate({ changed, current }) {
if (changed.foo) {
console.log(`foo is now ${current.foo}`);
}
}
};
```
This shrinks the amount of code Svelte needs to generate, and gives you more flexibility. For example, it's now very easy to take action when any one of *several* properties have changed, such as redrawing a canvas without debouncing several observers.
However, if you prefer to use `component.observe(...)`, then you can install it from [svelte-extras](https://github.com/sveltejs/svelte-extras):
```js
import { observe } from 'svelte-extras';
export default {
methods: {
observe
}
};
```
## component.get
This method no longer takes an optional `key` argument — instead, it always returns the entire state object:
```js
// before
const foo = this.get('foo');
const bar = this.get('bar');
// after
const { foo, bar } = this.get();
```
This change might seem annoying initially, but it's the right move: among other things, it's likely to play better with type systems as we explore that space more fully in future.
## event_handler.destroy
If your app has [custom event handlers](https://v2.svelte.dev/guide#custom-event-handlers), they must return an object with a `destroy` method, *not* a `teardown` method (this aligns event handlers with the component API).
## No more type coercion
Previously, numeric values passed to components were treated as numbers:
```html
<Counter start='1'/>
```
That causes unexpected behaviour, and has been changed: if you need to pass a literal number, do so as an expression:
```html
<Counter start={1}/>
```
## Compiler changes
In most cases you'll never need to deal with the compiler directly, so this shouldn't require any action on your part. It's worth noting anyway: the compiler API has changed. Instead of an object with a mish-mash of properties, the compiler now returns `js`, `css`, `ast` and `stats`:
```js
const { js, css, ast, stats } = svelte.compile(source, options);
```
`js` and `css` are both `{ code, map }` objects, where `code` is a string and `map` is a sourcemap. The `ast` is an abstract syntax tree of your component, and the `stats` object contains metadata about the component, and information about the compilation.
Before, there was a `svelte.validate` method which checked your component was valid. That's been removed — if you want to check a component without actually compiling it, just pass the `generate: false` option.
## My app is broken! Help!
Hopefully this covers everything, and the update should be easier for you than it was for us. But if you find bugs, or discover things that aren't mentioned here, swing by [Discord chatroom](chat) or raise an issue on the [tracker](https://github.com/sveltejs/svelte/issues).

@ -1,29 +0,0 @@
---
title: Using CSS-in-JS with Svelte
description: You don't need to, but you can
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
CSS is a core part of any web app. By extension, a UI framework that doesn't have a built-in way to add styles to your components is unfinished.
That's why Svelte allows you to add CSS in a component's `<style>` tag. Co-locating your CSS with your markup means we can [solve the biggest problems developers face when writing CSS](/blog/the-zen-of-just-writing-css) without introducing new ones, all while providing a rather nice development experience.
But Svelte's style handling does have some limitations. It's too difficult to share styles between components, or apply app-level optimisations. These are areas we plan to address in future versions, but in the meantime if you need those things you can use any framework-agnostic CSS-in-JS library.
## For example
Here, we're using [Emotion](https://emotion.sh) to generate scoped class names that can be used across multiple components:
<div class="max">
<iframe
title="Aphrodite example"
src="/repl/embed?example=blog-svelte-css-in-js"
scrolling="no"
></iframe>
</div>
It's important to note that most CSS-in-JS libraries have a runtime library, and many don't support statically extracting styles out into a separate <code>.css</code> file at build time (which is essential for the best performance). You should therefore only use CSS-in-JS if it's necessary for your application!
Note that you can mix-and-match — you can still use Svelte's built-in CSS handling alongside a CSS-in-JS library.

@ -1,149 +0,0 @@
---
title: Virtual DOM is pure overhead
description: Let's retire the 'virtual DOM is fast' myth once and for all
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
If you've used JavaScript frameworks in the last few years, you've probably heard the phrase 'the virtual DOM is fast', often said to mean that it's faster than the *real* DOM. It's a surprisingly resilient meme — for example people have asked how Svelte can be fast when it doesn't use a virtual DOM.
It's time to take a closer look.
## What is the virtual DOM?
In many frameworks, you build an app by creating `render()` functions, like this simple [React](https://reactjs.org/) component:
```js
function HelloMessage(props) {
return (
<div className="greeting">
Hello {props.name}
</div>
);
}
```
You can do the same thing without JSX...
```js
function HelloMessage(props) {
return React.createElement(
'div',
{ className: 'greeting' },
'Hello ',
props.name
);
}
```
...but the result is the same — an object representing how the page should now look. That object is the virtual DOM. Every time your app's state updates (for example when the `name` prop changes), you create a new one. The framework's job is to *reconcile* the new one against the old one, to figure out what changes are necessary and apply them to the real DOM.
## How did the meme start?
Misunderstood claims about virtual DOM performance date back to the launch of React. In [Rethinking Best Practices](https://www.youtube.com/watch?v=x7cQ3mrcKaY), a seminal 2013 talk by former React core team member Pete Hunt, we learned the following:
> This is actually extremely fast, primarily because most DOM operations tend to be slow. There's been a lot of performance work on the DOM, but most DOM operations tend to drop frames.
<figure>
<img alt="Pete Hunt at JSConfEU 2013" src="/media/rethinking-best-practices.jpg">
<figcaption>Screenshot from <a href="https://www.youtube.com/watch?v=x7cQ3mrcKaY">Rethinking Best Practices</a> at JSConfEU 2013</figcaption>
</figure>
But hang on a minute! The virtual DOM operations are *in addition to* the eventual operations on the real DOM. The only way it could be faster is if we were comparing it to a less efficient framework (there were plenty to go around back in 2013!), or arguing against a straw man — that the alternative is to do something no-one actually does:
```js
onEveryStateChange(() => {
document.body.innerHTML = renderMyApp();
});
```
Pete clarifies soon after...
> React is not magic. Just like you can drop into assembler with C and beat the C compiler, you can drop into raw DOM operations and DOM API calls and beat React if you wanted to. However, using C or Java or JavaScript is an order of magnitude performance improvement because you don't have to worry...about the specifics of the platform. With React you can build applications without even thinking about performance and the default state is fast.
...but that's not the part that stuck.
## So... is the virtual DOM *slow*?
Not exactly. It's more like 'the virtual DOM is usually fast enough', but with certain caveats.
The original promise of React was that you could re-render your entire app on every single state change without worrying about performance. In practice, I don't think that's turned out to be accurate. If it was, there'd be no need for optimisations like `shouldComponentUpdate` (which is a way of telling React when it can safely skip a component).
Even with `shouldComponentUpdate`, updating your entire app's virtual DOM in one go is a lot of work. A while back, the React team introduced something called React Fiber which allows the update to be broken into smaller chunks. This means (among other things) that updates don't block the main thread for long periods of time, though it doesn't reduce the total amount of work or the time an update takes.
## Where does the overhead come from?
Most obviously, [diffing isn't free](https://twitter.com/pcwalton/status/1015694528857047040). You can't apply changes to the real DOM without first comparing the new virtual DOM with the previous snapshot. To take the earlier `HelloMessage` example, suppose the `name` prop changed from 'world' to 'everybody'.
1. Both snapshots contain a single element. In both cases it's a `<div>`, which means we can keep the same DOM node
2. We enumerate all the attributes on the old `<div>` and the new one to see if any need to be changed, added or removed. In both cases we have a single attribute — a `className` with a value of `"greeting"`
3. Descending into the element, we see that the text has changed, so we'll need to update the real DOM
Of these three steps, only the third has value in this case, since — as is the case in the vast majority of updates — the basic structure of the app is unchanged. It would be much more efficient if we could skip straight to step 3:
```js
if (changed.name) {
text.data = name;
}
```
(This is almost exactly the update code that Svelte generates. Unlike traditional UI frameworks, Svelte is a compiler that knows at *build time* how things could change in your app, rather than waiting to do the work at *run time*.)
## It's not just the diffing though
The diffing algorithms used by React and other virtual DOM frameworks are fast. Arguably, the greater overhead is in the components themselves. You wouldn't write code like this...
```js
function StrawManComponent(props) {
const value = expensivelyCalculateValue(props.foo);
return (
<p>the value is {value}</p>
);
}
```
...because you'd be carelessly recalculating `value` on every update, regardless of whether `props.foo` had changed. But it's extremely common to do unnecessary computation and allocation in ways that seem much more benign:
```js
function MoreRealisticComponent(props) {
const [selected, setSelected] = useState(null);
return (
<div>
<p>Selected {selected ? selected.name : 'nothing'}</p>
<ul>
{props.items.map(item =>
<li>
<button onClick={() => setSelected(item)}>
{item.name}
</button>
</li>
)}
</ul>
</div>
);
}
```
Here, we're generating a new array of virtual `<li>` elements — each with their own inline event handler — on every state change, regardless of whether `props.items` has changed. Unless you're unhealthily obsessed with performance, you're not going to optimise that. There's no point. It's plenty fast enough. But you know what would be even faster? *Not doing that.*
<aside><p><a href="https://reactjs.org/docs/hooks-intro.html">React Hooks</a> doubles down on defaulting to doing unnecessary work, with <a href="https://twitter.com/thekitze/status/1078582382201131008">predictable results</a>.</p></aside>
The danger of defaulting to doing unnecessary work, even if that work is trivial, is that your app will eventually succumb to 'death by a thousand cuts' with no clear bottleneck to aim at once it's time to optimise.
Svelte is explicitly designed to prevent you from ending up in that situation.
## Why do frameworks use the virtual DOM then?
It's important to understand that virtual DOM *isn't a feature*. It's a means to an end, the end being declarative, state-driven UI development. Virtual DOM is valuable because it allows you to build apps without thinking about state transitions, with performance that is *generally good enough*. That means less buggy code, and more time spent on creative tasks instead of tedious ones.
But it turns out that we can achieve a similar programming model without using virtual DOM — and that's where Svelte comes in.

@ -1,21 +0,0 @@
---
title: Svelte on The Changelog
description: Listen to the interview here
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
Earlier this month, I had the privilege of appearing on [The Changelog](https://changelog.com/podcast), a podcast about software development. We had a fun (for me) and wide-ranging conversation:
* life as a coder inside a newsroom
* the big compilers-as-frameworks trend
* scalability
* the [Great Divide](https://css-tricks.com/the-great-divide/)
...and, most importantly, Svelte 3.
Unless you hang out in our [Discord server](chat) or follow [@sveltejs](https://twitter.com/sveltejs) on Twitter, you might not know that Svelte 3 is just around the corner, and it's going to be a huge release. We've rethought the developer experience from the ground up, and while it *will* be a nuisance if you need to upgrade a Svelte 2 app (more on that soon) we think you're going to love it.
On the podcast [Adam](https://twitter.com/adamstac), [Jerod](https://twitter.com/jerodsanto) and I talk about some of the changes and why we're making them. You can listen here or on the [podcast page](https://changelog.com/podcast/332).
<audio data-theme="night" style="width: 100%" data-src="https://changelog.com/podcast/332/embed" src="https://cdn.changelog.com/uploads/podcast/332/the-changelog-332.mp3" preload="none" class="changelog-episode" controls></audio><p><a href="https://changelog.com/podcast/332">The Changelog 332: A UI framework without the framework</a> Listen on <a href="https://changelog.com/">Changelog.com</a></p><script async src="//cdn.changelog.com/embed.js"></script>

@ -1,65 +0,0 @@
---
title: Setting up your editor
description: Instructions for configuring linting and syntax highlighting
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
draft: true
---
*__Coming soon__*
This post will walk you through setting up your editor so that it recognises Svelte files:
* eslint-plugin-svelte3
* svelte-vscode
* associating .svelte files with HTML in VSCode, Sublime, etc.
## Atom
To treat `*.svelte` files as HTML, open *__Edit → Config...__* and add the following lines to your `core` section:
```cson
"*":
core:
customFileTypes:
"text.html.basic": [
"svelte"
]
```
## Vim/Neovim
You can use the [coc-svelte extension](https://github.com/coc-extensions/coc-svelte) which utilises the official language-server.
As an alternative you can treat all `*.svelte` files as HTML. Add the following line to your `init.vim`:
```
au! BufNewFile,BufRead *.svelte set ft=html
```
To temporarily turn on HTML syntax highlighting for the current buffer, use:
```
:set ft=html
```
To set the filetype for a single file, use a [modeline](https://vim.fandom.com/wiki/Modeline_magic):
```
<!-- vim: set ft=html :-->
```
## Visual Studio Code
We recommend using the official [Svelte for VS Code extension](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode).
## JetBrains WebStorm
The [Svelte Framework Integration](https://plugins.jetbrains.com/plugin/12375-svelte/) can be used to add support for Svelte to WebStorm, or other Jetbrains IDEs. Consult the [WebStorm plugin installation guide](https://www.jetbrains.com/help/webstorm/managing-plugins.html) on the JetBrains website for more details.
## Sublime Text 3
Open any `.svelte` file.
Go to *__View → Syntax → Open all with current extension as... → HTML__*.

@ -1,107 +0,0 @@
---
title: Svelte for new developers
description: Never used Node.js or the command line? No problem
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
This short guide is designed to help you — someone who has looked at the [tutorial](/tutorial) and wants to start creating Svelte apps, but doesn't have a ton of experience using JavaScript build tooling — get up and running.
If there are things that don't make sense, or that we're glossing over, feel free to [raise an issue](https://github.com/sveltejs/svelte/issues) or [suggest edits to this page](https://github.com/sveltejs/svelte/blob/master/site/content/blog/2019-04-16-svelte-for-new-developers.md) that will help us help more people.
If you get stuck at any point following this guide, the best place to ask for help is in the [chatroom](https://svelte.dev/chat).
## First things first
You'll be using the *command line*, also known as the terminal. On Windows, you can access it by running **Command Prompt** from the Start menu; on a Mac, hit `Cmd` and `Space` together to bring up **Spotlight**, then start typing `Terminal.app`. On most Linux systems, `Ctrl-Alt-T` brings up the command line.
The command line is a way to interact with your computer (or another computer! but that's a topic for another time) with more power and control than the GUI (graphical user interface) that most people use day-to-day.
Once on the command line, you can navigate the filesystem using `ls` (`dir` on Windows) to list the contents of your current directory, and `cd` to change the current directory. For example, if you had a `Development` directory of your projects inside your home directory, you would type
```bash
cd Development
```
to go to it. From there, you could create a new project directory with the `mkdir` command:
```bash
mkdir svelte-projects
cd svelte-projects
```
A full introduction to the command line is out of the scope of this guide, but here are a few more useful commands:
* `cd ..` — navigates to the parent of the current directory
* `cat my-file.txt` — on Mac/Linux (`type my-file.txt` on Windows), lists the contents of `my-file.txt`
* `open .` (or `start .` on Windows) — opens the current directory in Finder or File Explorer
## Installing Node.js
[Node](https://nodejs.org/en/) is a way to run JavaScript on the command line. It's used by many tools, including Svelte. If you don't yet have it installed, the easiest way is to download the latest version straight from the [website](https://nodejs.org/en/).
Once installed, you'll have access to three new commands:
* `node my-file.js` — runs the JavaScript in `my-file.js`
* `npm [subcommand]` — [npm](https://www.npmjs.com/) is a way to install 'packages' that your application depends on, such as the [svelte](https://www.npmjs.com/package/svelte) package
* `npx [subcommand]` — a convenient way to run programs available on npm without permanently installing them
## Installing a text editor
To write code, you need a good editor. The most popular choice is [Visual Studio Code](https://code.visualstudio.com/) or VSCode, and justifiably so — it's well-designed and fully-featured, and has a wealth of extensions ([including one for Svelte](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode), which provides syntax highlighting and diagnostic messages when you're writing components).
## Creating a project
We're going to follow the instructions in part two of [The easiest way to get started with Svelte](/blog/the-easiest-way-to-get-started).
First, we'll use npx to run [degit](https://github.com/Rich-Harris/degit), a program for cloning project templates from [GitHub](https://github.com) and other code storage websites. You don't have to use a project template, but it means you have to do a lot less setup work. You will need to have [Git](https://git-scm.com/) installed in order to use degit. (Eventually you'll probably have to learn [Git](https://git-scm.com/) itself, which most programmers use to manage their projects.)
On the command line, navigate to where you want to create a new project, then type the following lines (you can paste the whole lot, but you'll develop better muscle memory if you get into the habit of writing each line out one at a time then running it):
```bash
npx degit sveltejs/template my-svelte-project
cd my-svelte-project
npm install
```
This creates a new directory, `my-svelte-project`, adds files from the [sveltejs/template](https://github.com/sveltejs/template) code repository, and installs a number of packages from npm. Open the directory in your text editor and take a look around. The app's 'source code' lives in the `src` directory, while the files your app can load are in `public`.
In the `package.json` file, there is a section called `"scripts"`. These scripts define shortcuts for working with your application — `dev`, `build` and `start`. To launch your app in development mode, type the following:
```bash
npm run dev
```
Running the `dev` script starts a program called [Rollup](https://rollupjs.org/guide/en/). Rollup's job is to take your application's source files (so far, just `src/main.js` and `src/App.svelte`), pass them to other programs (including Svelte, in our case) and convert them into the code that will actually run when you open the application in a browser.
Speaking of which, open a browser and navigate to http://localhost:8080. This is your application running on a local *web server* (hence 'localhost') on port 8080.
Try changing `src/App.svelte` and saving it. The application will reload with your changes.
## Building your app
In the last step, we were running the app in 'development mode'. In dev mode, Svelte adds extra code that helps with debugging, and Rollup skips the final step where your app's JavaScript is compressed using [Terser](https://terser.org/).
When you share your app with the world, you want to build it in 'production mode', so that it's as small and efficient as possible for end users. To do that, use the `build` command:
```bash
npm run build
```
Your `public` directory now contains a compressed `bundle.js` file containing your app's JavaScript. You can run it like so:
```bash
npm run start
```
This will run the app on http://localhost:8080.
## Next steps
To share your app with the world you'll need to *deploy* it. There are many ways to do so — some are listed in the `README.md` file inside your project.

@ -1,164 +0,0 @@
---
title: Write less code
description: The most important metric you're not paying attention to
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
All code is buggy. It stands to reason, therefore, that the more code you have to write the buggier your apps will be.
Writing more code also takes more time, leaving less time for other things like optimisation, nice-to-have features, or being outdoors instead of hunched over a laptop.
In fact it's widely acknowledged that [project development time](https://blog.codinghorror.com/diseconomies-of-scale-and-lines-of-code/) and [bug count](https://www.mayerdan.com/ruby/2012/11/11/bugs-per-line-of-code-ratio) grow *quadratically*, not linearly, with the size of a codebase. That tracks with our intuitions: a ten-line pull request will get a level of scrutiny rarely applied to a 100-line one. And once a given module becomes too big to fit on a single screen, the cognitive effort required to understand it increases significantly. We compensate by refactoring and adding comments — activities that almost always result in *more* code. It's a vicious cycle.
Yet while we obsess — rightly! — over performance numbers, bundle size and anything else we can measure, we rarely pay attention to the amount of code we're writing.
## Readability is important
I'm certainly not claiming that we should use clever tricks to scrunch our code into the most compact form possible at the expense of readability. Nor am I claiming that reducing *lines* of code is necessarily a worthwhile goal, since it encourages turning readable code like this...
```js
for (let i = 0; i <= 100; i += 1) {
if (i % 2 === 0) {
console.log(`${i} is even`);
}
}
```
...into something much harder to parse:
```js
for (let i = 0; i <= 100; i += 1) if (i % 2 === 0) console.log(`${i} is even`);
```
Instead, I'm claiming that we should favour languages and patterns that allow us to naturally write less code.
## Yes, I'm talking about Svelte
Reducing the amount of code you have to write is an explicit goal of Svelte. To illustrate, let's look at a very simple component implemented in React, Vue and Svelte. First, the Svelte version:
<div class="max">
<iframe
title="Simple component example"
src="/repl/embed?example=blog-write-less-code"
scrolling="no"
></iframe>
</div>
How would we build this in React? It would probably look something like this:
```js
import React, { useState } from 'react';
export default () => {
const [a, setA] = useState(1);
const [b, setB] = useState(2);
function handleChangeA(event) {
setA(+event.target.value);
}
function handleChangeB(event) {
setB(+event.target.value);
}
return (
<div>
<input type="number" value={a} onChange={handleChangeA}/>
<input type="number" value={b} onChange={handleChangeB}/>
<p>{a} + {b} = {a + b}</p>
</div>
);
};
```
Here's an equivalent component in Vue:
```html
<template>
<div>
<input type="number" v-model.number="a">
<input type="number" v-model.number="b">
<p>{{a}} + {{b}} = {{a + b}}</p>
</div>
</template>
<script>
export default {
data: function() {
return {
a: 1,
b: 2
};
}
};
</script>
```
<aside>
<p>I'm counting by copying the source code to the clipboard and running `pbpaste | wc -c` in my terminal</p>
</aside>
In other words, it takes 442 characters in React, and 263 characters in Vue, to achieve something that takes 145 characters in Svelte. The React version is literally three times larger!
It's unusual for the difference to be *quite* so obvious — in my experience, a React component is typically around 40% larger than its Svelte equivalent. Let's look at the features of Svelte's design that enable you to express ideas more concisely:
### Top-level elements
In Svelte, a component can have as many top-level elements as you like. In React and Vue, a component must have a single top-level element — in React's case, trying to return two top-level elements from a component function would result in syntactically invalid code. (You can use a fragment — `<>` instead of a `<div>`, but it's the same basic idea, and still results in an extra level of indentation).
In Vue, your markup must be wrapped in a `<template>` element, which I'd argue is redundant.
### Bindings
In React, we have to respond to input events ourselves:
```js
function handleChangeA(event) {
setA(+event.target.value);
}
```
This isn't just boring plumbing that takes up extra space on the screen, it's also extra surface area for bugs. Conceptually, the value of the input is bound to the value of `a` and vice versa, but that relationship isn't cleanly expressed — instead we have two tightly-coupled but physically separate chunks of code (the event handler and the `value={a}` prop). Not only that, but we have to remember to coerce the string value with the `+` operator, otherwise `2 + 2` will equal `22` instead of `4`.
Like Svelte, Vue does have a way of expressing the binding — the `v-model` attribute, though again we have to be careful to use `v-model.number` even though it's a numeric input.
### State
In Svelte, you update local component state with an assignment operator:
```js
let count = 0;
function increment() {
count += 1;
}
```
In React, we use the `useState` hook:
```js
const [count, setCount] = useState(0);
function increment() {
setCount(count + 1);
}
```
This is much *noisier* — it expresses the exact same concept but with over 60% more characters. As you're reading the code, you have to do that much more work to understand the author's intent.
In Vue, meanwhile, we have a default export with a `data` function that returns an object literal with properties corresponding to our local state. Things like helper functions and child components can't simply be imported and used in the template, but must instead be 'registered' by attaching them to the correct part of the default export.
## Death to boilerplate
These are just some of the ways that Svelte helps you build user interfaces with a minimum of fuss. There are plenty of others — for example, [reactive declarations](/tutorial/reactive-declarations) essentially do the work of React's `useMemo`, `useCallback` and `useEffect` without the boilerplate (or indeed the garbage collection overhead of creating inline functions and arrays on each state change).
How? By choosing a different set of constraints. Because [Svelte is a compiler](/blog/frameworks-without-the-framework), we're not bound to the peculiarities of JavaScript: we can *design* a component authoring experience, rather than having to fit it around the semantics of the language. Paradoxically, this results in *more* idiomatic code — for example using variables naturally rather than via proxies or hooks — while delivering significantly more performant apps.

@ -1,97 +0,0 @@
---
title: "Svelte 3: Rethinking reactivity"
description: It's finally here
author: Rich Harris
authorURL: https://twitter.com/Rich_Harris
---
After several months of being just days away, we are over the moon to announce the stable release of Svelte 3. This is a huge release representing hundreds of hours of work by many people in the Svelte community, including invaluable feedback from beta testers who have helped shape the design every step of the way.
We think you're going to love it.
## What is Svelte?
Svelte is a component framework — like React or Vue — but with an important difference. Traditional frameworks allow you to write *declarative* state-driven code, but there's a penalty: the browser must do extra work to convert those declarative structures into DOM operations, using techniques like [virtual DOM diffing](/blog/virtual-dom-is-pure-overhead) that eat into your frame budget and tax the garbage collector.
Instead, Svelte runs at *build time*, converting your components into highly efficient *imperative* code that surgically updates the DOM. As a result, you're able to write ambitious applications with excellent performance characteristics.
The first version of Svelte was all about [testing a hypothesis](/blog/frameworks-without-the-framework) — that a purpose-built compiler could generate rock-solid code that delivered a great user experience. The second was a small upgrade that tidied things up a bit.
Version 3 is a significant overhaul. Our focus for the last five or six months has been on delivering an outstanding *developer* experience. It's now possible to write components with [significantly less boilerplate](/blog/write-less-code) than you'll find elsewhere. Try the brand new [tutorial](/tutorial) and see what we mean — if you're familiar with other frameworks we think you'll be pleasantly surprised.
To make that possible we first needed to rethink the concept at the heart of modern UI frameworks: reactivity.
<div class="max">
<figure style="max-width: 960px; margin: 0 auto">
<div style="height: 0; padding: 0 0 57.1% 0; position: relative; margin: 0 auto;">
<iframe style="position: absolute; width: 100%; height: 100%; left: 0; top: 0; margin: 0;" src="https://www.youtube-nocookie.com/embed/AdNJ3fydeao" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
</div>
<figcaption>'Rethinking Reactivity' from <a href="https://www.israel.yglfconf.com/">You Gotta Love Frontend Code Camp</a></figcaption>
</figure>
</div>
## Moving reactivity into the language
In old Svelte, you would tell the computer that some state had changed by calling the `this.set` method:
```js
const { count } = this.get();
this.set({
count: count + 1
});
```
That would cause the component to *react*. Speaking of which, `this.set` is almost identical to the `this.setState` method used in classical (pre-hooks) React:
```js
const { count } = this.state;
this.setState({
count: count + 1
});
```
There are some important technical differences (as I explain in the video above, React is not reactive) but conceptually it's the same thing.
<aside>
<p>In fact, Svelte 3 is basically <a href="https://twitter.com/threepointone/status/1057179801109311488">Sunil's fault</a>.</p>
</aside>
That all changed with the advent of [hooks](https://reactjs.org/docs/hooks-intro.html), which handle state in a very different fashion. Many frameworks started experimenting with their own implementations of hooks, but we quickly concluded it wasn't a direction we wanted to go in. Hooks have some intriguing properties, but they also involve some unnatural code and create unnecessary work for the garbage collector. For a framework that's used in [embedded devices](https://mobile.twitter.com/sveltejs/status/1088500539640418304) as well as animation-heavy interactives, that's no good.
So we took a step back and asked ourselves what kind of API would work for us... and realised that the best API is no API at all. We can just *use the language*. Updating some `count` value — and all the things that depend on it — should be as simple as this:
```js
count += 1;
```
Since we're a compiler, we can do that by instrumenting assignments behind the scenes:
```js
count += 1; $$invalidate('count', count);
```
Importantly, we can do all this without the overhead and complexity of using proxies or accessors. It's just a variable.
## New look
Your components aren't the only thing that's getting a facelift. Svelte itself has a completely new look and feel, thanks to the amazing design work of [Achim Vedam](https://vedam.de/) who created our new logo and website, which has moved from [svelte.technology](https://svelte.technology) to [svelte.dev](https://svelte.dev).
We've also changed our tagline, from 'The magical disappearing UI framework' to 'Cybernetically enhanced web apps'. Svelte has many aspects — outstanding performance, small bundles, accessibility, built-in style encapsulation, declarative transitions, ease of use, the fact that it's a compiler, etc — that focusing on any one of them feels like an injustice to the others. 'Cybernetically enhanced' is designed to instead evoke Svelte's overarching philosophy that our tools should work as intelligent extensions of ourselves — hopefully with a retro, William Gibson-esque twist.
## Upgrading from version 2
If you're an existing Svelte 2 user, I'm afraid there is going to be some manual upgrading involved. In the coming days we'll release a migration guide and an updated version of [svelte-upgrade](https://github.com/sveltejs/svelte-upgrade) which will do the best it can to automate the process, but this *is* a significant change and not everything can be handled automatically.
We don't take this lightly: hopefully once you've experienced Svelte 3 you'll understand why we felt it was necessary to break with the past.
## Still to come
As grueling as this release has been, we're nowhere near finished. We have a ton of ideas for generating smarter, more compact code, and a long feature wish-list. [Sapper](https://sapper.svelte.dev), our Next.js-style app framework, is still in the middle of being updated to use Svelte 3. The [Svelte Native](https://svelte-native.technology/) community project, which allows you to write Android and iOS apps in Svelte, is making solid progress but deserves more complete support from core. We don't yet have the bounty of editor extensions, syntax highlighters, component kits, devtools and so on that other frameworks have, and we should fix that. We *really* want to add first-class TypeScript support.
But in the meantime we think Svelte 3 is the best way to build web apps yet. Take an hour to go through the [tutorial](/tutorial) and we hope to convince you of the same. Either way, we'd love to see you in our [Discord chatroom](https://svelte.dev/chat) and on [GitHub](https://github.com/sveltejs/svelte) — everyone is welcome, especially you.

@ -1,141 +0,0 @@
---
title: Svelte <3 TypeScript
description: Typernetically enhanced web apps
author: Orta Therox
authorURL: https://twitter.com/orta
---
It's been by far the most requested feature for a while, and it's finally here: Svelte officially supports TypeScript.
We think it'll give you a much nicer development experience — one that also scales beautifully to larger Svelte code bases — regardless of whether you use TypeScript or JavaScript.
<figure>
<img alt="Screenshot of TypeScript in Svelte" src="/media/svelte-ts.png">
<figcaption>Image of TypeScript + Svelte in VS Code (theme is <a href="https://marketplace.visualstudio.com/items?itemName=karyfoundation.theme-karyfoundation-themes">Kary Pro</a>.)</figcaption>
</figure>
## Try it now
You can start a new Svelte TypeScript project using the [normal template](https://github.com/sveltejs/template) and by running `node scripts/setupTypeScript.js` before you do anything else:
```bash
npx degit sveltejs/template svelte-typescript-app
cd svelte-typescript-app
node scripts/setupTypeScript.js
```
If you're a VS Code user, make sure you're using the (new) [official extension](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode), which replaces the popular extension by James Birtles.
Later in this blog post, we'll detail the individual steps involved in using TypeScript in an existing Svelte project.
## What does it mean to support TypeScript in Svelte?
TypeScript support in Svelte has been possible for a long time, but you had to mix a lot of disparate tools together and each project ran independently. Today, nearly all of these tools live under the Svelte organization and are maintained by a set of people who take responsibility over the whole pipeline and have common goals.
A week before COVID was declared a pandemic, [I pitched a consolidation](https://github.com/sveltejs/svelte/issues/4518) of the best Svelte tools and ideas from similar dev-ecosystems and provided a set of steps to get first class TypeScript support. Since then, many people have pitched in and written the code to get us there.
When we say that Svelte now supports TypeScript, we mean a few different things:
* You can use TypeScript inside your `<script>` blocks — just add the `lang="ts"` attribute
* Components with TypeScript can be type-checked with the `svelte-check` command
* You get autocompletion hints and type-checking as you're writing components, even in expressions inside markup
* TypeScript files understand the Svelte component API — no more red squiggles when you import a `.svelte` file into a `.ts` module
### How does it work?
To understand the two main parts of TypeScript support, we'll compare it to the technique TypeScript uses to provide dev tools. There is a compiler `tsc` which you run on the command-line to convert `*.ts` to `*.js`, then there is a `TSServer` which is a node API that responds to requests from text editors. The `TSServer` is what provides all the JavaScript and TypeScript realtime introspection for editors while coding, and it has most of the compiler's code inside it.
For Svelte, we have the Svelte compiler, and now we have the [`svelte-language-server`](https://github.com/sveltejs/language-tools/tree/master/packages/language-server#svelte-language-server) which responds to text editor calls via the [Language Server Protocol standard](https://microsoft.github.io//language-server-protocol/overviews/lsp/overview/). First class TypeScript support means that _both_ of these two systems do a good job of handling TypeScript code.
The Svelte compiler support for TypeScript is handled by [Christian Kaisermann](https://github.com/kaisermann)'s [`svelte-preprocess`](https://github.com/sveltejs/svelte-preprocess#svelte-preprocess) which is now an official Svelte project.
For the editor level, we took inspiration from [Pine's](https://github.com/octref) work in the [Vue](https://vuejs.org) ecosystem via [Vetur](https://github.com/vuejs/vetur). Vetur provides an [LSP](https://github.com/vuejs/vetur/blob/master/server), a VS Code extension and a [CLI](https://github.com/vuejs/vetur/blob/master/vti). Svelte now also has an [LSP](https://github.com/sveltejs/language-tools/blob/master/packages/language-server), a [VS Code extension](https://github.com/sveltejs/language-tools/blob/master/packages/svelte-vscode) and a [CLI](https://github.com/sveltejs/language-tools/blob/master/packages/svelte-check).
### `*.svelte` Introspection
For the official Svelte VS Code extension, we built off the foundations which [James Birtles](https://github.com/UnwrittenFun) has created in [`UnwrittenFun/svelte-vscode`](https://github.com/UnwrittenFun/svelte-vscode) and [`UnwrittenFun/svelte-language-server`](https://github.com/UnwrittenFun/svelte-language-server/).
[Simon Holthausen](https://github.com/dummdidumm) and [Lyu, Wei-Da](https://github.com/jasonlyu123) have done great work improving the JavaScript and TypeScript introspection, including integrating [@halfnelson](https://github.com/halfnelson)'s [svelte2tsx](https://github.com/sveltejs/language-tools/tree/master/packages/svelte2tsx#svelte2tsx) which powers understanding the props on components in your codebase.
## Adding TypeScript to an existing project
Before getting started, add the dependencies:
```bash
npm install --save-dev @tsconfig/svelte typescript svelte-preprocess svelte-check
```
### 1. Compiling TypeScript
You first need to set up [`svelte-preprocess`](https://github.com/sveltejs/svelte-preprocess#svelte-preprocess), which passes the contents of your `<script lang="ts">` blocks through the TypeScript compiler.
In a Rollup project, that would look like this — note that we also need to install `@rollup/plugin-typescript` so that Rollup can handle `.ts` files:
```diff
+ import autoPreprocess from 'svelte-preprocess';
+ import typescript from '@rollup/plugin-typescript';
export default {
...,
plugins: [
svelte({
+ preprocess: autoPreprocess()
}),
+ typescript({ sourceMap: !production })
]
}
```
[Full instructions for other environments here](https://github.com/sveltejs/svelte-preprocess#usage).
To configure TypeScript, you will need to create a `tsconfig.json` in the root of your project:
```json
{
"extends": "@tsconfig/svelte/tsconfig.json",
"include": ["src/**/*", "src/node_modules"],
"exclude": ["node_modules/*", "__sapper__/*", "public/*"],
}
```
Your `include`/`exclude` may differ per project — these are defaults that should work across most Svelte projects.
### 2. Editor Support
Any editor [using an LSP](https://langserver.org/#implementations-client) can be supported. The [VS Code](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode) extension has been our primary focus, but there is work in progress [on Atom](https://github.com/sveltejs/language-tools/pull/160), and Vim via [coc-svelte](https://github.com/coc-extensions/coc-svelte) has been updated with the latest LSP.
These editor extensions will improve your coding experience even if you only use JavaScript. The editor won't offer errors, but it will offer inference and refactoring tools. You can [add `// @ts-check`](https://www.staging-typescript.org/docs/handbook/intro-to-js-ts.html) to the top of a `<script>` tag using JavaScript to get better error messages with no infra changes.
To switch a `<script>` to use TypeScript, use `<script lang="ts">` and that should be it. Hopefully you won't be seeing an ocean of red squiggles.
### 3. CI Checks
Having red squiggles is great, well, kinda. On the long run though, you want to be able to verify that there are no errors in your code. To verify your project is error free, you can use the CLI tool [`svelte-check`](https://www.npmjs.com/package/svelte-check). It acts like an editor asking for errors against all of your `.svelte` files.
You can add the dependency to your project and then add it to CI.
```bash
npx svelte-check
Loading svelte-check in workspace: /Users/ortatherox/dev/svelte/example-app
Getting Svelte diagnostics...
====================================
/Users/ortatherox/dev/svelte/example-app/src/App.svelte:3:2
Error: Type '123' is not assignable to type 'string'. (ts)
====================================
svelte-check found 1 error
error Command failed with exit code 1.
```
## What about TypeScript in Sapper projects?
TypeScript support was added to Sapper in 0.28, so if you're using an older version be sure to [upgrade](https://sapper.svelte.dev/migrating#0_27_to_0_28).
## How can I contribute?
We're so glad you asked. The work is happening in the [sveltejs/language-tools](https://github.com/sveltejs/language-tools) repo and in the [#language-tools](https://discord.gg/enV6v8K) channel in the Svelte Discord. If you'd like to report issues, submit fixes, or help out with extensions for new editors and so on, that's where you can find us. See you there!

@ -1,85 +0,0 @@
---
title: "What's new in Svelte: October 2020"
description: New object methods, in-depth learning resources and tons of integration examples!
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Welcome to the first edition of our "What's new in Svelte" series! We'll try to make this a monthly blog post in which you'll find out about new features, bug fixes, and a showcase of Svelte projects from around the community.
## New features
1. `use:obj.method` allows functions defined within objects to be used within actions ([Example](https://svelte.dev/repl/c305722adb4a4545b27b198ea8ff9bde?version=3.27.0), **3.26.0**, warning removed in **3.27.0**)
2. `_` is now supported as a "numerical separator", similar to a `.` or `,` ([Example](https://svelte.dev/repl/844c39e91d1248649fe54af839fab570?version=3.26.0), **3.26.0**)
3. `import.meta` now works in template expressions ([Example](https://svelte.dev/repl/9630de41957a4c80a4fce264360a6bc7?version=3.26.0), **3.26.0**)
4. CSS Selectors with `~` and `+` combinators are now supported ([Example](https://svelte.dev/repl/91ad9257d2d1430185a504a18cc60172?version=3.29.0), **3.27.0**, with a compiler fix in **3.29.0**)
5. The `{#key}` block is now available to key arbitrary content on an expression. Whever the expression changes, the contents inside the `{#key}` block will be destroyed and recreated. For an in-depth explanation and to find out how it's implemented, check out the [new blog post](https://lihautan.com/contributing-to-svelte-implement-key-block/) of Svelte Team member Tan Li Hau. ([More info](https://github.com/sveltejs/svelte/issues/1469), **3.29.0**)
6. Slots can now be forwarded through child components! This used to only be possible by adding extra wrapper `<div>`s ([More info](https://github.com/sveltejs/svelte/issues/2079), **3.29.0**)
7. When using TypeScript, you can now type the `createEventDispatcher` method:
```html
<script lang="ts">
import { createEventDispatcher } from 'svelte';
const dispatch = createEventDispatcher<{
/**
* you can also add docs
*/
checked: boolean; // Will translate to `CustomEvent<boolean>`
hello: string;
}>();
// ...
</script>
```
This will make sure that you can invoke dispatch only with the specified event names and its types. The Svelte for VS Code extension was also updated to deal with this new feature. It will provide strong typings for these events as well as autocompletion and hover information.
**New from Sapper!**
Sapper 0.28.9 just came out. The highlights from it include much better support for CSP nonces, asset preload support for exported pages, and error details are now available in the `$page` store on error pages.
In addition, Sapper's CSS handling has been rewritten over the course of recent releases in order to fix existing CSS handling bugs, refactor the CSS handling to occur entirely within a Rollup plugin, and remove the need internally to register CSS in the routing system. Congrats and thank you to the folks working on Sapper for all their solid work!
## Impactful bug fixes
- CSS compilation will no longer remove rules for the `open` attribute on `<details>` elements ([Example](https://svelte.dev/repl/ab4c0c177d1f4fab92f46eb8539cea9a?version=3.26.0), **3.26.0**)
- `prettier-plugin-svelte` will do a better job now at dealing with whitespaces, especially around inline elements. It will also preserve formatting inside `<pre>` tags and will no longer format languages which are not supported by Prettier, like SASS, Pug or Stylus.
## Coming up
- [Svelte Summit](https://sveltesummit.com/), Svelte's second global online conference, is taking place on October 18! Sign up for free to get reminders and talk updates!
For all the features and bugfixes see the CHANGELOG for [Svelte](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md) and [Sapper](https://github.com/sveltejs/sapper/blob/master/CHANGELOG.md).
---
## Svelte Showcase
- [This CustomMenu example](https://svelte.dev/repl/3a33725c3adb4f57b46b597f9dade0c1?version=3.25.0) demos how to replace the OS right-click menu
- [Github Tetris](https://svelte.dev/repl/cc1eaa7c66964fedb5e70e3ecbbaa0e1?version=3.25.1) lets you play a Tetris-like game in a git commit history
- [Who are my representatives?](https://whoaremyrepresentatives.us/) is a website built with Svelte to help US residents get more info on their congressional representatives
- [Pick Palette](https://github.com/bluwy/pick-palette) is a color palette manager made with Svelte!
### In-depth learning:
- [Svelte 3 Up and Running](https://www.amazon.com/dp/B08D6T6BKS/ref=cm_sw_r_tw_dp_x_OQMtFb3GPQCB2) is a new book about building production-ready static web apps with Svelte 3
- [Sapper Tutorial (Crash Course)](https://www.youtube.com/playlist?list=PL4cUxeGkcC9gdr4Qhx83gBBcID-KMe-PQ) walks through the ins-and-outs of Sapper, the Svelte-powered application framework
- [Svelte Society Day France](https://france.sveltesociety.dev/) happened September 27th featuring a wide variety of topics all in French! You can find the full recording [here](https://www.youtube.com/watch?v=aS1TQ155JK4).
### Plug-and-play components:
- [svelte-zoom](https://github.com/vaheqelyan/svelte-zoom) brings "nearly native" pan-and-zoom to images on desktop and mobile
- [svelte-materialify](https://github.com/TheComputerM/svelte-materialify) is a Material component library for Svelte with over 50 components
- [svelte-undoable](https://github.com/macfja/svelte-undoable) makes it easy to introduce undo and redo functionality using `bind:`
- [This Tilt component](https://svelte.dev/repl/7b23ad9d2693424482cd411b0378b55b?version=3.24.1) implements a common UX pattern where the hovered element tilts to follow the mouse
### Lots of examples of how use JS tech came out this month:
- [Sapper with PostCSS and Tailwind](https://codechips.me/sapper-with-postcss-and-tailwind/)
- [PrismJS (Code block syntax highlighting)](https://github.com/phptuts/Svelte-PrismJS)
- [Filepond (Drag-and-drop file upload)](https://github.com/pqina/svelte-filepond)
- [Ionic (UI Components)](https://github.com/Tommertom/svelte-ionic-app)
- [Pell (WYSIWYG Editor)](https://github.com/Demonicious/svelte-pell/)
- [Leaflet (Mapping)](https://github.com/anoram/leaflet-svelte)
**Reminder**: There's a [Svelte integrations repo](https://github.com/sveltejs/integrations) that demonstrates ways to incorporate Svelte into your stack (and vice versa). If you've got questions on how to use a particular piece of tech with Svelte, you may find your answer there... and if you've gotten something to work with Svelte, consider contributing!
For more amazing Svelte projects, check out the [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs)… and be sure to post your own!
## See you next month!
By the way, Svelte now has an [OpenCollective](https://opencollective.com/svelte)! All contributions and all expenses are published in our transparent public ledger. Learn who is donating, how much, where that money is going, submit expenses, get reimbursed and more!

@ -1,46 +0,0 @@
---
title: "What's new in Svelte: November 2020"
description: Slot forwarding fixes, SvelteKit for faster local development, and more from Svelte Summit
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Welcome back to the "What's new in Svelte" series! This month, we're covering new features & bug fixes, last month's Svelte Summit and some stand-out sites and libraries...
## New features & impactful bug fixes
1. Destructuring Promises now works as expected by using the `{#await}` syntax
(**3.29.3**, [Example](https://svelte.dev/repl/3fd4e2cecfa14d629961478f1dac2445?version=3.29.3))
2. Slot forwarding (released in 3.29.0) should no longer hang during compilation (**3.29.3**, [Example](https://svelte.dev/repl/29959e70103f4868a6525c0734934936?version=3.29.3))
3. Better typings for the `get` function in `svelte/store` and on lifecycle hooks (**3.29.1**)
**What's going on in Sapper?**
Sapper got some new types in its `preload` function, which will make typing easier if you are using TypeScript. See the [Sapper docs](https://sapper.svelte.dev/docs#Typing_the_function) on how to use them. There also were fixes to `preload` links in exported sites. Route layouts got a few fixes too - including ensuring CSS is applied to nested route layouts. You can also better organize your files now that extensions with multiple dots are supported. (**0.28.10**)
For all the features and bugfixes see the CHANGELOGs for [Svelte](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md) and [Sapper](https://github.com/sveltejs/sapper/blob/master/CHANGELOG.md).
## [Svelte Summit](https://sveltesummit.com/) was Svelte-tacular!
- Rich Harris demoed the possible future of Svelte development in a talk titled "Futuristic Web Development". The not-yet-public project is called SvelteKit (name may change) and will bring a first-class developer experience and more flexibility for build outputs. If you want to get the full sneak-peek, [check out the video](https://www.youtube.com/watch?v=qSfdtmcZ4d0).
- 17 speakers made the best of the conference's virtual format... From floating heads to seamless demos, Svelte developers from every skill level will find something of interest in this year's [YouTube playlist](https://www.youtube.com/playlist?list=PL8bMgX1kyZThM1sbYCoWdTcpiYysJsSeu)
---
## Community Showcase
- [Svelte Lab](https://sveltelab.app/) showcases a variety of components, visualizations and interactions that can be achieved in Svelte. You can click into any component to see its source or edit it, using the site's built-in REPL
- [svelte-electron-boilerplate](https://github.com/hjalmar/svelte-electron-boilerplate) is a fast way to get up and running with a Svelte app built in the desktop javascript framework, Electron
- [React Hooks in Svelte](https://github.com/joshnuss/react-hooks-in-svelte) showcases examples of common React Hooks ported to Svelte.
- [gurlic](https://gurlic.com/) is a social network and internet experiment that is super snappy thanks to Svelte
- [Interference 2020](https://interference2020.org/) visualizes reported foreign interference in the 2020 U.S. elections. You can learn more about how it was built in [YYY's talk at Svelte Summit]()
- [jitsi-svelte](https://github.com/relm-us/jitsi-svelte) lets you easily create your own custom Jitsi client by providing out-of-the-box components built with Svelte
- [Ellx](https://ellx.io/) is part spreadsheet, part notebook and part IDE. It's super smooth thanks to Svelte 😎
- [This New Zealand news site](https://www.nzherald.co.nz/nz/election-2020-latest-results-party-vote-electorate-vote-and-full-data/5CFVO4ENKNQDE3SICRRNPU5GZM/) breaks down the results of the 2020 Parliamentary elections using Svelte
- [Budibase](https://github.com/Budibase/budibase) is a no-code app builder, powered by Svelte
- [Svelt-yjs](https://github.com/relm-us/svelt-yjs) combines the collaborative, local-first technology of Yjs with the power of Svelte to enable multiple users across the internet to stay in sync.
- [tabler-icons-svelte](https://github.com/benflap/tabler-icons-svelte) is a Svelte wrapper for over 850 free MIT-licensed high-quality SVG icons for you to use in your web projects.
## See you next month!
Got an idea for something to add to the Showcase? Want to get involved more with Svelte? We're always looking for maintainers, contributors and fanatics... Check out the [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs) to get involved!

@ -1,103 +0,0 @@
---
title: What's the deal with SvelteKit?
description: We're rethinking how to build Svelte apps. Here's what you need to know
author: Rich Harris
authorURL: https://twitter.com/rich_harris
---
<aside><p>If you <em>didn't</em> attend Svelte Summit, you can catch up on the <a href="https://www.youtube.com/c/SvelteSociety/videos">Svelte Society YouTube page</a></p></aside>
If you attended [Svelte Summit](https://sveltesummit.com/) last month you may have seen my talk, Futuristic Web Development, in which I finally tackled one of the most frequently asked questions about Svelte: when will Sapper reach version 1.0?
The answer: never.
This was slightly tongue-in-cheek — as the talk explains, it's really more of a rewrite of Sapper coupled with a rebrand — but it raised a lot of new questions from the community, and it's time we offered a bit more clarity on what you can expect from Sapper's successor, SvelteKit.
<div class="max">
<figure style="max-width: 960px; margin: 0 auto">
<div style="height: 0; padding: 0 0 57.1% 0; position: relative; margin: 0 auto;">
<iframe style="position: absolute; width: 100%; height: 100%; left: 0; top: 0; margin: 0;" src="https://www.youtube-nocookie.com/embed/qSfdtmcZ4d0" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
</div>
<figcaption>'Futuristic Web Development' from <a href="https://sveltesummit.com/">Svelte Summit</a></figcaption>
</figure>
</div>
## What's Sapper?
[Sapper](https://sapper.svelte.dev) is an *app framework* (or 'metaframework') built on top of Svelte (which is a *component* framework). Its job is to make it easy to build Svelte apps with all the modern best practices like server-side rendering (SSR) and code-splitting, and to provide a project structure that makes development productive and fun. It uses *filesystem-based routing* (as popularised by [Next](https://nextjs.org/) and adopted by many other frameworks, albeit with some enhancements) — your project's file structure mirrors the structure of the app itself.
While the Svelte homepage and documentation encourages you to [degit](https://github.com/Rich-Harris/degit) the [sveltejs/template](https://github.com/sveltejs/template) repo to start building an app, Sapper has long been our recommended way to build apps; this very blog post is (at the time of writing!) rendered with Sapper.
## Why are we migrating to something new?
Firstly, the distinction between [sveltejs/template](https://github.com/sveltejs/template) and [sveltejs/sapper-template](https://github.com/sveltejs/sapper-template) is confusing, particularly to newcomers to Svelte. Having a single recommended way to start building apps with Svelte will bring enormous benefits: we simplify onboarding, reduce the maintenance and support burden, and can potentially begin to explore the new possibilities that are unlocked by having a predictable project structure. (This last part is deliberately vague because it will take time to fully understand what those possibilities are.)
Aside from all that, we've been tempted by the thought of rewriting Sapper for a while. This is partly because the codebase has become a little unkempt over the years ([Sapper started in 2017](/blog/sapper-towards-the-ideal-web-app-framework)), but mostly because the web has changed a lot recently, and it's time to rethink some of our foundational assumptions.
## How is this new thing different?
The first of those foundational assumptions is that you need to use a module bundler like [webpack](https://webpack.js.org/) or [Rollup](https://rollupjs.org/) to build apps. These tools trace the dependency graph of your application, analysing and transforming code along the way (turning Svelte components to JS modules, for example), in order to create bundles of code that can run anywhere. As the original creator of Rollup, I can attest that it is a surprisingly complex problem with fiendish edge cases.
You certainly needed a bundler several years ago, because browsers didn't natively support the `import` keyword, but it's much less true today. Right now, we're seeing the rise of the *unbundled development* workflow, which is radically simpler: instead of eagerly bundling your app, a dev server can serve modules (converted to JavaScript, if necessary) *on-demand*, meaning startup is essentially instantaneous however large your app becomes.
[Snowpack](https://www.snowpack.dev/) is at the vanguard of this movement, and it's what powers SvelteKit. It's astonishingly fast, and has a beautiful development experience (hot module reloading, error overlays and so on), and we've been working closely with the Snowpack team on features like SSR. The hot module reloading is particularly revelatory if you're used to using Sapper with Rollup (which has never had first-class HMR support owing to its architecture, which prioritises the most efficient output).
That's not to say we're abandoning bundlers altogether. It's still essential to optimise your app for production, and SvelteKit uses Rollup to make your apps as fast and lean as they possibly can be (which includes things like extracting styles into static `.css` files).
The other foundational assumption is that a server-rendered app needs, well, a server. Sapper effectively has two modes — `sapper build`, which creates a standalone app that has to run on a Node server, and `sapper export` which bakes your app out as a collection of static files suitable for hosting on services like GitHub Pages.
Static files can go pretty much anywhere, but running a Node server (and monitoring/scaling it etc) is less straightforward. Nowadays we're witnessing a shift towards *serverless platforms*, in which you as the app author don't need to think about the server your code is running on, with all the attendant complexity. You can get Sapper apps running on serverless platforms, thanks to things like [vercel-sapper](https://github.com/thgh/vercel-sapper), but it's certainly not what you'd call idiomatic.
<aside><p>It'll still be possible to create both Node apps and fully pre-rendered (aka exported) sites</a></p></aside>
SvelteKit fully embraces the serverless paradigm, and will launch with support for all the major serverless providers, with an 'adapter' API for targeting any platforms that we don't officially cater to. In addition, we'll be able to do partial pre-rendering, which means that static pages can be generated at build time but dynamic ones get rendered on-demand.
## When can I start using it?
If you're feeling brave, you can start right now:
```bash
npm init svelte@next
```
This will scaffold a new project and install the `@sveltejs/kit` CLI, which provides the tools for developing and building an app.
We don't recommend it though! There are no docs, and we won't be able to offer any form of support. It's also likely to break often.
The work is being done in a private monorepo while we're still in exploration mode. Our plan is to get a public beta ready and announce it here once we've closed a few issues — the repo itself will remain private at that time, but we'll create a place to collect feedback from the YOLO crowd. After that, we'll work towards a 1.0 release which will involve opening the repo up.
I'm not going to make any firm promises about timings, because I don't like to break promises. But I *think* we're talking about weeks rather than months.
## What if I don't want to use SvelteKit?
You won't have to — it will always be possible to use Svelte as a standalone package or via a bundler integration like [rollup-plugin-svelte](https://github.com/sveltejs/rollup-plugin-svelte). We think it's essential that you can bend Svelte to fit your workflow, however esoteric, and use third-party app frameworks like [Elder.js](https://github.com/Elderjs/elderjs), [Routify](https://routify.dev/), [Plenti](https://plenti.co/), [Crown](https://crownframework.com/), [JungleJS](https://www.junglejs.org/) and others.
## TypeScript?
Don't worry, we won't launch without full TypeScript support.
## How can I migrate my existing Sapper apps?
For the most part, it should be relatively straightforward to migrate a Sapper codebase.
There are some unavoidable changes (being able to run on serverless platforms means we need to replace custom `server.js` files and `(req, res) => {...}` functions with more portable equivalents), and we're taking the opportunity to fix a few design flaws, but on the whole a SvelteKit app will feel very familiar to Sapper users.
Detailed migration guides will accompany the 1.0 launch.
## How can I contribute?
Keep your eyes peeled for announcements about when we'll launch the public beta and open up the repo. (Also, blog post TODO but I would be remiss if I didn't mention that we now have an [OpenCollective](https://opencollective.com/svelte) where you can contribute financially to the project if it's been valuable to you. Many, many thanks to those of you who already have.)
## Where can I learn more?
Follow [@sveltejs](https://twitter.com/sveltejs) and [@SvelteSociety](https://twitter.com/SvelteSociety) on Twitter, and visit [svelte.dev/chat](https://svelte.dev/chat). You should also subscribe to [Svelte Radio](https://www.svelteradio.com/), where Kevin and his co-hosts will grill me about this project on an upcoming episode (and between now and next week when we record it, [reply to this Twitter thread](https://twitter.com/Rich_Harris/status/1323376048571121665) with your additional questions).

@ -1,71 +0,0 @@
---
title: "What's new in Svelte: December 2020"
description: Better tooling, export maps and improvements to slots and context
author: Daniel Sandoval
authorURL: https://desandoval.net
---
It's the last "What's new in Svelte" of the year and there's lots to celebrate! This month's coverage includes updates from `rollup-plugin-svelte`, `Sapper` and `SvelteKit` and a bunch of showcases from the Svelte community!
## New features & impactful bug fixes
1. `$$props`, `$$restProps`, and `$$slots` are all now supported in custom web components (**3.29.5**, [Example](https://svelte.dev/repl/ad8e6f39cd20403dacd1be84d71e498d?version=3.29.5)) and `slot` components now support spread props: `<slot {...foo} />` (**3.30.0**)
2. A new `hasContext` lifecycle function makes it easy to check whether a `key` has been set in the context of a parent component (**3.30.0** & **3.30.1**, [Docs](https://svelte.dev/docs#run-time-svelte-hascontext))
3. There is now a new `SvelteComponentTyped` class which makes it easier to add strongly typed components that extend base Svelte components. Component library and framework authors rejoice! An example: `export class YourComponent extends SvelteComponentTyped<{aProp: boolean}, {click: MouseEvent}, {default: {aSlot: string}}> {}` (**3.31.0**, [RFC](https://github.com/sveltejs/rfcs/pull/37))
4. Transitions within `{:else}` blocks should now complete successfully (**3.29.5**, [Example](https://svelte.dev/repl/49cef205e5da459594ef2eafcbd41593?version=3.29.5))
5. Svelte now includes an export map, which explicitly states which files can be imported from its npm package (**3.29.5** with some fixes in **3.29.6**, **3.29.7** and **3.30.0**)
6. `rollup-plugin-svelte` had a new [7.0.0 release](https://github.com/sveltejs/rollup-plugin-svelte/blob/master/CHANGELOG.md). The biggest change is that the `css` option was removed. Users who were using that option should add another plugin like `rollup-plugin-css-only` as demonstrated [in the template](https://github.com/sveltejs/template/blob/5b1135c286f7a649daa99825a077586655051649/rollup.config.js#L48)
## What's going on in Sapper?
Lots of new TypeScript definition improvements to make editing Sapper apps even easier! CSS for dynamic imports also should now work in `client.js` files. (Unreleased)
## What's the deal with SvelteKit?
We're glad you asked! If you didn't catch Rich's blog post from early last month, [you can find it here](https://svelte.dev/blog/whats-the-deal-with-sveltekit)!
For all the features and bugfixes see the CHANGELOGs for [Svelte](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md) and [Sapper](https://github.com/sveltejs/sapper/blob/master/CHANGELOG.md).
---
## Community Showcase
**Apps & Sites**
- [narration.studio](https://narration.studio/) (Chrome Only) is an automatic in-browser audio recording & editing platform for voice over narration.
- [Vippet](https://vippet.netlify.app/) is a video recording and editing tool for the browser.
- [Pattern Monster](https://pattern.monster/) is a simple online pattern generator to create repeatable SVG patterns.
- [Plant-based diets](https://planetbaseddiets.panda.org/) is a website from the World Wildlife Foundation (WWF) built with Svelte.
- [johnells.se](https://www.johnells.se/) is a Swedish fashion e-commerce site, built with [Crown](https://crownframework.com/) - a Svelte-powered framework.
- [sentence-length](https://sentence-length.netlify.app/) is a learning and analysis tool to show how some authors play with different lengths, while others stick with one.
- [svelte-presenter](https://github.com/stephane-vanraes/svelte-presenter) lets you quickly make good looking presentations using Svelte and mdsvex.
**Demos**
- [u/loopcake got SSR working in Java Spring Boot](https://www.reddit.com/r/sveltejs/comments/jkh5up/svelte_ssr_but_its_java_spring_boot_and_its_native/) for all the Java shops out there looking to render Svelte server-side.
- [svelte-liquid-swipe](https://github.com/tncrazvan/svelte-liquid-swipe) shows off a fancy interaction pattern using svg paths.
- [Crossfade Link Animation](https://svelte.dev/repl/7f68e148caf04b2787bb6f296208f870?version=3.29.7) demonstrates how to animate between navigation links using a crossfade (made by Blu, from the Discord community)
- [Clip-Path Transitions](https://svelte.dev/repl/b5ad281ae8024b629b545c70c9e8764d?version=3.29.7) showcases how to use clip paths and custom transitions to create magical in-and-out transitions (made by Faber, from the Discord community)
**Learning Resources**
- [lihautan](https://www.youtube.com/channel/UCbmC3HP3FaAFdcZkui8YoMQ/featured) has been making easy-to-follow videos to share his in-depth knowledge of Svelte.
- [Lessons From Building a Static Site Generator](https://nicholasreese.com/lessons-from-building-a-static-site-generator/) shares the backstory and thinking behind Elder.js - and the design decision made along the way.
- [Svelte Tutorial and Projects Course ](https://www.udemy.com/course/svelte-tutorial-and-projects-course/) is a udemy course by John Smilga where students learn Svelte.js by building interesting projects.
- [Building Pastebin on IPFS - with FastAPI, Svelte, and IPFS](https://amalshaji.wtf/building-pastebin-on-ipfs-with-fastapi-svelte-and-ipfs) explains how to make a distributed pastebin-like application.
**Components, Libraries & Tools**
- [svelte-crossword](https://russellgoldenberg.github.io/svelte-crossword/) is a customizable crossword puzzle component for Svelte.
- [svelte-cloudinary](https://github.com/cupcakearmy/svelte-cloudinary) makes it easy to integrate Cloudinary with Svelte (including Typescript and SSR support)
- [Svelte Nova](https://extensions.panic.com/extensions/sb.lao/sb.lao.svelte-nova/) extends the new Nova editor to support Svelte
- [saos](https://github.com/shiryel/saos) is a small svelte component to animate your elements on scroll.
- [Svelte-nStore](https://github.com/lacikawiz/svelte-nStore) is a general purpose store replacement that fulfills the Svelte store contract and adds getter and calculation features.
- [svelte-slimscroll](https://github.com/MelihAltintas/svelte-slimscroll) is a Svelte Action that transforms any div into a scrollable area with a nice scrollbar.
- [svelte-typewriter](https://github.com/henriquehbr/svelte-typewriter) is a simple and reusable typewriter effect for your Svelte applications
- [svelte-store-router](https://github.com/zyxd/svelte-store-router) is a store-based router for Svelte that suggests that routing is just another global state and History API changes are just an optional side-effects of this state.
- [Routify](https://routify.dev/blog/routify-2-released) just released version 2 of its Svelte router.
- [svelte-error-boundary](https://www.npmjs.com/package/@crownframework/svelte-error-boundary) provides a simple error boundary component for Svelte that can be can be used with both DOM and SSR targets.
- [svelte2dts](https://www.npmjs.com/package/svelte2dts) generates d.ts files from svelte files, creating truly shareable and well typed components.
## See you next month!
Got an idea for something to add to the Showcase? Want to get involved more with Svelte? We're always looking for maintainers, contributors and fanatics... Check out the [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs) to get involved!
That's all for the year, folks! See you in January 😎

@ -1,86 +0,0 @@
---
title: "What's new in Svelte: January 2021"
description: A Svelte-packed showcase to kick-off the new year!
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Happy new year from Svelte! In the last month we made progress on Sapper's upcoming release, fine-tuned our `SvelteComponent` typings, and have seen some amazing apps, sites, and libraries coming out in the showcase.
## What's changed in Svelte?
A new minor release replaces the `SvelteComponent` class with a `SvelteComponentTyped` class. This renaming should help with backwards compatibility. We've updated [last month's blog post](https://svelte.dev/blog/whats-new-in-svelte-december-2020) to avoid any confusion with the name change.
If you're using `SvelteComponent` or the new `SvelteComponentTyped` in your project or library, let us know what you're using it for and we'll add it to the showcase!
## What's going on in Sapper?
More quality of life features are landing in the upcoming release every day. `0.29.0` will include new TypeScript definitions, fixes to scroll tracking and prefetching behavior, and improvements to the runtime router to support encoded query parameters.
If you're upgrading from 0.28.x, check out [the migration guide](https://sapper.svelte.dev/migrating/#0_28_to_0_29) for steps on updating to Sapper 0.29.
## Is SvelteKit ready yet?
To avoid too much churn during development, SvelteKit is still being worked on in a private repo. There will be an announcement on the Discord, blog and Twitter when it's ready for a larger group of users and contributors.
In the meantime, you can explore the current build by running `npm init svelte@next` from your command line.
As cautioned in _[What's the deal with SvelteKit?](https://svelte.dev/blog/whats-the-deal-with-sveltekit)_, there are no docs or support available yet... So use at your own risk / for your own enjoyment!
---
## Community Showcase
**Apps & Sites**
- [manitu.me](https://manitu.me/) is a background sound / pomodoro timer for focus and relaxation
- [Answer Socrates](https://answersocrates.com/) helps you find trending questions on the internet so that you can write the most relevant blog post, tweet, or billboard
- [multris](https://multris.s1h.org/) is a multiplayer Tetris game. You can read about its development [here](https://blog.s1h.org/svelte-multiplayer-game/)
- [weather-ab](https://github.com/ganochenkodg/weather-ab) compares the archive of weather in different cities of the world. Indispensable for people thinking about migration
- [Game Nibs](https://gamenibs.com/) is a platform for gamers to find and share concise bite-sized bits of gaming advice, tips, tricks, screenshots, builds, and much more
- [Ora](https://github.com/cupcakearmy/ora) is an open source website tracking and limiting tool for Chrome and Firefox
- [vscode-dms](https://github.com/techsyndicate/vscode-dms) is a group direct messaging chat app for VSCode
- [Zero.2](https://zero.oleksandrdemian.tech/) is a math-based challenge game where you try to get to zero as quickly as possible
- [Octave Compass](https://octavecompass.com/2741) is a chord table and scale explorer for many popular musical scales
- [Infinite Walking Bass Generator 2](https://github.com/elialbert/infinitewalkingbass2) is an online music player that generates a unique walking bass line
- [ListenAddict](https://www.listenaddict.com/) is a site that notifies you whenever a person has a new talk/interview on podcast
**Demos, Libraries & Components**
- [svelte-tiny-virtual-list](https://github.com/Skayo/svelte-tiny-virtual-list) speeds up long lists by only rendering visible items
- [svelte-query](https://github.com/TanStack/svelte-query) is a collection of helpful hooks for managing, caching and syncing asynchronous and remote data
- [svelte-previous](https://github.com/bryanmylee/svelte-previous) is a svelte store to remember previous values - helpful for transitions or a quick undo stack
- [Let's Build a Confetti Cannon](https://varun.ca/confetti/) explains how to build a particle system and integrate a Canvas based animation into a larger application
- [svelte-micro](https://github.com/ayndqy/svelte-micro) is a one-component router
- [svelte-standalone-router](https://github.com/hjalmar/svelte-standalone-router) is a standalone router with an API based on [standalone-router](https://github.com/hjalmar/standalone-router)
- [svelte-datepicker](https://github.com/beyonk-adventures/svelte-datepicker) is a datepicker component with variations for time selection, date ranges and responsive themes
- [svelte-slimscroll](https://github.com/MelihAltintas/svelte-slimscroll) is a action for Svelte.js, which can transforms any div into a scrollable area with a nice scrollbar.
- [Svelte Zoomable](https://svelte.dev/repl/58dfe87756ee4db897c281b52fdef7b7?version=3.31.0) is a custom transition with a nice zoom effect
**Have a component you'd like to share?** Check out the [Components](https://sveltesociety.dev/components) page on the Svelte Society site. You can contribute by making [a PR to this file](https://github.com/svelte-society/sveltesociety.dev/blob/master/src/pages/components/components.json).
**Learning Resources**
- [Using Svelte to create a scroll video effect](https://blog.koenvangilst.nl/tutorial-svelte-scroll-video/) showcases how the `bind` command can be used to create a cool scroll video effect with very little code
- [How to make a flappybird game in svelte and typescript](https://www.youtube.com/watch?v=nhrYBoVI8pQ) is a video tutorial including docs and code for reference
- [Accessible Svelte Transition](https://www.youtube.com/watch?v=QK_QuRL7nSo&feature=youtu.be) walks through `prefers-reduced-motion` to make svelte transitions more accessible
- [Svelte's module scripts explained](https://codechips.me/svelte-module-scripts-explained/) is a great introduction to the module context, a common Sapper pattern
- [Awesome Svelte](https://github.com/TheComputerM/awesome-svelte#readme) is a curated list of Svelte resources
- [.NET Core and Svelte](https://dev.to/cainux/net-core-and-svelte-f8o) explains how to get Svelte up and running with .NET Core
- [A la découverte de Svelte JS](https://www.youtube.com/watch?v=SLpx1Y8e1ek&list=PLff5I1miao9ZEUhpqkrOx7k8RGAZt-nm9) is a svelte tutorial series in French!
- [Svelte for React Developers](https://soshace.com/svelte-for-react-developers/) explains Svelte's core concepts to folks who are used to React
- [Building a Svelte Static Website with Smooth Page Transitions](https://www.youtube.com/watch?v=dvPfmcGtmrI&feature=emb_title) shows how to build a static website with Svelte and add smooth page transitions using Three.js and GSAP.
- [Using Apollo Client in Sapper](https://bjornlu.com/blog/using-apollo-client-in-sapper/) explains the "simplest" solutions to integrate the Apollo query client into Sapper
- [Reactive web apps with Crystal + Svelte](https://www.youtube.com/watch?v=i1xjLd6z7BU) explores how to build full-stack, server-rendered Svelte apps with a [Crystal](https://crystal-lang.org) backend
**Related Projects**
- [Snowpack's v3 release candidate](https://www.snowpack.dev/posts/2020-12-03-snowpack-3-release-candidate) is out now in preparation for a January 6 release date. Check out the [Getting Started with Svelte](https://www.snowpack.dev/tutorials/svelte) for more info on how to use Snowpack.
- [Uppy](https://uppy.io/blog/2020/12/1.24/), the open source file uploader, announced Svelte support in its new version 1.24
## See you next month!
Want to add your work to the Showcase? Want to contribute to Svelte? Check out the [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs) to get involved!

@ -1,86 +0,0 @@
---
title: "What's new in Svelte: February 2021"
description: Integrations and improvements at lightning speed...
author: Daniel Sandoval
authorURL: https://desandoval.net
---
With the shortest month of the year coming up, Svelte maintainers and community members alike have been busy this last month from big changes in `svelte-loader`, `prettier-plugin-svelte`, `rollup-plugin-svelte`, and `language-tools` to steady progress in Sapper and `svelte-preprocess`. Meanwhile, lots of folks have been busy integrating Svelte with other popular frameworks.
## New compiler features
- Aria roles from the [WAI-ARIA Graphics Module](https://www.w3.org/TR/graphics-aria-1.0/#role_definitions) are now recognized as valid aria roles in Svelte components (**3.31.1**)
- Compiler warnings for the common React attributes, `className` and `htmlFor`, now make it easier to port React components to Svelte (**3.31.1**)
Have a suggestion for a compiler feature or want to help implement new features/bug fixes? Check out the ["triage: good first issue" tag for Svelte](https://github.com/sveltejs/svelte/issues?q=is%3Aopen+is%3Aissue+label%3A%22triage%3A+good+first+issue%22)
## New bits in language-tools
- User disabled auto import suggestions no longer show in VS Code (**103.0.0**)
- Renaming a variable is now safer with smart additions of a prefix/suffix to renamed variables (**104.0.0**)
- Semantic (token) highlighting for TypeScript users lets theme makers apply semantic styling in their themes, if they support it (**104.0.0**)
- "Extract Component" has been added to the context menu - allowing you to extract components out of files without having to open the command window to type "Svelte: Extract Component" (**104.0.0**)
- The VS Code extension now listens to JavaScript/TypeScript file changes - you no longer need to save the files for the changes to be noticed (**104.1.0**)
For the complete list of changes, check out the language-tools [Releases page](https://github.com/sveltejs/language-tools/releases).
A great way to try the language tools is to download the [Svelte Extension for VSCode](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode). This extension provides syntax highlighting and rich intellisense for Svelte components in VS Code, using the svelte language server. Check your editor's extension sources to see if there's a Svelte plugin for your IDE or build your own (see [coc-svelte](https://github.com/coc-extensions/coc-svelte) for example)!
## Big improvements across the Svelte ecosystem
- [svelte-loader](https://github.com/sveltejs/svelte-loader) released a major version, 3.0.0 - featuring Webpack 5 and Node 14 support, better hot reloading, and new `compilerOptions` to match `rollup-plugin-svelte`. Breaking changes include dropping Svelte 2 and Node 8 support. [More info in the changelog](https://github.com/sveltejs/svelte-loader/blob/master/CHANGELOG.md)
- [rollup-plugin-svelte](https://github.com/sveltejs/rollup-plugin-svelte) is now at version 7.x - with support for relative filenames, better handling of sourcemaps, and consistent `compilerOptions`. Be sure to [checkout the changelog](https://github.com/sveltejs/rollup-plugin-svelte/blob/master/CHANGELOG.md) for breaking changes when upgrading
- [svelte-preprocess](https://github.com/sveltejs/svelte-preprocess) iterated through some 4.6.x releases this month to improve postcss and scss handling and fix sourcemap transformation for typescript users. [More info in the changelog](https://github.com/sveltejs/svelte-preprocess/blob/main/CHANGELOG.md)
- [Sapper](https://github.com/sveltejs/sapper) got some improvements in scroll tracking and handling encoding query parameters. Dynamic imports also now work as expected in browsers that don't support ES modules. These changes from 0.29.0 and a step-by-step migration guide can be found [in the changelog](https://github.com/sveltejs/sapper/blob/master/CHANGELOG.md)
- [prettier-plugin-svelte](https://github.com/sveltejs/prettier-plugin-svelte) version 2 was released. It received an overhaul and comes with a rewrite of the HTML formatting. The output is now much more in line with how standard Prettier formats HTML. Better defaults for `svelteBracketNewLine` and `options-scripts-markup-styles` should now match how the majority of users like to order the code blocks. Additionally, Prettier's `htmlWhitespaceSensitivity` setting is now supported. [More info in the changelog](https://github.com/sveltejs/prettier-plugin-svelte/blob/master/CHANGELOG.md)
New changes to the Svelte Society website include [a new cheat sheet](https://sveltesociety.dev/cheatsheet) for easy access to useful code patterns and some smaller visual fixes across the site. **Want to help make the Svelte Society website ready for prime time**? [Checkout the GitHub repo](https://github.com/svelte-society/sveltesociety.dev) to get started!
---
## Community Showcase
**Apps & Sites**
- [The official German vaccination dashboard](https://impfdashboard.de/) tracks the current COVID vaccine rollout and features some well-done dataviz.
- [La neuva era de la educatión conectada](https://elfuturoesapasionante.vodafone.es/especiales/educacion-conectada/) is a Vodaphone site that highlights the ways that technology and COVID-19 has changed the education landscape
- [sho.rest](https://github.com/Melonai/shorest) is a self-hostable url shortener
- [night.fm](https://night.fm/) is a cyberpunk-themed radio station
**Demos, Libraries & Components**
- [Svelte Reactive Debugger](https://addons.mozilla.org/en-US/firefox/addon/svelte-reactive-debugger/) is a way to monitor Svelte reactive statements in Firefox devtools
- [svelte-actions](https://github.com/sw-yx/svelte-actions) is a set of prototype Svelte actions for inclusion into official actions in future. [See RFC](https://github.com/sveltejs/rfcs/pull/24) and [Discuss High Level Policy](https://github.com/sw-yx/svelte-actions/issues/7).
- [This css grid gallery](https://svelte.dev/repl/3a1b7fae13b242fe9cd4a4f7aa092fa4?version=3.31.2) made by @joja (in the Svelte Discord) features grid transitions based on a user's mouse position
- [Patchcab](https://github.com/spectrome/patchcab) is a modular Eurorack style synthesizer made with Web Audio.
- [svelte-knob](https://github.com/MelihAltintas/svelte-knob) is a knob control to help with speedometer-style visualization
- [descent-ripple](https://github.com/micha-lmxt/descent-ripple) is a highly customizable javascript ripple animation for buttons
- [makeItSnow](https://github.com/florianlouvet/make-it-snow/blob/main/makeItSnowAction.js) is a Svelte action made by @MrPoule (in the Svelte Discord) that can be used to add ❄snow❄ to any component ([Demo](https://svelte.dev/repl/de5223beb45540a5a11c9bd7b318304f?version=3.31.2))
- [svelte-video-player](https://github.com/meigo/svelte-video-player) is a customizable `VideoPlayer` component
- [svelte-readonly](https://github.com/Crisfole/svelte-readonly) is a very small store that exposes only a readable interface.
**New Integrations & Starters**
- [svelte-derver-starter](https://github.com/AlexxNB/svelte-derver-starter) is a starter for baking fullstack application with the client based on Svelte and server side powered by Derver.
- [eleventy-plugin-embed-svelte](https://github.com/shalomscott/eleventy-plugin-embed-svelte) makes it easy to embed Svelte components into an 11ty site.
- [svelte-tailwind-extension-boilerplate](https://github.com/kyrelldixon/svelte-tailwind-extension-boilerplate) is a good foundation for a Chrome extension using either JavaScript or TypeScript, Svelte for the frontend, Tailwind CSS for styling, Jest for testing, and Rollup as the build system.
- [snowpack-ui](https://github.com/rajasegar/snowpack-ui) lets you run & manage Snowpack projects from the browser instead of the terminal
- [Svelte for Appwrite](https://dev.to/torstendittmann/svelte-for-appwrite-4fkg) explains how to integrate with Appwrite, a self-hosted Firebase alternative [Github Repo](https://github.com/appwrite/sdk-for-svelte)
- [here-maps-svelte](https://github.com/peopledrivemecrazy/here-maps-svelte) makes it easy to include HERE maps in a Svelte app
- [p5-svelte](https://github.com/tonyketcham/p5-svelte) is an absolutely dead simple way of tossing the creative coding/sketching tool, p5, into a project
- [svelte-windicss-preprocess](https://github.com/voorjaar/svelte-windicss-preprocess) is a Svelte preprocessor to compile tailwindcss at build time based on windicss compiler
- [MitzaCoder/svelte-boilerplate](https://github.com/MitzaCoder/svelte-boilerplate) features configurations for Typescript, TailwindCSS, IE11 compatibility (with Babel) and lazy loaded modules.
**Want to share your Svelte Component with the world?** Head over to the [Components](https://sveltesociety.dev/components) page on the Svelte Society site. You can contribute by making [a PR to this file](https://github.com/svelte-society/sveltesociety.dev/blob/master/src/pages/components/components.json).
**Learning Resources**
- [lihautan's Svelte Actions Playlist](https://www.youtube.com/watch?v=ciaMT_MswzE&list=PLoKaNN3BjQX3Gl14MBygFf8buPIw9pAeK) teaches how actions work and how they can help solve common problems when developing Svelte applications
- [One-click Portfolio/Personal blog generator from dev.to API ](https://dev.to/shriji/one-click-portfolio-personal-blog-generator-from-dev-to-api-3apb) walks through creating a Sapper site that also fetches your articles from DEV.to using the API
- [How to Code a VSCode Extension](https://www.youtube.com/watch?v=a5DX5pQ9p5M) features Svelte as a way to render a custom UI within VSCode
- [This YouTube series on Plenti](https://www.youtube.com/watch?v=wyNC7R_VVyQ&list=PLbWvcwWtuDm12y3Hye6oKDwI2gAS0ccHW) walks through the new static site generator in detail
## See you next month!
Want to add your work to the Showcase? Want to contribute to Svelte? Check out the [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs) to get involved!

@ -1,104 +0,0 @@
---
title: "What's new in Svelte: March 2021"
description: Call for Svelte Summit Speakers! Improved SSR, non-HTML5 compilation targets, and ESLint TypeScript support
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Lots to cover this month with releases from across the Svelte ecosystem. Most importantly, Svelte Summit Spring 2021 has an [Open Call for Speakers](https://sessionize.com/svelte-summit-spring-2021). **The deadline is March 14** so if you have an idea for a talk, submit it now!
Let's dive into the news 🐬
## What's new in `sveltejs/svelte`
* SSR store handling has been reworked to subscribe and unsubscribe as in DOM mode. SSR stores should work much more consistently now (**3.31.2**, see [custom stores](https://svelte.dev/examples/custom-stores) and [Server-side component API ](https://svelte.dev/docs#run-time-server-side-component-api))
* Multiple instances of the same action are now allowed on an element (**3.32.0**, [example](https://svelte.dev/repl/01a14375951749dab9579cb6860eccde?version=3.32.0))
* The new `foreign` namespace should make it easier for alternative compile targets (like Svelte Native and SvelteGUI) by disabling certain HTML5-specific behaviour and checks (**3.32.0**, [more info](https://github.com/sveltejs/svelte/pull/5652))
* Support for inline comment sourcemaps in code from preprocessors (**3.32.0**)
* Destructured defaults are now allowed to refer to other variables (**3.33.0**, [example](https://svelte.dev/repl/0ee7227e1b45465b9b47d7a5ae2d1252?version=3.33.0))
* Custom elements will now call `onMount` functions when connecting and clean up when disconnecting (**3.33.0**, checkout [this PR](https://github.com/sveltejs/svelte/pull/4522) for an interesting conversation on how folks are using Svelte with Web Components)
* A `cssHash` option has been added to the compiler options to control the classname used for CSS scoping (**3.34.0**, [docs](https://svelte.dev/docs#compile-time-svelte-compile))
* Continued improvement to Typescript definitions
For a complete list of changes, including bug fixes and links to PRs, check out [the CHANGELOG](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md)
## New from `sveltejs/language-tools`
- For language server clients that don't support `didChangeWatchedFiles`, a fallback file watcher will be used instead
- New highlighting rules for store accessors and element directives (like `bind:` and `class:`)
- HTML tags can now be renamed together
- Mustache tags parsing is now more robust and will provide better intellisense in more situations
Haven't tried the language-tools yet? Check out [Svelte Extension for VSCode](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode) or find a plugin for your favorite IDE!
## Other changes from `sveltejs/*`
- [eslint-plugin-svelte3](https://github.com/sveltejs/eslint-plugin-svelte3) now supports TypeScript as of 3.1.0
- [prettier-plugin-svelte](https://github.com/sveltejs/prettier-plugin-svelte/) released a number of minor versions to address whitespace and comment trimming issues.
- [svelte-preprocess](https://github.com/sveltejs/svelte-preprocess/) bug fixes this month include fixes to postcss transformations and support for both v2 and v3 of `postcss-load-config`
- [sapper](https://github.com/sveltejs/sapper/)'s 0.29.1 release fixes some bad imports in type definitions, updates typings to be compatible with express/polka, and restores hashing of all CSS file names.
---
## Community Showcase
**Apps & Sites**
- [Tracking the Coronavirus](https://www.nytimes.com/interactive/2021/us/new-york-city-new-york-covid-cases.html) from NYTimes is an example of SvelteKit in production
- [Budibase](https://github.com/Budibase/budibase) is an open-source low-code platform, helping developers and IT professionals build, automate, and ship internal tools 50x faster on their own infrastructure.
- [Track the Parcel](https://tracktheparcel.com/) is a one-stop tool for tracking parcel status with all major package shippers.
- [Memo](https://sendmemo.app/features/) is a replacement for email that uses Svelte for modern messaging
- [Userscripts Safari](https://github.com/quoid/userscripts) is an open-source userscript editor for Safari... a native Svelte app for Mac OS!
- [SVGX](https://svgx.app/) is "the desktop SVG asset manager designers and developers wished they had."
- [Armoria](https://azgaar.github.io/Armoria/) is a procedural heraldry generator and editor
- [FictionBoard](https://www.fictionboard.com) is a virtual table top (VTT) platform that just released fillable and responsive character sheets
- [Castles & Crusades Treasure Generator](https://treasure.playaheadgames.com/) is a treasure generator for the table top RPG: Castles and Crusades.
- [NESBit Studio](https://jensa.org/NESBitStudio-web/graphics/spritesheets) is a toolkit to help the development of homebrew NES games
- [ElectroBlocks](https://electroblocks.org/) is an online Arduino IDE with a built-in simulator (Chrome Only)
- [Goblin.life](https://store.steampowered.com/app/552180/GoblinLife/) is a 3D world builder whose UI is built with Svelte
- [farmbox](https://farmbox.ae/) is a UAE-based grocery delivery services
- [heroeswearmasks.fun](https://heroeswearmasks.fun/) is a client-side machine learning tool that determines whether or not you're wearing a mask.
- [weatherify](https://brdtheo-weatherify.netlify.app/) is a very pretty (and [open source](https://github.com/brdtheo/weatherify)) weather app
- [DSN Live](https://dsn-live.netlify.app/#/) lets you monitor connections between NASA/JPL and interplanetary spacecraft missions in real time.
**Demos, Libraries, Tools & Components**
- [spc](https://github.com/khang-nd/spc) is a special characters picker component for the web
- [svelte-injector](https://www.npmjs.com/package/svelte-injector) lets you inject Svelte components in React, Angular, Vue, jQuery, Vanilla JS.
- [Felte](https://felte.dev/) is a form library for Svelte with simple validation reporting.
- [svelte-use-form](https://github.com/noahsalvi/svelte-use-form#readme) is form library that "is easy to use and has 0 boilerplate."
- [Formula](https://formula.svelte.codes/) provides "Zero Configuration Reactive Forms for Svelte."
- [Houdini](https://github.com/AlecAivazis/houdini) is "the disappearing GraphQL client built for Sapper and Sveltekit."
- [svelte-split-pane](https://www.reddit.com/r/sveltejs/comments/leoe33/sveltesplitpane/) is a draggable split pane component
- [svelte-virtualized-auto-sizer](https://github.com/micha-lmxt/svelte-virtualized-auto-sizer) is a high-order component that automatically adjusts the width and height of a single child.
- [svelte-window](https://github.com/micha-lmxt/svelte-window) are components for efficiently rendering large, scrollable lists and tabular data.
- [Svelte Persistent store](https://github.com/MacFJA/svelte-persistent-store) is a Svelte store that keep its value through pages and reloads
- [Svelte Dark](https://marketplace.visualstudio.com/items?itemName=NickScialli.svelte-dark) is a VSCode theme inspired by the svelte.dev REPL
- [Import Cost](https://marketplace.visualstudio.com/items?itemName=wix.vscode-import-cost) has been updated to support Svelte libraries and help developers keep their bundle size under control.
- [Tree-sitter-svelte](https://github.com/Himujjal/tree-sitter-svelte) provides tree-sitter grammar for svelte
- [Svelte Ripple](https://svelte.dev/repl/b73224a0fd4248178e3eab41943d41a9?version=3.31.2) is a Material Design ripple effect that doesn't depend on `@material/ripple` (made by @karakara in the Svelte Discord)
- [Analog SVG Clock](https://svelte.dev/repl/270e83f43e7a48918d8f2d497760904f?version=3.32.1) is a great example of easing functions (made by @tonmcg in the Svelte Discord)
- [Console Log Styler](https://svelte.dev/repl/11f609d0d90746f08da6d3d90bba84fc?version=3.32.0) lets you generate a styled console log using pseudo HTML and CSS (made by @EmNudge in the Svelte Discord)
- [svelte-heroicons](https://github.com/martinse/svelte-heroicons) is a handy wrapper for the Heroicons icon library
- [supabase-ui-svelte](https://github.com/joshnuss/supabase-ui-svelte) are UI components for Supabase authentication
**Have your own Svelte Component to share?** Check out the [Components](https://sveltesociety.dev/components) page on the Svelte Society site. You can contribute by making [a PR to this file](https://github.com/svelte-society/sveltesociety.dev/blob/master/src/pages/components/components.json).
**Learning Resources & Starters**
- [The **unofficial** SvelteKit docs](https://sk-incognito.vercel.app/learn/what-is-sveltekit) were built using SvelteKit and are [open for contributions](https://github.com/GrygrFlzr/kit-docs)
- [📦 Svelte Store](https://www.youtube.com/playlist?list=PLoKaNN3BjQX3fG-XOSwsPHtnV8FUY6lgK) course by lihautan covers the basics of Svelte Stores and best practices.
- [Svelte Events](https://www.youtube.com/watch?v=cbxxbBofjAw&feature=youtu.be) by WebJeda explains how directives like `on:` can be used to listen to DOM events.
- [How to Set Up Protected Routes in Your Svelte Application](https://www.webtips.dev/how-to-set-up-protected-routes-in-your-svelte-application) describes how to authenticate your users to access your routes
- [Using Fauna's streaming feature to build a chat with Svelte](https://dev.to/fauna/using-fauna-s-streaming-feature-to-build-a-chat-with-svelte-1gkd) demonstrates how to setup and configure Fauna to build a real-time chat interface with Svelte
- [Using TakeShape with Sapper](https://www.takeshape.io/articles/using-takeshape-with-sapper/) demonstrates how to connect the TakeShape CMS with Sapper
- [YastPack](https://github.com/rodabt/yastpack) is Yet Another Snowpack-Svelte-TailwindCss-Routify Template Pack
- [S2T2](https://ralphbliu.medium.com/s2t2-snowpack-svelte-tailwindcss-typescript-8928caa5af6c) is a Snowpack + Svelte + TailwindCSS + Typescript template
- [tonyketcham/sapper-tailwind2-template](https://github.com/tonyketcham/sapper-tailwind2-template) is a Sapper Template w/ Tailwind 2.0, TypeScript, ESLint, and Prettier
## See you next month!
Got something to add? Join us on [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs)!

@ -1,67 +0,0 @@
---
title: SvelteKit is in public beta
description: And we'd love to have your feedback
author: Rich Harris
authorURL: https://twitter.com/rich_harris
---
<aside><p>Previously: <a href="/blog/whats-the-deal-with-sveltekit">What's the deal with SvelteKit?</a></p></aside>
It's time. After five months and hundreds of commits, you're finally invited to try out the SvelteKit beta. It's not finished — there are a few known bugs and several missing features — but we're really happy with how it's shaping up and can't wait for you to try it.
Starting a new project is easy:
```bash
# create the project
mkdir my-app
cd my-app
npm init svelte@next
# install dependencies
npm install
# start dev server and open a browser tab
npm run dev -- --open
```
You'll find documentation at [kit.svelte.dev/docs](https://kit.svelte.dev/docs). If you have a [Sapper](https://sapper.svelte.dev) app that you'd like to migrate to SvelteKit, you'll find instructions at [kit.svelte.dev/docs/migrating](https://kit.svelte.dev/docs/migrating).
The source code is available at [github.com/sveltejs/kit](https://github.com/sveltejs/kit). Issues and pull requests are disabled while we finish getting our house in order, but we'll be making it fully open in the near future.
## Wait, what is SvelteKit?
Think of it as [Next](https://nextjs.org/) for Svelte. It's a framework for building apps with Svelte, complete with server-side rendering, routing, code-splitting for JS and CSS, adapters for different serverless platforms and so on.
If you're familiar with [Sapper](https://sapper.svelte.dev), SvelteKit is Sapper's successor.
## From Snowpack to Vite
One thing that might seem surprising after the [announcement video](/blog/whats-the-deal-with-sveltekit), in which I waxed lyrical about [Snowpack](https://www.snowpack.dev/), is that SvelteKit uses [Vite](https://vitejs.dev) under the hood. When we tried Snowpack back when we started thinking about what form SvelteKit should take, it was love at first sight.
Snowpack created an entirely new category of dev tooling. Rather than _bundling_ your app in development, as we've been doing with webpack and Rollup for the last several years, Snowpack is an _unbundled dev server_ that uses the browser's native `import` and does 1:1 transformations of things like Svelte components on the fly. As a result you get quick startup, simple caching and instant hot module reloading. Once you experience this way of working, it will ruin you for anything else.
Vite falls into the same category as Snowpack. While Vite 1 wasn't suitable for SvelteKit — it was Vue-centric (Vite and Vue are both created by [Evan You](https://twitter.com/youyuxi)) and made server-side rendering difficult — Vite 2 is framework-agnostic and designed with SSR at the core. It also has powerful features, like CSS code-splitting, that we previously had to implement ourselves. When we evaluated the two technologies side-by-side we were forced to conclude that Vite is a closer match for SvelteKit's requirements and would give us the best chance to deliver the framework of our imaginations.
We owe a deep debt of gratitude to the Snowpack team, both for the close collaboration earlier in development and for lighting the path that web development will take over the next few years. It's a wonderful tool, and you should absolutely try it out.
## Dogfooding as extreme sport
SvelteKit is very much in beta, but that doesn't mean it hasn't been used in production.
My day job is at the New York Times, where I've spent much of the last twelve months working on our [coronavirus tracker](https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html). It uses a customised version of the workflow that powers the majority of graphics at the Times, which isn't designed for large multi-page projects. When we decided late last year to create pages for each of the ~3,000 counties in the US, we quickly realised we would need to completely rearchitect the project.
Even though it was far from ready, SvelteKit was the only framework that matched our esoteric requirements. (Anyone who has worked in a newsroom and done battle with their CMS will know what I'm talking about.) Today it powers our [county risk pages](https://www.nytimes.com/interactive/2021/us/tom-green-texas-covid-cases.html) and we're in the process of migrating existing pages to the SvelteKit app.
<aside><p>I am eternally grateful for my coworkers' forbearance.</p></aside>
Using unfinished software to build an app that will be seen by millions of people is a risk, and in general I don't recommend it. But it has enabled us to develop the app much faster, and has made the framework itself much stronger than it otherwise would be.
## The road to 1.0
You can see the list of outstanding issues with the 1.0 milestone on our [issue tracker](https://github.com/sveltejs/kit/issues?q=is%3Aopen+is%3Aissue+milestone%3A1.0). Alongside that work, we plan to upgrade the documentation and add more [adapters](https://kit.svelte.dev/docs/adapters).
Most importantly though, we need your feedback to help us make the best possible app framework. Try it out, and let us know which pieces are missing.
Many thanks to everyone who has tried SvelteKit out despite the 'here be dragons' warnings and lack of documentation; your back-channel feedback has been invaluable. In particular, I want to acknowledge the work of [GrygrFlzr](https://github.com/GrygrFlzr), who maintained unofficial docs and a fork that added Windows support when we lacked it; and [dominikg](https://github.com/dominikg) whose work on [Svite](https://github.com/svitejs/svite) laid essential groundwork for SvelteKit's Vite integration. Both have now been welcomed onto the team.

@ -1,73 +0,0 @@
---
title: "What's new in Svelte: April 2021"
description: SvelteKit beta and new way to use slots
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Two projects that have been months (even years) in the making have made their way out into the world. SvelteKit is now in public beta and slotted components are now available in Svelte!
## What's up with SvelteKit?
[SvelteKit](https://kit.svelte.dev/) - Svelte's versatile framework for building SSR, serverless applications, or SPAs - is now officially in public beta. Expect bugs! Lots more detail in the [latest blog post](https://svelte.dev/blog/sveltekit-beta). Want to know when 1.0 is close? Check out the milestone on [github](https://github.com/sveltejs/kit/milestone/2).
Want to learn more about how to get started, what's different compared to Sapper, new features and migration paths? Check out this week's [episode of Svelte Radio](https://www.svelteradio.com/episodes/svelte-kit-public-beta) for a deep dive with Antony, Kev and Swyx.
## New in Svelte & Language Tools
- Slotted components, including `<svelte:fragment slot="...">` lets component consumers target specific slots with rich content (**Svelte 3.35.0, Language Tools [104.5.0](https://github.com/sveltejs/language-tools/releases/tag/extensions-104.5.0)**, check out the [docs](https://svelte.dev/docs#template-syntax-svelte-fragment) and the [tutorial](https://svelte.dev/tutorial/svelte-fragment))
- Linked editing now works for HTML in Svelte files (**Language Tools, [104.6.0](https://github.com/sveltejs/language-tools/releases/tag/extensions-104.6.0)**)
- Type definitions `svelte.d.ts` are now resolved in order, allowing library authors to ship type definitions with their svelte components (**Language Tools, [104.7.0](https://github.com/sveltejs/language-tools/releases/tag/extensions-104.7.0)**)
- [vite-plugin-svelte](https://github.com/sveltejs/vite-plugin-svelte) is available for general use of Svelte in Vite. `npm init @vitejs/app` includes Svelte options using this plugin.
---
## Community Showcase
**Apps & Sites**
- [Nagato](https://nagato.app/) is a task management tool that connects popular time tracking and to-do tools all in one place.
- [type-kana](https://type-kana.cass.moe/setup) is a quiz app to help you learn ひらがな (hiragana) and カタカナ (katakana), the Japanese syllabaries.
- [Pittsburgh Steps](https://pittsburgh-steps.samlearner.com/) is an interactive map of the more than 800 sets of public outdoor stairways in Pittsburgh, PA.
- [Music Mode Wheels](https://tobx.github.io/music-mode-wheels/) is a website that displays music modes as interactive wheels.
- [Critical Notes](https://www.critical-notes.com/) helps game masters and players keep track of their roleplaying games campaigns and adventures.
- [Svelte Game of Life](https://github.com/alanrsoares/svelte-game-of-life) is an educational implementation of Conway's Game of Life in TypeScript + Svelte
- [foxql](https://github.com/foxql) is a peer to peer full text search engine that runs on your browser.
**Demos, Libraries, Tools & Components**
- [svelte-nodegui](https://github.com/nodegui/svelte-nodegui) is a way to build performant, native and cross-platform desktop applications with Node.js and Svelte
- [Svelte Story Format](https://www.npmjs.com/package/@storybook/addon-svelte-csf) allows you to write your "stories" in Storybook using the Svelte syntax. More info in the [Storybook blog](https://storybook.js.org/blog/storybook-for-svelte/)
- [SelectMadu](https://github.com/pavish/select-madu) is a replacement for the select menu, with support for searching, multiple selections, async data loading and more.
- [Svelte Checklist](https://www.npmjs.com/package/svelte-checklist) is a customizable CheckList built with Svelte.
- [Suspense for Svelte](https://www.npmjs.com/package/@jamcart/suspense) is a Svelte component that implements the core idea of React's `<Suspense>`.
- [MiniRx](https://spierala.github.io/mini-rx-store/) is a RxJS Redux Store that works with Svelte and TypeScript
- [svelte-formly](https://github.com/arabdevelop/svelte-formly) generates dynamic forms for Svelte and Sapper
- [7ty](https://www.npmjs.com/package/@jamcart/7ty) is a static site generator that uses Svelte, supports partial hydration of components, and uses file based routing resembling Sapper and 11ty.
**Want to contribute your own component?** Submit a [Component](https://sveltesociety.dev/components) to the Svelte Society site by making [a PR to this file](https://github.com/svelte-society/sveltesociety.dev/blob/master/src/pages/components/components.json).
**Starters**
- [sveltekit-electron](https://github.com/FractalHQ/sveltekit-electron) is a starter kit for Electron using SvelteKit
- [sveltekit-tailwindcss-external-api](https://github.com/acidlake/sveltekit-tailwindcss-external-api) is everything you need to build a Svelte project with TailwindCSS and an external API, powered by create-svelte.
- [Sapper Netlify](https://www.npmjs.com/package/sapper-netlify) is a Sapper project that can run on a Netlify function.
**Looking for a particular starter?** Check out [svelte-adders](https://github.com/svelte-add/svelte-adders) and a number of other template examples at the community site [sveltesociety.dev](https://sveltesociety.dev/templates/)
**Learning Resources**
- [How to Build a Website with Svelte and SvelteKit](https://prismic.io/blog/svelte-sveltekit-tutorial) is a step-by-step tutorial walking through the new SvelteKit setup.
- [A Svelte store for prefers-reduced-motion](https://geoffrich.net/posts/svelte-prefers-reduced-motion-store/) demonstrates how to make a custom Svelte store whose value will indicate whether the user has requested reduced motion and improve accessibility.
- [TypeScript support in Svelte](https://developer.mozilla.org/en-US/docs/Learn/Tools_and_testing/Client-side_JavaScript_frameworks/Svelte_TypeScript) is an MDN guide to using TypeScript in Svelte.
- [How to merge cells with svelte-window](https://gradientdescent.de/merging-cells/) is a walkthrough of svelte-window, a port of the popular react-window tool for merging table cells. For more on this migration, see [from react-window 1:1 to svelte-window](https://gradientdescent.de/porting-react-window/).
- [Easy-to-Embed Svelte Components](https://codeandlife.com/2021/03/06/easy-to-embed-svelte-components/) explains how to use Rollup and a script tag to embed Svelte components anywhere.
- [Convert Svelte project from Rollup to Snowpack](https://www.youtube.com/watch?v=-sHcqj4YLeQ) walks through a common migration pattern on video.
- [How to internationalize routing in Svelte & Sapper](https://www.leaf.cloud/blog/how-to-internationalize-routing-in-svelte-sapper?utm_medium=story&utm_source=reddit.com&utm_campaign=awareness&utm_content=sapper_routing) explains how leaf.cloud translated their site to Dutch.
- [Svelte Store: Reactive context using Svelte Store](https://www.youtube.com/watch?v=-rTnWlbdjoY) is a video answer to the question, "How do we make [a] context value reactive?"
- [Creating Social Sharing Images with Cloudinary and Svelte](https://www.youtube.com/watch?v=-Si5o-R7KHY) is a video from Cloudinary that demonstrates how to dynamically develop Open Graph images and Twitter Cards for a JAMstack website.
## See you next month!
Got something to add? Join us on [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs)!

@ -1,76 +0,0 @@
---
title: "What's new in Svelte: May 2021"
description: Working toward SvelteKit 1.0 and a showcase full of SvelteKit sites!
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Last week, Svelte Summit blew us away with a mountain of content! [Check out the full recording](https://www.youtube.com/watch?v=fnr9XWvjJHw) or an audio-only (p)review [on Svelte Radio](https://www.svelteradio.com/episodes/svelte-summit-party-episode). Now let's get into this month's news...
## New features in the Svelte Compiler
- `:global()` is now supported as part of compound CSS selectors (**3.38.0**, [Example](https://svelte.dev/repl/54148fd2af484f2c84977c94e523c7c5?version=3.38.0))
- CSS custom properties can now be passed to components for use cases such as theming (**3.38.0**, [Docs coming soon](https://github.com/sveltejs/svelte/issues/6268))
## New in SvelteKit
- [kit.svelte.dev](https://kit.svelte.dev/) has a fresh new look and the [SvelteKit Demo Site](https://netlify.demo.svelte.dev/) got a fresh set of paint. Check it out by running `npm init svelte@next`
- You can now use `@sveltejs/adapter-static` to create a single-page app or SPA by specifying a fallback page ([PR](https://github.com/sveltejs/kit/pull/1181), [Docs](https://github.com/sveltejs/kit/tree/master/packages/adapter-static))
- Disable Server-side Rendering (SSR) app-wide or on a page-by-page basis ([PR](https://github.com/sveltejs/kit/pull/713))
- Error messages thrown during pre-rendering are now much more informative and readable ([PR](https://github.com/sveltejs/kit/pull/1062), [Docs](https://kit.svelte.dev/docs/layouts#error-pages))
- Layouts can now be reset to prevent pages from inheriting the root layout. This is useful if you have a specific layout for a page or i18n variation ([PR](https://github.com/sveltejs/kit/pull/1061), [Docs](https://kit.svelte.dev/docs/layouts#resets))
- `fetch` in SvelteKit code will now use the environment-provided implementation, whenever possible. If `fetch` is unavailable, it will be polyfilled by adapters ([PR](https://github.com/sveltejs/kit/pull/1066), [Docs](https://kit.svelte.dev/docs/loading#input-fetch))
## New in Svelte & Language Tools
- `svelte-preprocess` now supports the "extends" field of the tsconfig.json (4.7.2)
- HTML `style` attributes now have hover & auto-complete. Foreign namespaces and ESM configs are now supported in the Svelte language server & extensions
- The Svelte language tools can now infer slot/event types from their props if a generic relationship between them was defined
---
## Community Showcase
**Apps & Sites**
- [gitpod.io](https://github.com/gitpod-io/website) recently rewrote its site with SvelteKit
- [highlight eel](https://highlighteel.com/) is a web-based editor to mark your favorite parts of any YouTube video to clip and share with anyone
- [The Far Star Mission](https://thefarstar.apotheus.net/) is an interactive audiobook companion to the album, The Far Star by Apotheus
- [JavaScript quiz](https://github.com/nclskfm/javascript-quiz) is a small quiz application that saves your answers locally
- [ExtensionPay](https://extensionpay.com/) lets developers accept secure payments in browser extensions with no backend server code.
- [mk48.io](https://mk48.io/) is a naval warship game made with SvelteKit
- [Frog Safety](https://frog-safety.vercel.app/) is a guide for African Dwarf Frogs and the API freshwater master kit
- [Stardew Valley Character Preview](https://github.com/overscore-media/stardew-valley-character-preview) loads your character's attributes from your Stardew Valley savefile and lets you play around with different outfits, colours, and accessories.
**Demos, Libraries, Tools & Components**
- [svelte-parallax](https://github.com/kindoflew/svelte-parallax) is a spring-based parallax component for Svelte
- [@svelte-plugins/viewable](https://github.com/svelte-plugins/viewable) is a simple rule-based approach to tracking element viewability.
- [Sveltekit-JUI](https://github.com/Wolfr/sveltekit-jui) is a kit of UI components to be used in conjunction with Svelte and Svelte Kit.
- [EZGesture](https://github.com/mhmd-22/ezgesture#integrating-with-other-frameworks) makes it easy to add gestures functionality with simple native DOM events
**Want to contribute your own component?** Submit a [Component](https://sveltesociety.dev/components) to the Svelte Society site by making [a PR to this file](https://github.com/svelte-society/sveltesociety.dev/blob/master/src/pages/components/components.json).
**Starters**
- [How to use Vercel Analytics with SvelteKit](https://ivoberger.com/posts/using-vercel-analytics-with-svelte-kit) teaches how to track Web Vitals across your users' devices
- [Asp.NETCore + Svelte + Vite](https://github.com/Kiho/aspcore-spa-cli/tree/master/samples/SviteSample) connects the three frameworks with SpaCliMiddleware (VS2019)
- [Add CoffeeScript to Svelte](https://github.com/Leftium/coffeescript-adder) is an experimental command to run to add CoffeeScript to your SvelteKit project or Vite-powered Svelte app
- [Adds Supabase to Svelte](https://github.com/joshnuss/svelte-supabase) is an experimental command to run to add Supabase to your SvelteKit project
- [svelte-babylon](https://github.com/SectorXUSA/svelte-babylon) lets you use BabylonJS like A-Frame through reactive Svelte Components
**Looking for a starter or integration?** Check out [svelte-adders](https://github.com/svelte-add/svelte-adders) and a number of other template examples at the community site [sveltesociety.dev](https://sveltesociety.dev/templates)
**Learning Resources**
- [Amazing macOS Dock animation in Svelte](https://dev.to/puruvj/amazing-macos-dock-animation-in-svelte-5hfb) demonstrates how nice Svelte and popmotion look together
- [Solving the Tower of Hanoi with recursive Svelte templates](https://geoffrich.net/posts/svelte-tower-of-hanoi/) incorporates the `<svelte:self>` element into a common computer science problem
- [DIY SvelteKit CDK adapter](https://dev.to/juranki/diy-sveltekit-cdk-adapter-3enp) puts together SvelteKit and AWS CDK
- Fireship's [Svelte in 100 Seconds](https://www.youtube.com/watch?v=rv3Yq-B8qp4) is a quick and easy introduction to Svelte's core concepts
- [Tech Downtime](https://www.youtube.com/watch?v=tsePBA2JC7o&list=PLualcIC6WNK1LHIYx2Tg9AQfTQDv4zNPu) has been diving into SvelteKit in this playlist - from getting up and running to debugging.
- lihautan's latest video updates in the [Svelte 101](https://www.youtube.com/watch?v=rwYgOU0WmVk&list=PLoKaNN3BjQX3mxDEVG3oGJx2ByXnue_gR&index=59) and [Svelte Store](https://www.youtube.com/watch?v=p4GmT0trCPE&list=PLoKaNN3BjQX3fG-XOSwsPHtnV8FUY6lgK&index=19) playlists cover slots, stores and context - and when to use which
- [DavidParkerW](https://www.youtube.com/c/DavidParkerW/playlists) has been exploring Svelte, Sapper and SvelteKit in some real-world scenarios, like [displaying a blog post list from an API](https://www.youtube.com/watch?v=kAPVFgFnxaM&list=PLPqKsyEGhUna6cvm6d4vZNI6gbt_0S4Xx&index=15)
## See you next month!
Got something to add? Join us on [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs)!

@ -1,65 +0,0 @@
---
title: "What's new in Svelte: June 2021"
description: Progress towards SvelteKit 1.0 and tighter TypeScript/Svelte integrations in language tools
author: Daniel Sandoval
authorURL: https://desandoval.net
---
This month, we saw lots of contributions to SvelteKit and its docs. The language tools also got some new features, most notably deeper integration with Svelte files within JavaScript or TypeScript files. Let's jump into the updates...
## New in SvelteKit
- `svelte.config.js` config files are now loaded in ESM format (`.js` instead of `.cjs`).
- AMP pages will now use the rendered CSS, rather than emitted CSS
- `svelte-check` has been added to the TypeScript template ([sveltejs/kit#1556](https://github.com/sveltejs/kit/pull/1556))
- Support for https keypair [sveltejs/kit#1456](https://github.com/sveltejs/kit/pull/1456)
- Now bundling Vite with SvelteKit and using an upgraded version. Remove Vite from your `package.json` if it's there
- Etags for binary responses [sveltejs/kit#1382](https://github.com/sveltejs/kit/pull/1382)
- Renamed `$layout` to `__layout` and `$error` to `__error`
- Removed `getContext` in favor of `request.locals`
- Renamed `.svelte` output directory to `.svelte-kit`. Update your `.gitignore` accordingly
- `trailingSlash: 'never' | 'always' | 'ignore'` is now available in the config. This should make it easier to build sites that work with static hosting providers that expect a trailing slash for `index.html` pages, and provides an escape hatch for anyone that needs more complex behaviour.
## Notable bug fixes in SvelteKit
- `adapter-netlify` got a fix [sveltejs/kit#1467](https://github.com/sveltejs/kit/pull/1467) and new documentation in the readme https://github.com/sveltejs/kit/tree/master/packages/adapter-netlify
- The router will no longer intercept navigation for URLs that the app does not own. This fixes a crash for apps that have `<a>` elements on the page with the same origin but don't share a base path with the app.
- Hash only changes are now handled by the router fixing the browser's "back" navigation between hash changes in some circumstances.
## New in Svelte & Language Tools
- Svelte 3.38.1 and 3.38.2 fixed an issue with hydration that was causing duplicate elements. If you're seeing this in your project, be sure to update the latest version!
- A new TypeScript plugin provides deeper integration with Svelte files within JavaScript or TypeScript files. This includes diagnostics, references and renaming of variables. It comes packaged with the VS Code extension but is turned off by default for now. You can enable it through [this setting](https://github.com/sveltejs/language-tools/tree/master/packages/svelte-vscode#svelteenable-ts-plugin). We encourage you to test it out and [provide feedback](https://github.com/sveltejs/language-tools/issues/580)
- In the latest version of `svelte-check` you can now provide the path to your `tsconfig.json` or `jsconfig.json`. Example: `svelte-check --tsconfig "./tsconfig.json"`. This ensures the diagnostics are only run on files that are referenced in that config. It also runs diagnostics on JavaScript and/or TypeScript files which removes the need to run another check (like `tsc --noEmit`) for non-Svelte files (`svelte-check` version [**1.6.0**](https://github.com/sveltejs/language-tools/releases/tag/svelte-check-1.6.0))
- The VS Code extension and `svelte-check` got a new major release. Previously, properties that had no initializer (`export let foo;`) were only required if the user was using both TypeScript and activated `strict` mode. This is changed now: People using TypeScript, and those using `checkJs` also in JavaScript files, will now always have these properties marked as required (`svelte-check` version [**2.0.0**](https://github.com/sveltejs/language-tools/releases/tag/svelte-check-2.0.0), extension version [**105.0.0**](https://github.com/sveltejs/language-tools/releases/tag/extensions-105.0.0))
---
## Community Showcase
**Apps & Sites**
- [vidu](https://github.com/pa-nic/vidu) is a minimal web analytics collector and dashboard
- [River Runner](https://river-runner.samlearner.com/) is a virtual way to follow rivers downstream - built with Mapbox and Svelte.
- [JSDoc Type Generator](https://rafistrauss.github.io/jsdoc-generator/) generates JSDoc types for valid JSON.
- [pagereview.io](https://pagereview.io/) is a website feedback tool that lets you leave comments directly on the site being reviewed.
- [gamesroom.io](https://gamesroom.io/) is an online board game platform with video chat built-in.
- [Greedy Goblin](https://greedygoblin-fe11c.web.app/) is a recipe app for old-school Runescape players.
- [hashbrown.geopjr.dev](https://hashbrown.geopjr.dev/) is a GNOME-shell inspired webpage to learn about, explore the source code and download the Hashbrown GTK app ([link to source](https://github.com/GeopJr/Hashbrown/tree/website)).
**Libraries, Tools & Components**
- [svelte-image-crop](https://novacbn.github.io/svelte-image-crop/) is a simple click'n'drag image cropping library using Web APIs.
- [svelte-datepicker](https://github.com/andrew-secret/svelte-datepicker) is a lightweight and inclusive date picker build with Svelte.
- [svelte-regex-router](https://www.npmjs.com/package/svelte-regex-router) is a simple, lightweight library for you to easily handle routes in your Svelte application.
- [Svelte Micro](https://www.npmjs.com/package/svelte-micro) is a light & reactive one-component router for Svelte.
- [svelte-entity-store](https://www.npmjs.com/package/svelte-entity-store) is to provide a simple, generic solution for storing collections of entity objects.
- [svelte-animation-store](https://github.com/joshnuss/svelte-animation-store) is a store that is based on Svelte's tweened store, that lets you pause, continue, reset, replay, reverse or adjust speed of a tween.
**Want to contribute a component?** Submit a [Component](https://sveltesociety.dev/components) to the Svelte Society site by making [a PR to this file](https://github.com/svelte-society/sveltesociety.dev/blob/master/src/pages/components/components.json).
## See you next month!
Did we miss something? Join us on [Svelte Society](https://sveltesociety.dev/), [Reddit](https://www.reddit.com/r/sveltejs/) and [Discord](https://discord.com/invite/yy75DKs)!

@ -1,65 +0,0 @@
---
title: "What's new in Svelte: July 2021"
description: Keeping cool with fixes, TypeScript tooling and tonnes of new features
author: Daniel Sandoval
authorURL: https://desandoval.net
---
As the northern hemisphere heats up, Svelte has stayed cool with lots of performance and bug fixes, better TypeScript support, and lots of new components & tools from around the ecosystem. Let's take a peek 👀
## New in SvelteKit
- `adapter-node` now precompresses assets using gzip & brotli ([#1693](https://github.com/sveltejs/kit/pull/1693))
- Support for TypeScript transpilation has been added to the `svelte-kit package` tooling ([#1633](https://github.com/sveltejs/kit/pull/1633))
- Improved caching defaults in `adapter-node` ([#1416](https://github.com/sveltejs/kit/pull/1416))
- Allow configuring Rollup output options ([#1572](https://github.com/sveltejs/kit/pull/1572))
- Fixed usage of SSL with HMR ([#1517](https://github.com/sveltejs/kit/pull/1517))
## Features & bug fixes from around svelte/*
- [Svelte 3.38.3](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md#3383) (released June 22) includes a bunch of performance and bug fixes - including hydration optimizations, `this` preservation in bubbled events, and more!
- The latest language tools releases added support for prop renaming from outside of a component, PostCSS syntax grammar, and a `.d.ts` output target in `svelte2tsx` which can be used to create type definitions from Svelte files.
- Also in language tools, some long-awaited experimental features for enhanced TypeScript support were added - including explicitly typing all possible component events or slots, and using generics. Have a look at [the RFC](https://github.com/sveltejs/rfcs/pull/38) for more details and leave feedback in [this issue](https://github.com/sveltejs/language-tools/issues/442) if you are using it.
- `svelte-scroller` got some quality-of-life fixes in 2.0.7 - fixing an initial width bug and updating its `index` more conservatively
## Coming soon to Svelte
- Constants in markup ([RFC](https://github.com/sveltejs/rfcs/blob/master/text/0000-markup-constants.md)): Adds a new `{@const ...}` tag that defines a local constant ([PR](https://github.com/sveltejs/svelte/pull/6413))
---
## Community Showcase
**Apps & Sites**
- [SvelteThemes](https://sveltethemes.dev/) is a curated list of Svelte themes and templates built using svelte, sveltekit, elderjs, routify etc.
- [Beatbump](https://github.com/snuffyDev/Beatbump) is an alternative frontend for YouTube Music created using Svelte/SvelteKit.
- [Sveltuir](https://github.com/webspaceadam/sveltuir) is an app help you memorize the guitar fretboard
**Educational Content**
- [Svelte Radio: A Jolly Good Svelte Summer](https://share.transistor.fm/s/60880542) is a conversation about what's new in Svelte and a celebration of Svelte Radio's 1-year anniversary
- [Class properties in Svelte](https://navillus.dev/blog/svelte-class-props) is a refresher on the power of `class` for developers switching over to Svelte from React
- [Sveltekit Tutorial for Beginners](https://www.youtube.com/playlist?list=PLm_Qt4aKpfKjf77S8UD79Ockhwp_699Ms) is a video playlist for learning SvelteKit by WebJeda
- [How To Cache Dynamic Pages On Demand With A Service Worker In SvelteKit](https://jochemvogel.medium.com/how-to-cache-dynamic-pages-on-demand-with-a-service-worker-in-sveltekit-4b4a7652583d) walks through the power of service workers when used within SvelteKit for on-demand caching
- [Vue vs Svelte: Comparing Framework Internals](https://www.vuemastery.com/blog/vue-vs-svelte-comparing-framework-internals/) dives deep into the differences between Vue and Svelte from the inside out
- [Setting up a development environment for SvelteKit with Docker and Docker Compose](https://jenyus.web.app/blog/2021-05-30-setting-up-a-development-environment-for-sveltekit-with-docker-and-compose) walks through how to use Docker to create reusable development environments, no matter what kind of device you run your code on
- Scalable Scripts released three videos this month documenting how to deploy dockerized Svelte Apps to [AWS](https://youtu.be/VOs2Od5jYOc), [Azure](https://youtu.be/gdg4ne_uDm8) and [Google Cloud](https://youtu.be/_-uBb61Tikw)
- [Render Katex with Svelte from zero to hero](https://www.youtube.com/watch?v=euowJs9CblA) demonstrates how to implement Katex in a Svelte project
- [Using Custom Elements in Svelte](https://css-tricks.com/using-custom-elements-in-svelte/) shows some of the quirks to look out for when using custom elements in a Svelte site
**Libraries, Tools & Components**
- [svelte-pipeline](https://github.com/novacbn/svelte-pipeline) provides custom Javascript contexts and the Svelte Compiler as Svelte Stores, for REPLs, Editors, etc.
- [Sveltotron](https://github.com/Salemmous/sveltotron) is an Electron-based app made to inspect your Svelte app
- [svelte-qr-reader-writer](https://github.com/pleasemarkdarkly/svelte-qr-reader-writer) is a Svelte component that helps read and write data from QR codes
- [svelte-stack-router](https://www.npmjs.com/package/svelte-stack-router) Aims to make Svelte apps feel more native by routing with Stacks
- [svelte-typed-context](https://www.npmjs.com/package/svelte-typed-context) provides an interface which, when provided to `getContext` or `setContext`, allows for stricter types
- [svelte-modals](https://svelte-modals.mattjennings.io/) is a simple, flexible, zero-dependency modal manager for Svelte
**Want to contribute a component? Interested in helping make Svelte's presence on the web better?** Submit a Component to the Svelte Society site by making [a PR to this file](https://github.com/svelte-society/sveltesociety-2021/blob/main/src/routes/components/components.json) or check out [the list of open issues](https://github.com/svelte-society/sveltesociety-2021/issues) if you'd like to contribute to the Svelte Society rewrite in SvelteKit.
## See you next month!
Want more updates? Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs)!

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---
title: "What's new in Svelte: August 2021"
description: Shadow DOM, export and await - oh my!
author: Daniel Sandoval
authorURL: https://desandoval.net
---
From The Changelog ([JS Party Ep. 182](https://changelog.com/jsparty/182)) to Svelte Radio (Episodes [29](https://share.transistor.fm/s/adc23e84) and [30](https://share.transistor.fm/s/6316622d)), it seems that folks couldn't help but talk about Svelte, this month! Also, shadow DOM support and new export and await functionality are new in Svelte.
## New in Svelte
July was the most active month for the Svelte core repo since late 2019 as we really worked to reduce the number of outstanding PRs and saw the release of Svelte 3.39.0, 3.40.0, and 3.41.0. Tons of bug fixes were added as well as the following new features:
- The `|trusted` event modifier allows you to check if an event is trusted before it's called ([#6137](https://github.com/sveltejs/svelte/issues/6137))
- The new `svelte/ssr` package to support work on improving SvelteKit SSR ([#6416](https://github.com/sveltejs/svelte/pull/6416))
- A new `errorMode` compiler option to support improved preprocessing of TypeScript files ([#6194](https://github.com/sveltejs/svelte/pull/6194))
- You can now specify a `ShadowRoot` as the `target` when creating a component - making it possible to render Svelte components inside the shadow DOM ([#5869](https://github.com/sveltejs/svelte/issues/5869))
- The `export { ... } from` ([#2214](https://github.com/sveltejs/svelte/issues/2214)), `export let { ... } =` ([#5612](https://github.com/sveltejs/svelte/issues/5612)) and `{#await ... then/catch}` ([#6270](https://github.com/sveltejs/svelte/issues/6270)) syntaxes are all now supported in Svelte components
For a full list of features and bug fixes, check out the [Svelte changelog](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md).
## SvelteKit Updates
- `prerender.force` is now `prerender.onError` which lets you fine-tune which errors fail the build and which do not ([#2007](https://github.com/sveltejs/kit/pull/2007))
- esbuild's configuration is now exposed for use with SvelteKit adapters ([#1914](https://github.com/sveltejs/kit/pull/1914))
- Error messages are friendlier now for common config errors ([#1910](https://github.com/sveltejs/kit/pull/1910)) and compiler errors ([#1827](https://github.com/sveltejs/kit/pull/1827))
- Cookies will only be passed through if the target host is the same as the SvelteKit application or a more specific subdomain of it ([#1847](https://github.com/sveltejs/kit/pull/1847))
- index.js exports will now be changed to directory exports when packaging - making for nicer imports ([#1905](https://github.com/sveltejs/kit/pull/1905))
- Vite.js's `mode` is now exposed from `$app/env` ([#1789](https://github.com/sveltejs/kit/pull/1789))
- Better types across the board ([#1778](https://github.com/sveltejs/kit/pull/1778), [#1791](https://github.com/sveltejs/kit/pull/1791), [#1646](https://github.com/sveltejs/kit/pull/1646))
To see all updates to SvelteKit, check out the [SvelteKit changelog](https://github.com/sveltejs/kit/blob/master/packages/kit/CHANGELOG.md).
## Features & bug fixes from around svelte/*
- Language Tools now better support the "Workplace Trust" functionality (used in VS Code)
- In svelte2tsx, ambient type declarations are now renamed to avoid conflicting declarations in the future. Users are now expected to provide the ambient type definitions themselves - fixing JS output
- Sapper released v0.29.2 which fixes regex routes, status codes when requesting a directory, and exports when a user has not provided a `base` tag ([changelog](https://github.com/sveltejs/sapper/blob/master/CHANGELOG.md))
---
## Community Showcase
**Apps & Sites**
- [Parsnip](https://www.parsnip.ai/) is a mobile-first, progressive-web-app that helps you to learn to cook at home. Check out the [conversation on Reddit](https://www.reddit.com/r/sveltejs/comments/oearb9/learning_to_cook_at_home_with_parsnip_built/) for all the geeky details.
- [Central Bank Digital Currency (CBDC) tracker](https://www.atlanticcouncil.org/cbdctracker/) is a site that keeps track of how countries around the world are adopting digital currencies.
- [Svelte Commerce](https://github.com/itswadesh/svelte-commerce) is an advanced frontend platform for eCommerce based on Sveltekit.
- [neovimcraft](https://neovimcraft.com/) is a SvelteKit site dedicated to neovim plugins
**Looking for a Svelte project to work on? Interested in helping make Svelte's presence on the web better?** Check out [the list of open issues](https://github.com/svelte-society/sveltesociety-2021/issues) if you'd like to contribute to the Svelte Society rewrite in SvelteKit.
**Educational Content**
- [How I Built a Cross-Platform Desktop Application with Svelte, Redis, and Rust](https://css-tricks.com/how-i-built-a-cross-platform-desktop-application-with-svelte-redis-and-rust/) is a blog post by Luke Edwards, Svelte maintainer and Developer Advocate from Cloudflare.
- [How to Create a Blog with SvelteKit and Strapi](https://strapi.io/blog/how-to-create-a-blog-with-svelte-kit-strapi) is a step-by-step tutorial by Aarnav Pai from Strapi
- [Sveltekit Markdown Blog](https://www.youtube.com/watch?v=sKKgT0SEioI&list=PLm_Qt4aKpfKgonq1zwaCS6kOD-nbOKx7V) is a YouTube tutorial series by WebJeda.
- [Using Custom Elements in Svelte](https://css-tricks.com/using-custom-elements-in-svelte/) is a deep dive into custom elements by Geoff Rich.
- [learn / graphql / svelte](https://hasura.io/learn/graphql/svelte-apollo/introduction/) is a free 2-hour GraphQL course course from Hasura.
- [How to add Magic Link to a SvelteKit application](https://magic.link/posts/magic-svelte) is a guide to the popular password-less login pattern.
**Libraries, Tools & Components**
- [Svelte-Capacitor](https://github.com/drannex42/svelte-capacitor/) just released v2.0.0 - making it even easier to build hybrid mobile apps for iOS and Android using Svelte and Capacitor with near native performance.
- [svelte-remixicon](https://github.com/ABarnob/svelte-remixicon) is an icon library for Svelte based on Remix Icon, consisting of more than 2000 icons.
- [SveltePress](https://github.com/GeopJr/SveltePress) is a documentation tool built on top of SvelteKit.
- [Svelte Starter Kit](https://github.com/one-aalam/svelte-starter-kit/tree/auth-supabase) is a boilerplate to quckly get up and running with Svelte, with Auth and User Profiles powered by Supabase.
- [Kahi UI](https://github.com/novacbn/kahi-ui) is a Svelte-first UI kit with Dark Mode built-in.
- [typesafe-i18n](https://github.com/ivanhofer/typesafe-i18n) is an opinionated, fully type-safe, lightweight localization library for TypeScript and JavaScript projects with no external dependencies.
Check out the community site [sveltesociety.dev](https://sveltesociety.dev/templates/) for more templates, adders and adapters from across the Svelte ecosystem.
## See you next month!
Want more updates? Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs)!

@ -1,83 +0,0 @@
---
title: "What's new in Svelte: September 2021"
description: StackOverflow's most loved web framework
author: Daniel Sandoval
authorURL: https://desandoval.net
---
This month, Svelte was [voted StackOverflow's most loved web framework](https://insights.stackoverflow.com/survey/2021#section-most-loved-dreaded-and-wanted-web-frameworks), Tan Li Hau [talked to Svelte Radio](https://share.transistor.fm/s/84c7521b) about his [Svelte-filled YouTube channel](https://www.youtube.com/channel/UCbmC3HP3FaAFdcZkui8YoMQ), and SvelteKit made even more progress towards its 1.0 release!
## New in Svelte
- `use:actions` can now be used on `<svelte:body>` (**3.42.0**)
- `HTMLElement`, `SVGElement` (**3.42.2**) and `BigInt` (**3.42.3**) are now known globals
- There is less code in Svelte's output thanks to the following improvements in **3.42.2**:
- Whitespace is now collapsed in class and style attributes
- Hydrated components have been updated to only rely upon helpers for creating the types of elements present in the component
- Scaling is now accounted for in `flip` animations (**3.42.2**)
- All `<option>`s in a `<select>` are now deselected when the bound value doesn't match any of them (**3.42.2**)
For a full list of features and bug fixes, check out the [Svelte changelog](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md).
## SvelteKit Updates
Svelte maintainers are [looking for help getting SvelteKit to 1.0](https://github.com/sveltejs/kit/issues/2100). We've knocked out over 100 issues that were on the 1.0 milestone. There's only a couple dozen left and we'd love a hand making that list a bit shorter!
If you'd like to help, please consider working on any of the [1.0 milestone issues](https://github.com/sveltejs/kit/issues?q=is%3Aopen+is%3Aissue+milestone%3A1.0).
The focus this past month was on continuing to iron out any kinks, with well over 100 PRs merged. A few new features went in as well...
- SvelteKit will now detect if a prerendered app is trying to access a query parameter and return an error instead of failing silently ([#2104](https://github.com/sveltejs/kit/pull/2104))
- `adapter-node` now lets you [add the Kit middleware to your own server](https://kit.svelte.dev/faq#integrations) for use with other middleware. You can also [add middleware in dev mode](https://kit.svelte.dev/faq#how-do-i-use-x-with-sveltekit-how-do-i-use-middleware) with more improvements to come in this area
- The new [`sequence` helper lets you chain together multiple `handle` calls](https://kit.svelte.dev/docs/modules#sveltejs-kit-hooks)
- A new [`handleError` hook](https://kit.svelte.dev/docs/hooks#handleerror) gives you the option to send data to an error tracking service, or to customise the formatting before printing the error to the console.
- `adapter-node` can now listen on socket path ([#2048](https://github.com/sveltejs/kit/pull/2048))
To see all updates to SvelteKit, check out the [SvelteKit changelog](https://github.com/sveltejs/kit/blob/master/packages/kit/CHANGELOG.md).
---
## Community Showcase
**Apps & Sites**
- [macos-web](https://github.com/PuruVJ/macos-web) by @puruvjdev has been rebuilt with Svelte from the ground up. Check out all the details in this [Twitter thread](https://twitter.com/puruvjdev/status/1426267327687847939)
- [Brave Search](https://search.brave.com/) is using Svelte
- [exatorrent](https://github.com/varbhat/exatorrent) is a self-hostable, easy-to-use, lightweight and feature-rich torrent client written in Go and Svelte
- [json2TsTypes](https://github.com/jatinhemnani01/json2TsTypes) is a simple tool which will convert your JSON to Typescript Types/Interfaces
- [Histogram.dev](https://histogram.dev/) generates histograms for each feature in a CSV
- [cybernetic.dev](https://cybernetic.dev/) is a collection of data-centric UI experiments made while learning Svelte
- [LunaNotes](https://chrome.google.com/webstore/detail/lunanotes-youtube-video-n/oehoffnnkgcdacmbkhmlbjedinpampak?hl=en) is a Chrome extension to help with taking YouTube video notes
- [theia.games](https://theia.games/#dev)'s built-in 3D environment editor lets you create a VR world with a menu built in Svelte
- [Ferrum](https://github.com/probablykasper/ferrum) is a music library and player available for Mac, Windows or Linux
- [Fluid Earth](https://github.com/byrd-polar/fluid-earth) is an interactive WebGL application for visualizing Earth's atmosphere and oceans
**Looking for a Svelte project to work on? Interested in helping make Svelte's presence on the web better?** Check out [the list of open issues](https://github.com/svelte-society/sveltesociety-2021/issues) if you'd like to contribute to the Svelte Society rewrite in SvelteKit.
**Educational Content**
- [Tauri with Standard Svelte or SvelteKit](https://medium.com/@cazanator/tauri-with-standard-svelte-or-sveltekit-ad7f103c37e7) walks through how to setup Svelte with Tauri, a new light-weight framework for developing cross-platform hybrid desktop applications
- [Svelte - Web App Development Reimagined [An Intro to Svelte]](https://www.youtube.com/watch?v=4CGzFwHoD0A&list=PLEx5khR4g7PKSASVAXXiAhkyx02_OeruP) is a great intro talk from the goto; conference
- [LevelUpTuts - Even More 5 Things I Like More In Svelte Than React](https://www.youtube.com/watch?v=ISmnG2sIOeM) highlights Svelte's approach to refs (don't need them), meta tags and more
- [State Management in Svelte Applications](https://auth0.com/blog/state-management-in-svelte-applications/) is a tutorial on how to use the Svelte state management store to manage state in Svelte applications
- [Migrating from Sapper to SvelteKit](https://shipbit.de/blog/migrating-from-sapper-to-svelte-kit/) is a review and retrospective of ShipBit's migration from Sapper
**Libraries, Tools & Components**
- [svelte-stripe-js](https://github.com/joshnuss/svelte-stripe-js) is everything you need to add Stripe to your Svelte project. 100% SvelteKit compatible
- [svelte-steps](https://github.com/shaozi/svelte-steps) is a customizable step component written in Svelte
- [simple-optics-module](https://gitlab.com/Samzelot/simple-optics-module) is an online open source optics tool for experimenting and teaching geometrical optics
- [inlang](https://github.com/samuelstroschein/inlang) is an internationalization (i18n) tool for SvelteKit apps
- [Sveno](https://github.com/pocinnovation/sveno) is a component transpiler that transforms React components to Svelte components
- [svelte-useactions](https://github.com/paolotiu/svelte-useactions) is a fully typed library for passing actions to components
- [Svelte-Element-Query](https://github.com/leveluptuts/Svelte-Element-Query) is a 322b library/action for element queries
- [svelte-meta-tags](https://github.com/oekazuma/svelte-meta-tags) is a plug-in that makes managing SEO easier in Svelte projects
- [svelte-domtree](https://github.com/alex-knyaz/svelte-domtree) lets you visualize the DOM - similar to DOM tree in Chrome DevTools
- [Diffx](https://github.com/jbjorge/diffx/tree/master/svelte), a cross-framework state management library, just added Svelte support
- [svelte-ionic-starter](https://github.com/Zettexe/svelte-ionic-starter) a project template for Svelte + Ionic + CapacitorJS apps with live reload and iOS/Android build targets
- [demo-sveltekit-sanity](https://github.com/stephane-vanraes/demo-sveltekit-sanity/) is a starter kit for SvelteKit and Sanity, an open source React CMS
Check out the community site [sveltesociety.dev](https://sveltesociety.dev/templates/) for more templates, adders and adapters from across the Svelte ecosystem.
## See you next month!
Want more updates? Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs)!

@ -1,99 +0,0 @@
---
title: "What's new in Svelte: October 2021"
description: A whole year of "What's new in Svelte"
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Hey y'all 👋 It's been 1 year since "What's new in Svelte" started being cross-posted to the Svelte blog. I wanted to take this moment at the top to thank all of you for reading and for all the contributors every month. From the maintainers to everyone who posts their work in the Discord and Reddit, it's amazing to witness all the effort that goes into making the Svelte community great.
Keep up the good work, everyone! Now, let's dive into this month's news...
## New around Svelte
- New additions to Svelte's export map now expose no-op versions of lifecycle functions for SSR (Svelte **3.43.0**)
- Custom components with a `src` attribute no longer break `svelte-native` builds (Svelte **3.42.4**)
- Svelte plugin users without [the TypeScript plugin](https://www.npmjs.com/package/typescript-svelte-plugin) enabled will now be prompted to enable it. It enhances TypeScript and JavaScript files with additional intellisense to interact with Svelte files. [Please leave feedback](https://github.com/sveltejs/language-tools/issues/580) if you are using it (Svelte extensions **105.4.0**)
- Event modifiers have been added to intellisense as autocomplete and hover info (Svelte extensions **105.4.0**)
- TypeScript users no longer have to strictly separate type imports and value imports when using Svelte version 3.39 or higher and `svelte-preprocess` version 4.9.5 or higher. This means you can now write `import { MyInterface, myValue } from './somewhere'` instead of `import type { MyInterface } from './somewhere'; import { myValue } from './somewhere'`. Huge thanks to community member [@SomaticIT](https://github.com/SomaticIT) who mainly implemented this!
For a full list of features and bug fixes, check out the [Svelte changelog](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md).
## SvelteKit Updates
Nearly 100 PRs committed again this past month, but there's still lots to do and Svelte maintainers are [looking for help getting SvelteKit to 1.0](https://github.com/sveltejs/kit/issues/2100). Antony said it well in a [recent comment](https://github.com/sveltejs/kit/issues/2100#issuecomment-895446285) on the issue:
> If you think you are too n00b to contribute (you're not), then add tests, or write tests for the feature you want to add, before you add it! Start small, and learn the codebase that way.
If you'd like to help, please consider working on any of the [1.0 milestone issues labeled with "help wanted"](https://github.com/sveltejs/kit/issues?q=is%3Aopen+is%3Aissue+milestone%3A1.0+label%3A%22help+wanted%22).
Notable SvelteKit improvements this month include...
- Service workers are now allowed to access files using the `$lib` alias ([#2326](https://github.com/sveltejs/kit/pull/2326))
- Svelte libraries should now work out-of-the-box without any Vite configuration ([#2343](https://github.com/sveltejs/kit/pull/2343))
- Improvements to package exports field ([#2345](https://github.com/sveltejs/kit/pull/2345) and [#2327](https://github.com/sveltejs/kit/pull/2327))
- [breaking] The `prerender.pages` config option has been renamed to `prerender.entries` ([#2380](https://github.com/sveltejs/kit/pull/2380))
- A new generic argument has beend added to allow typing Body from hooks ([#2413](https://github.com/sveltejs/kit/pull/2413))
- The `svelte` field will be added to package.json when running the package command ([#2431](https://github.com/sveltejs/kit/pull/2431))
- [breaking] The `context` parameter of the load function was renamed to `stuff` ([#2439](https://github.com/sveltejs/kit/pull/2439))
- Added an `entryPoint` option for building a custom server with `adapter-node` ([#2414](https://github.com/sveltejs/kit/pull/2414))
- `vite-plugin-svelte` improved support for [useVitePreprocess](https://github.com/sveltejs/vite-plugin-svelte/blob/main/docs/config.md#usevitepreprocess), which uses Vite to automatically preprocess TypeScript, PostCSS, Scss, etc in Svelte components ([#173](https://github.com/sveltejs/vite-plugin-svelte/pull/173))
To see all updates to SvelteKit, check out the [SvelteKit changelog](https://github.com/sveltejs/kit/blob/master/packages/kit/CHANGELOG.md).
---
## Community Showcase
**Apps & Sites**
- [radiofrance](https://www.radiofrance.fr/) just migrated their website to SvelteKit
- [FLAYKS](https://flayks.com/) is the portfolio site for Félix Péault made with SvelteKit, Sanity, and Anime.js
- [hirehive](https://www.hirehive.com/) is a candidate and job tracking site
- [Microsocial](https://microsocial.xyz/) is an experimental Peer-to-Peer Social Platform
- [Dylan Ipsum](https://www.dylanlyrics.app/) is a random text generator to replace lorem ipsum with Bob Dylan lyrics
- [Chip8 Svelte](https://github.com/mikeyhogarth/chip8-svelte) is a CHIP-8 emulator frontend, built on top of CHIP8 Typescript
**Looking for a Svelte project to work on? Interested in helping make Svelte's presence on the web better?** Check out [the list of open issues](https://github.com/svelte-society/sveltesociety-2021/issues) if you'd like to contribute to the Svelte Society rewrite in SvelteKit.
**Podcasts Featuring Svelte**
- [Syntax Podast: From React to SvelteKit](https://podcasts.apple.com/us/podcast/from-react-to-sveltekit/id1253186678?i=1000536276106) Scott talks with Wes about moving Level Up Tutorials from React to SvelteKit — why he did it, how, benefits, things to watch out for, and more!
- [Web Rush Podcast: Svelte Tools and Svelte Society](https://www.webrush.io/episodes/episode-150-svelte-tools-and-svelte-society) Kevin Åberg Kultalahti talks about what Svelte Society is, what he's excited about with Svelte, how important documentation is to any product, and much _much_ more
- [Svelte: The Compiled Future of Front End](https://www.arahansen.com/the-compiled-future-of-front-end/) details the history of component-based frontends and how a compiler changes everything
- [Svelte Radio: Contributing to Svelte with Martin 'Grygrflzr' Krisnanto Putra](https://share.transistor.fm/s/10aa305c) Grygrflzr shares his journey to becoming a maintainer and his views on React, Vite and a host of other things
- [Svelte Radio: Routify 3 with Jake and Willow](https://share.transistor.fm/s/10aa305c) the Svelte Radio crew sits down with the maintainers of Routify and discusses the just-released Routify 3
- [JS Party: 1Password](https://twitter.com/geoffrich_/status/1441816829853253640?s=20) mentioned on the latest episode of The Changelog's JS Party that they use Svelte to power their in-page suggestions
**Educational Content**
- [How I built a blog with Svelte and SvelteKit](https://fantinel.dev/blog-development-sveltekit/) is an introduction to Svelte, SvelteKit and Progressive Enhancement with code examples
- [I built a decentralized chat dapp](https://www.youtube.com/watch?v=J5x3OMXjgMc) is a tutorial on how to use popular web3 technologies like GUN to build a decentralized web app (dapp)
- [Writing a Svelte Store with TypeScript](https://javascript.plainenglish.io/writing-a-svelte-store-with-typescript-22fa1c901a4) is a deep dive into writing Svelte stores with TypeScript
- [How Svelte scopes component styles](https://geoffrich.net/posts/svelte-scoped-styles/) explains scoping using classes and more complex CSS specifiers
- [SvelteKit Hooks](https://www.youtube.com/watch?v=RarufLoEL08) shows how to use hooks.js in Sveltekit.. When you're done, check out [Part 2](https://www.youtube.com/watch?v=RmIBG3G0-VY)
- [An early look at SvelteKit](https://www.infoworld.com/article/3630395/an-early-look-at-sveltekit.html) is a post from Infoworld walking through the features and onboarding of SvelteKit
**Libraries, Tools & Components**
- [sveltekit-netlify-cms](https://github.com/buhrmi/sveltekit-netlify-cms) is a SvelteKit skeleton app configured for use with Netlify CMS
- [SvelteFireTS](https://github.com/jacobbowdoin/sveltefirets) is a SvelteKit + Typescript + Firebase library inspired by Fireship.io
- [stores-x](https://github.com/Anyass3/stores-x) lets you use Svelte stores just like vueX
- [sveltekit-snippets](https://github.com/stordahl/sveltekit-snippets) is a VSCode extension that provides snippets for common patterns in SvelteKit & Vanilla Svelte
- [svelte-xactor](https://github.com/wobsoriano/svelte-xactor) is a middleware that allows you to easily convert your xactor machines into a global store that implements the store contract
- [vite-plugin-pages-svelte](https://github.com/aldy505/vite-plugin-pages-svelte) is a vite plugin for automatic filesystem-based routing
- [sveltio](https://www.npmjs.com/package/sveltio) is a Svelte wrapper for valtio - a proxy-state library
- [svelte-transition-classes](https://github.com/rmarscher/svelte-transition-classes) is a custom Svelte transition for adding and swapping CSS classes
- [Svelte-Boring-Avatars](https://github.com/paolotiu/svelte-boring-avatars) is Svelte port of the popular [Boring Avatars](https://github.com/boringdesigners/boring-avatars) React project
- [Svelte DataTables](https://github.com/homescriptone/svelte-datatables) brings DataTable, a popular JavaScript library allowing you to easily display your data in a user-friendly table, into your Svelte project.
- [focus-svelte](https://github.com/chanced/focus-svelte) is a focus trap for Svelte with zero dependencies
- [filedrop-svelte](https://github.com/chanced/filedrop-svelte) is a file dropzone action & component for Svelte
Check out the community site [sveltesociety.dev](https://sveltesociety.dev/templates/) for more templates, adders and adapters from across the Svelte ecosystem.
## Before you go, answer the call for speakers!
Svelte Summit Fall 2021 (happening 20 November 2021) is looking for speakers. Submit your talk propsoal before 30 October... all are welcome to present and attend.
### More info on the [sessionize site](https://sessionize.com/svelte-summit-fall-2021/)
Can't wait for the summit? Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs)!

@ -1,85 +0,0 @@
---
title: "What's new in Svelte: November 2021"
description: Over 5000 stars to light up the showcase
author: Daniel Sandoval
authorURL: https://desandoval.net
---
With SvelteKit crossing the [80% complete mark](https://github.com/sveltejs/kit/milestone/2), over [5000 stars](https://github.com/sveltejs/kit) on GitHub, and now having more usage than Sapper, there's never been a better time to try it out! Many in the community have, making for quite a large showcase this month...
Also, don't miss out on [Svelte Summit](https://sveltesummit.com/) on November 20th - featuring speakers from around the world. Keep an eye out for a watch party in your area 👀
Now onto what's new!
## New in Svelte and SvelteKit
- [svelte.dev](https://svelte.dev/) now runs on SvelteKit alongside [sveltesociety.dev](https://sveltesociety.dev). svelte.dev is a relatively complicated site with live code editing, authentication, and a markdown-based blog - making it a great way for us to really test out SvelteKit
- A new compiler option, `enableSourcemap`, provides more control over the compiler output for JS and CSS sourcemaps (**3.44.0**). With this new feature, SvelteKit and the Vite Svelte plugin can now properly handle environment variables in `.svelte` templates (See [sveltejs/kit#720](https://github.com/sveltejs/kit/issues/720) and [sveltejs/vite-plugin-svelte#201](https://github.com/sveltejs/vite-plugin-svelte/pull/201))
- The Svelte Language Tools now support reading the configuration of the VS Code CSS settings ([#1219](https://github.com/sveltejs/language-tools/issues/1219))
- `vite-plugin-svelte` added a new `experimental.prebundleSvelteLibraries` option that makes it much faster to load Svelte libraries with many components like icon libraries and UI frameworks. The option can be set in the root of `svelte.config.js`. Please test it out and give us feedback!
- SvelteKit will only route endpoints on the client, unless marked as `rel="external"` - reducing the size of the client JS and making it easier to refactor the router in the future ([2656](https://github.com/sveltejs/kit/pull/2656))
- SvelteKit no longer supports Node 12 ([2604](https://github.com/sveltejs/kit/pull/2604))
- SvelteKit was upgraded from Vite 2.6.0 to Vite 2.6.12 fixing an issue where Vite would corrupt the Svelte runtime (https://github.com/vitejs/vite/issues/4306). It also included two fixes from the SvelteKit team to avoid or make diagnosing Vite issues in SvelteKit templates easier (https://github.com/vitejs/vite/pull/5192 and https://github.com/vitejs/vite/pull/5193). Vite 2.7 is currently available in beta with additional fixes for SSR
To see all updates to Svelte and SvelteKit, check out the [Svelte](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md) and [SvelteKit changelog](https://github.com/sveltejs/kit/blob/master/packages/kit/CHANGELOG.md), respectively.
---
## Community Showcase
**Apps & Sites**
- [Tangent](http://tangentnotes.com/) is a clean and powerful notes app for Mac & Windows
- [The Pudding](https://pudding.cool/) is a digital publication that explains ideas debated in culture with visual essays - rebuilt in SvelteKit
- [Power Switcher](https://powerswitcher.axpo.com/) is an interactive overview of the development of the power supply in Switzerland, as energy sources migrate to cleaner sources
- [Sublive](https://sub.live/) is a new way of making music by connecting musicians all over the world with a low-latency and high-quality audio network
- [Vibify](https://www.vibify.me/) helps you find hidden playlists within your music using your Spotify listening history
- [Browse Marvel Unlimited by Year](https://marvel.geoffrich.net/) is a SvelteKit site to see what issues are available on Marvel Unlimited for a given year
- [Files](https://files.community/), a modern file explorer for Windows, has a new site rebuilt with SvelteKit
- [lil-hash](https://github.com/jackbow/lil-hash) is a simple URL shortener that produces easily rememberable and speakable shortened URLs
- [PWA Haven](https://github.com/ThaUnknown/pwa-haven) is a collection of small, fast, simple PWAs to replace native OS apps
- [DottoBit](https://dottobit.com/) is a multi-color 16-bit drawing program with URL sharing built-in
- [Former Fast Document for Print](https://github.com/zummon/former) is an invoice generator with beautiful designs, abilities for international languages and auto calculation
- [Helvetikon](https://github.com/noahsalvi/helvetikon) is a community maintained dictionary for the Swiss German language
- [Palitra App](https://palitra.app/) is a search-based color pallete generator
**Podcasts Featuring Svelte**
- [Svelte Radio](https://www.svelteradio.com/episodes/svelte-summit-is-coming-up-and-svelte-is-growing) dives into the tech behind the recently released Svelte Summit website and a bunch of other fun stuff!
- [PodRocket](https://podrocket.logrocket.com/rich-harris), LogRocket's podcast, talks Svelte with Rich Harris
- [PodRocket also dove deep](https://podrocket.logrocket.com/elderjs) into Elder.js with Nick Reese
- [Web Rush](https://webrush.io/episodes/episode-153-single-page-application-vs-multi-page-application-with-rich-harris) and Rich Harris talk about the differences between a SPA and MPA, what role the server rendering plays, what client side hydration is, and the state of modern tooling for developing an SPA or MPA
- [devtools.fm](https://devtools.fm/episode/15) talks with Rich Harris about developing engaging data visualizations and building the tools of tomorrow
**Educational Content**
- [Have Single-Page Apps Ruined the Web?](https://www.youtube.com/watch?v=860d8usGC0o) Rich Harris answers the controversial question at this year's Jamstack Conf
- [Svelte vs SvelteKit - What's The Difference?](https://www.youtube.com/watch?v=IKhtnhQKjxQ) LevelUpTuts provides a quick guide to explaining the relationship between the two projects. You can check out the rest of Scott Tolinski's guides to Svelte in his new series, ["Weekly Svelte"](https://www.youtube.com/playlist?list=PLLnpHn493BHF-Onm1MQgKC1psvW-rJuYi)
- [WebJeda's SvelteKit Hooks](https://www.youtube.com/watch?v=RarufLoEL08&list=PLm_Qt4aKpfKgzcTiMT2cgWGBDBIPK06DQ) series continues this month with Part 3 - Cookie Session Authentication
- [Writing Context Aware Styles in a Svelte App](https://www.ryanfiller.com/blog/tips/svelte-contex-aware-styles) is a guide to writing self-contained components that are able to dynamically adapt to their parents
- [A Beginners Guide to SvelteKit](https://www.sitepoint.com/a-beginners-guide-to-sveltekit/) takes a beginner-friendly look at both Svelte and SvelteKit and build out a simple web app showing profile pages of imaginary users
- [Svelte vs React: Ending the Debate](https://massivepixel.io/blog/svelte-vs-react/) is a historical take on the age-old argument
- [Svelte Snacks | Custom Events for Modal Actions](https://jeremydayslice.hashnode.dev/svelte-snacks-or-custom-events-for-modal-actions) walks through a solid implementation of Svelte's handy custom event system
- [What Svelte's accessibility warnings won't tell you](https://geoffrich.net/posts/svelte-a11y-limits/) explains how Svelte's a11y warnings work and why you shouldn't count on them to make your app accessible
**Libraries, Tools & Components**
- [svelte-adapter-azure-swa](https://github.com/geoffrich/svelte-adapter-azure-swa) is an adapter for Svelte apps that creates an Azure Static Web App, using an Azure function for dynamic server rendering
- [Inlang](https://docs.inlang.dev/getting-started/svelte-kit) is a localization and internationalization toolkit that now supports SvelteKit
- [svelte-translate-tools](https://github.com/noelmugnier/svelte-translate-tools) extract/generate/compile translation files for your Svelte App at build time
- [@egjs/svelte-infinitegrid](https://github.com/naver/egjs-infinitegrid/tree/master/packages/svelte-infinitegrid) lets you implement various grids composed of different card elements whose sizes vary
- [svelte-reactive-css-preprocess](https://github.com/srmullen/svelte-reactive-css-preprocess) makes it easier to update css variable values whenever your component state changes
- [Sveltegen](https://github.com/snuffyDev/sveltegen) is a CLI for simple and easy creation of actions, components, and routes
- [svelte-advanced-multistep-form](https://www.npmjs.com/package/svelte-advanced-multistep-form) helps to wrap form elements passing down styles to the component to be rendered, also it presents each form step in a ordered and stylish way
- [gQuery](https://github.com/leveluptuts/gQuery) is a GraphQL Fetcher & Cache for SvelteKit
- [date-picker-svelte](https://github.com/probablykasper/date-picker-svelte) is a date and time picker for Svelte
- [TwelveUI](https://twelveui.readme.io/reference/what-is-twelveui) is a Svelte component library with accessibility built-in
- [svelte-outclick](https://github.com/babakfp/svelte-outclick/) is a Svelte component that allows you to listen for clicks outside of an element, by providing you an outclick event
- [svelte-zero-api](https://github.com/ymzuiku/svelte-zero-api) lets you use SvelteKit APIs like client functions - with support for Typescript
- [svelte-recaptcha-v2](https://github.com/basaran/svelte-recaptcha-v2) is a Google reCAPTCHA v2 implementation for Svelte SPA, SSR and sveltekit static sites.
- [Svelte Body](https://github.com/ghostdevv/svelte-body) lets you apply styles to the body in routes - designed to work with SvelteKit and Routify.
- [svelte-debug-console](https://github.com/basaran/svelte-debug-console) is a debug.js implementation for Svelte SPA, SSR and sveltekit static sites that lets you see your debug statements in the browser.
- [SVEO](https://github.com/didier/sveo) is a dependency-free approach to declare metadata on SvelteKit pages
- [@svelte-drama/suspense](https://www.npmjs.com/package/@svelte-drama/suspense) is a Svelte component that implements the core idea of React's `<Suspense>`. Also check out [SWR for Svelte](https://www.npmjs.com/package/@svelte-drama/swr) to make refetching even easier.
- [sveltekit-adapter-browser-extension](https://github.com/antony/sveltekit-adapter-browser-extension) is an adapter for SvelteKit which turns your app into a cross-platform browser extension
Check out the community site [sveltesociety.dev](https://sveltesociety.dev/templates/) for more tools, templates, adders and adapters from across the Svelte ecosystem.
Looking for more Svelte goodness? Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs)!

@ -1,91 +0,0 @@
---
title: "What's new in Svelte: December 2021"
description: "Svelte Summit Fall 2021 Recap, Rich Harris joins Vercel, and Kevin goes full-time on Svelte Society"
author: Daniel Sandoval
authorURL: https://desandoval.net
---
With SvelteKit getting more and more stable each day, there's not much to cover in terms of code changes other than bug fixes... So, in this month's newsletter, we'll be covering Svelte Summit Fall 2021!
If you want to dive deep into the last month's worth of bug fixes, check out the [Svelte](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md) and [SvelteKit](https://github.com/sveltejs/kit/blob/master/packages/kit/CHANGELOG.md) changelogs, respectively.
## What happened at Svelte Summit?
If you missed Svelte Summit, you can watch the entire live stream on [YouTube](https://www.youtube.com/watch?v=1Df-9EKvZr0) and catch a recap in the [#svelte-summit channel on Discord](https://discord.gg/YmHcdnhu).
Here are the highlights:
- [Rich Harris](https://twitter.com/rich_harris) took us through a tour of Svelte's history and announced [his move to Vercel](https://vercel.com/blog/vercel-welcomes-rich-harris-creator-of-svelte) - where he will be helping maintain Svelte full-time! ([20:00](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=1200s))
- [Steph Dietz](https://twitter.com/steph_dietz_) explained how Svelte's simple abstractions makes it easy for beginners and experts alike to learn and use JavaScript - without the boilerplate ([29:00](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=1740s))
- [Kevin Bridges](https://twitter.com/kevinast) dove deep into Svelte's reactivity logic by visualizing it through `ReflectiveCounter` and showing how to "fine tune" it, as needed. A full "syllabus" for the presentation is available on [Kevin's site](https://wiibridges.com/presentations/ResponsiveSvelte/). ([42:55](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=2575s))
- [Mateo Morris](https://twitter.com/_mateomorris) launched [Primo](https://primo.af/), an all-in-one SvelteKit CMS to help build and manage static sites ([1:12:34](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=4354s))
- [Guillermo Rauch](https://vercel.com/about/rauchg) explained Vercel's commitment to Svelte, what it means to have Rich on the team, and what's coming next from the company... ([1:21:54](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=4914s))
- [Geoff Rich](https://twitter.com/geoffrich_) introduced various ways to modify motion and transitions within Svelte to be more accessible to all users of the web. Slides and a full transcription of the talk are available on [Geoff's site](https://geoffrich.net/posts/svelte-summit-2021/). ([1:32:30](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=5550s))
- [Dean Fogarty](https://df.id.au/) demoed a number of different use-cases for custom stores - transforming data to and from storage mechanisms within Svelte. Transcript and code is available on [Dean's GitHub](https://github.com/angrytongan/svelte-summit-2021). ([1:43:06](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=6186s))
- [Kellen Mace](https://twitter.com/kellenmace) shared how we can let content creators keep using WordPress, while leveraging Svelte on the frontend to provide a phenomenal user experience ([1:49:30](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=6570ss))
- [Ben Holmes](https://twitter.com/bholmesdev) explained the "islands" architecture and how 11ty + [Slinkity](https://slinkity.dev/) can bring these islands to any HTML template ([2:17:15](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=8235s))
- [Scott Tolinski](https://twitter.com/stolinski) shared the lessons learned from rewriting the React-based LevelUpTutorials in Svelte and "found developer bliss" ([3:16:35](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=11795s))
- [Svelte Sirens](https://sveltesirens.dev) was announced as the new Svelte community for women, non-binary and allies. Their first event was on November 29th - all future events can be found on [the Svelte Sirens website](https://sveltesirens.dev/events) ([3:50:45](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=13845s))
- [Rich Harris](https://twitter.com/rich_harris) discussed creating libraries with SvelteKit, better ways to link packages when developing, and how SvelteKit helps with modern JavaScript library development ([3:56:00](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=14160s))
- [Ken Kunz](https://twitter.com/kennethkunz) explained how finite state machines (and the svelte-fsm library) can make managing Svelte component states more... manageable. Examples from the talk are available on [Ken's GitHub](https://github.com/kenkunz/svelte-fsm/wiki/Examples). ([4:07:18](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=14838s))
- [Austin Crim](https://twitter.com/crim_codes) connected learning to code on the web to learning how to play an instrument. By giving learners early wins and introducing the fundamentals through real-world apps, learning Svelte (and the fundamentals underneath) doesn't have to be a chore ([4:21:50](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=15710s))
- [Jesse Skinner](https://twitter.com/JesseSkinner) brought our legacy apps into the future by explaining how to use (and reuse) Svelte components within React (and even jQuery!) projects ([4:32:30](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=16350s))
- [Jim Fisk](https://twitter.com/jimafisk) and [Stephanie Luz](https://stephanie-luz.medium.com/) introduced [Plenti](https://plenti.co/) and its theming tools to make building new Svelte sites much faster ([4:59:00](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=17940s))
- [Evyatar Alush](https://twitter.com/evyataral) helped us all make (and maintain) better forms using a powerful validation library called [Vest](https://github.com/ealush/vest) ([5:08:55](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=18535s))
- Dominik G. presented a fresh take on icon libraries - one that reduces the bundle size of applications and opens up the entire iconify library for use in any Svelte app ([5:30:04](https://www.youtube.com/watch?v=1Df-9EKvZr0&t=19804s))
Thanks to [Kevin](https://twitter.com/kevmodrome) and all the Svelte Society volunteers for pulling together such an amazing event! Excitingly, [Kevin announced](https://twitter.com/kevmodrome/status/1463151477174714373) after the event that he will now be working full-time on Svelte Society! You can check out all the talks, broken up into individual videos for convenience, in [this Svelte Society YouTube Playlist](https://www.youtube.com/playlist?list=PL8bMgX1kyZTg2bI9IOMgfBc8lrU3v2itt).
If you have feedback on the Svelte Summit, Kev is [looking for feedback on the Svelte subreddit](https://www.reddit.com/r/sveltejs/comments/qzgo3k/svelte_summit_feedback/) 👀
---
## Community Showcase
**Apps & Sites**
- [pixeldrain](https://github.com/Fornaxian/pixeldrain_web) is a free-to-use file sharing platform
- [LifeHash](http://lifehash.info/) generates beautiful visual hashes from Blockchain Commons
- [simple-cloud-music](https://github.com/dufu1991/simple-cloud-music) is a lightweight third-party NetEase cloud music player for modern browsers (likely only works on Chrome)
- [palette.rocks](https://palette.rocks/) is a color palette generator with contrast-checking built-in
- [Kadium](https://github.com/probablykasper/kadium) is an app for staying on top of YouTube channel uploads
- [Multi-Monitor Calculator](https://multimonitorcalculator.com/) is a tool for planning your multi-monitor setup
- [Your Home](https://yourhome.fb.com/) is an interactive overview of Facebook's privacy settings
- [Svelte Crush](https://svelte-crush.netlify.app/) is a Candy Crush style match-3 game
- [100.000 Corona deaths in Germany](https://twitter.com/h_i_g_s_c_h/status/1463767113563353089?s=20) is a visualization made for Spiegel Gesundheit
**Looking for a Svelte project to work on? Interested in helping make Svelte's presence on the web better?** Check out [the list of open issues](https://github.com/svelte-society/sveltesociety-2021/issues) if you'd like to contribute to the Svelte Society rewrite in SvelteKit.
**Videos, Blogs and Podcasts**
- [How To Make and Publish a Svelte Library](https://www.youtube.com/watch?v=_TymiadmPrc)
- [SvelteKit is now fully supported in WebContainers](https://blog.stackblitz.com/posts/sveltekit-supported-in-webcontainers/)
- [Introducing Svelte, and Comparing Svelte with React and Vue](https://joshcollinsworth.com/blog/introducing-svelte-comparing-with-react-vue)
- [Testing a Svelte app with Jest](https://www.roboleary.net/2021/11/18/svelte-app-testing-jest.html)
- [How to create a toast notification library package with SvelteKit](https://www.sarcevic.dev/blog/toasting-in-svelte)
- [Svelte training: Here you can learn Svelte](https://sustainablewww.org/principles/svelte-training-here-you-can-learn-svelte)
- [Introduction to Svelte Actions](https://blog.logrocket.com/svelte-actions-introduction/)
- [Enjoy making DAPPs using SvelteWeb3](https://chiuzon.medium.com/enjoy-making-dapps-using-svelteweb3-b78dfea1d902)
- [Svelte creator: Web development should be more fun](https://www.infoworld.com/article/3639521/svelte-creator-web-development-should-be-more-fun.html)
- [Svelte Radio: Rich Harris is now working full-time on Svelte 🤯](https://share.transistor.fm/s/d9b04961)
- [Web Rush: Svelte and Elder.js with Nick Reese](https://webrush.io/episodes/episode-158-svelte-and-elderjs-with-nick-reese)
- [Building SvelteKit applications with Serverless Redis](https://blog.upstash.com/svelte-with-serverless-redis)
**Libraries, Tools & Components**
- [svelte-cubed](https://github.com/Rich-Harris/svelte-cubed) is a Three.js component library for Svelte - created by Rich Harris for his presentation at Svelte Summit Fall 2021
- [svelte-fsm](https://github.com/kenkunz/svelte-fsm) is a tiny, simple, expressive, pragmatic Finite State Machine (FSM) library, optimized for Svelte
- [bromb](https://github.com/samuelstroschein/bromb) is a feedback widget for websites/web apps that is small and easy to integration/self-host
- [Spaper](https://github.com/Oli8/spaper) is a set of PaperCSS components for Svelte
- [svelte-intl-precompile](https://github.com/cibernox/svelte-intl-precompile) is an i18n library for Svelte that analyzes and compiles your translations at build time
- [svelte-preprocess-svg](https://github.com/svitejs/svelte-preprocess-svg) automatically optimizes inline svg in Svelte components for better performance and reduced file size
- [svelte-subcomponent-preprocessor](https://github.com/srmullen/svelte-subcomponent-preprocessor) allows you to write more than one component within a svelte file
- [svelte-pdfjs](https://github.com/gtm-nayan/svelte-pdfjs) is a crude implementation of a Svelte PDF viewer component
- [svelte-inview](https://github.com/maciekgrzybek/svelte-inview) is a Svelte action that monitors an element enters or leaves the viewport/parent element
- [sveltekit-adapter-wordpress-shortcode](https://github.com/tomatrow/sveltekit-adapter-wordpress-shortcode) is an adapter for SvelteKit which turns your app into a wordpress shortcode
- [svelte-websocket-store](https://github.com/arlac77/svelte-websocket-store) is a Svelte store with a websocket backend
- [Svelte Auto Form](https://github.com/leveluptuts/auto-form) is a fast and fun form library focused on ease of use, rather than flexibility.
- [set-focus](https://www.npmjs.com/package/@svackages/set-focus) is an Svelte action that will set focus on `<a>` or `<button>` elements as soon as they mount - useful for some experiences and testing
Got an idea for SvelteKit? Check out the new [GitHub Discussions](https://github.com/sveltejs/kit/discussions) in the Svelte repo. You can also join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs).
See you next ~~month~~ year!

@ -1,77 +0,0 @@
---
title: "What's new in Svelte: January 2022"
description: "Faster builds with SvelteKit and a much anticipated REPL feature"
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Happy new year, Svelte Community! Lots to share this month across Svelte, SvelteKit, Language Tools and the Showcase. Thanks to everyone who made 2021 a great year to use Svelte. Looking forward to the next one 🚀
## What's new in SvelteKit
- `@sveltejs/adapter-static` for SvelteKit now has a `precompress` option to make brotli compression of assets and pages easier to do out of the box ([#3079](https://github.com/sveltejs/kit/pull/3079))
- Concurrency mode in SvelteKit will now prerender pages in parallel ([#3120](https://github.com/sveltejs/kit/pull/3120)). It is enabled by default in `1.0.0-next.205` and later
- CSS is now automatically included before JS for improved page performance ([d13efe](https://github.com/sveltejs/kit/commit/d138efe21692f5925f1e89afc0a33f42d6a1a711))
- A new config option adds the ability to disable service worker registration to do your own custom registration ([#2988](https://github.com/sveltejs/kit/pull/2988))
- SSR route-splitting is here - breaking monolithic builds into smaller pieces for improved startup and routing performance ([#2931](https://github.com/sveltejs/kit/pull/2931))
- `request.origin/path/query` is now `request.url` - simplifying the config and page `load` functions ([#3126](https://github.com/sveltejs/kit/pull/3126))
- After the [update to Vite 2.7](https://github.com/sveltejs/kit/pull/3018), SvelteKit users are [reporting significant performance improvements](https://www.reddit.com/r/sveltejs/comments/rljhfc/sveltekit_massive_compiler_improvement_by/) and loading third-parties libraries in SSR has also been greatly improved
- SvelteKit server will now automatically restart when the config files is changed ([vite-plugin-svelte#237](https://github.com/sveltejs/vite-plugin-svelte/pull/237))
## Other new bits from `svelte/*`
- [Svelte 3.44.3](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md#3443) is out with a few bug fixes in the binding and loop code
- Svelte Language Tools has introduced support for the then/catch shorthands from Svelte 3.41 and TypeScript's "go to" functionality ([105.8.0 and later](https://github.com/sveltejs/language-tools/releases/tag/extensions-105.8.0))
- The Svelte REPL got a nice upgrade as well - letting you delete saved REPLs. Try it out by logging in at [svelte.dev/apps](https://svelte.dev/apps)
---
## Community Showcase
**Apps & Sites**
- [Discover Twitter Spaces](https://github.com/navneetsharmaui/discover-twitter-spaces) is a tool that helps you find the Twitter Spaces
- [Modern Fluid Typography Editor](https://github.com/codeAdrian/modern-fluid-typography-editor) helps create beautiful fluid typography using CSS clamp
- [Unnwhiteboard](https://github.com/AviKKi/unnwhiteboard) is a job board for companies (or teams) that don't do "whiteboard" interviews
- [Secret Santa](https://gitlab.com/arturoguzman/secret-santa-sveltekit) is a gift giving coordination app developed with easiness in mind
- [LogSnag](https://logsnag.com/) notifies you of your projects' events and provides you with a timeline to keep track of anything important that happens
- [Version 0.2 of Tangent](http://tangentnotes.com/Download), a Svelte-based note writing app, is now in beta
- [Intl Explorer](https://github.com/jesperorb/intl-explorer) is a tool for viewing output for all possible formatters for Intl
A lot of work this month has gone into migrating the Svelte main website and Svelte REPL to live in the https://github.com/sveltejs/sites repository - including a brand new homepage for [svelte.dev](https://svelte.dev/). Thanks to all the contributors who made this possible!
If you're looking for a fun SvelteKit project to work on, [you can contribute to the Svelte Society site rewrite](https://github.com/svelte-society/sveltesociety-2021/issues) 💅
**Learning and Listening**
_To Read_
- [Mutating Query Params in SvelteKit Without Page Reloads or Navigations](https://dev.to/mohamadharith/mutating-query-params-in-sveltekit-without-page-reloads-or-navigations-2i2b) by Mohamad Harith
- [Svelte for Reactaholics : A guide for React developers](https://www.100ms.live/blog/svelte-guide-for-react-developers) by Puru Vijay
- [Svelte's lifecycle methods can be used anywhere](https://geoffrich.net/posts/svelte-lifecycle-examples/) and [The many meanings of $ in Svelte](https://geoffrich.net/posts/svelte-$-meanings/) by Geoff Rich
- [Vercel and Svelte: A Perfect Match for Web Developers](https://thenewstack.io/vercel-and-svelte-a-perfect-match-for-web-developers/) by Darryl K. Taft
- [User-defined TailwindCSS Color Scheme with Svelte Stores](https://blog.dayslice.io/user-defined-tailwindcss-color-scheme-with-svelte-stores-ad80ca2cf038) by jeremy zaborowski
- [Ionic 6 + Svelte 🚀](https://medium.com/@raymondboswel/ionic-6-svelte-ae904caa82df) by Raymond Boswel
- [What happened in #Svelte language tools this year](https://twitter.com/dummdidumm_/status/1474158105395179525?t=ytj2K2Q52iD5-lNyLnQaAQ&s=19) by Simon H
_To Watch_
- [The Future of Svelte (Interview with Rich Harris)](https://www.youtube.com/watch?v=uQntFkK8Z54) by Lee Robinson, Director of Developer Relations at Vercel
- [Svelte is becoming the go-to framework](https://www.youtube.com/watch?v=fo6BKY2xR2w&t=1834s) for Obsidian plugin developers
- [Sveltekit WordPress Headless Blog](https://www.youtube.com/watch?v=c0UDVgjPxFw) by WebJeda
- [Getting started with SvelteKit](https://www.youtube.com/watch?v=i2suPKMPUFA) by Lihau Tan
- [Deploy a full-stack SvelteKit app on Cloudflare Pages](https://www.youtube.com/watch?v=Wc1_U6Dy5Tw) by 1nf
_To Listen To_
- [Syntax podcast: How To Do Things In Svelte](https://podcasts.apple.com/ca/podcast/how-to-do-things-in-svelte/id1253186678?i=1000544796072)
- [JS Party #205: So much Sveltey goodness (w/ Rich Harris)](https://changelog.com/jsparty/205)
**Libraries, Tools & Components**
- [svelte-headlessui](https://github.com/rgossiaux/svelte-headlessui) is an unofficial, complete Svelte port of the Headless UI component library
- [svelte-forms v2](https://chainlist.github.io/svelte-forms/) has been released - the author is [looking for feedback](https://www.reddit.com/r/sveltejs/comments/r6354j/svelteforms_v2_has_been_released/)
- [Percival](https://github.com/ekzhang/percival) is a declarative data query and visualization language
- [Svelte FlatList](https://github.com/snuffyDev/svelte-flatlist) is a mobile-friendly, simple, and customizable draggable menu
- [svelte-keyed](https://github.com/bryanmylee/svelte-keyed) is a writable derived store for objects and arrays
- [Svemix](https://github.com/svemix/svemix) is Remix for Svelte - providing server scripts inside your Svelte components/routes, which will be transformed into endpoints
Want to add something to the showcase? Need help bringing your next idea to life in Svelte? Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs).
See ya next month!

@ -1,67 +0,0 @@
---
title: "Accelerating Svelte's Development"
description: "Scaling the team, building partnerships, and growing the community"
author: Ben McCann
authorURL: https://www.benmccann.com/
---
[Svelte](/) is a frontend framework for building fast reactive web apps with less code. If youre new here, [check out the tutorial](/tutorial) or [examples](/examples) to get a feel for it.
Svelte was [launched 5 years ago](https://news.ycombinator.com/item?id=13069841) and has [come a long way in the time since](https://www.youtube.com/watch?v=YeY5M29-WcY). In 2021, as usage more than doubled, it was voted the [most loved](https://insights.stackoverflow.com/survey/2021#section-most-loved-dreaded-and-wanted-web-frameworks) framework with the [most satisfied](https://2020.stateofjs.com/en-US/technologies/front-end-frameworks/) developers in a pair of surveys. Alongside high-profile companies like The New York Times, Apple, Spotify, Square, Rakuten, Bloomberg, Reuters, Ikea, Brave, and countless others, Svelte is used to power everything from hobby projects to embedded systems interfaces.
To help developers build fully-featured applications with Svelte without worrying about the hard parts, weve been developing the [SvelteKit](https://kit.svelte.dev/) application framework. Were moving quickly towards a [stable 1.0 release](https://github.com/sveltejs/kit/issues?q=is%3Aopen+is%3Aissue+milestone%3A1.0) with the help of early adopters who have already downloaded SvelteKit almost one million times.
## Scaling the team
Rich Harris, Sveltes creator, has [joined Vercel to work on Svelte full-time](https://vercel.com/blog/vercel-welcomes-rich-harris-creator-of-svelte). Were incredibly excited to have Richs level of involvement in Svelte increase even more and have him steward Svelte into the future.
Svelte has been made possible by the work of a large, dedicated community. Svelte has added numerous core maintainers over the course of the pandemic, including three this past week. In alphabetical order:
- [benmccann](https://github.com/benmccann) - primary maintainer of SvelteKit for much of 2021
- [bluwy](https://github.com/bluwy) - major contributor across SvelteKit, vite-plugin-svelte, and Vite
- [dominikg](https://github.com/dominikg) - creator of vite-plugin-svelte
- [dummdidumm](https://github.com/dummdidumm) - maintainer of language-tools, which includes the VS Code extension and `svelte-check`
- [ehrencrona](https://github.com/ehrencrona) - contributor to SvelteKit and uses Svelte at work
- [geoffrich](https://github.com/geoffrich) - has driven efforts to improve the accessibility of the Svelte site and documentation
- [GrygrFlzr](https://github.com/GrygrFlzr) - holds a unique status as a maintainer of both SvelteKit and Vite
- [Halfnelson](https://github.com/Halfnelson) - creator of svelte-native
- [ignatiusmb](https://github.com/ignatiusmb) - regular SvelteKit contributor especially to TypeScript support
- [jasonlyu123](https://github.com/jasonlyu123) - maintainer of language-tools, which includes the VS Code extension and `svelte-check`
- [kaisermann](https://github.com/kaisermann) - creator of svelte-preprocess
- [RedHatter](https://github.com/RedHatter) - creator of Svelte Devtools
- [rixo](https://github.com/rixo) - creator of svelte-hmr
Svelte began accepting donations via [OpenCollective](https://opencollective.com/svelte) last year and has now had over $60,000 donated to-date with [Cohere](https://cohere.ai/) giving $10,000 just today. We hope that these funds will allow existing maintainers to spend more time on Svelte or that the funds could otherwise support Svelte on a part-time or contract basis, which we will continue to investigate.
## Partnerships
Multiple major cloud vendors are stepping up to make deploying SvelteKit applications anywhere a seamless experience. As a result of Richs new job, SvelteKit will soon run on [Vercel Edge Functions](https://vercel.com/features/edge-functions). Netlify has made [big contributions](https://github.com/sveltejs/kit/pull/2113) to the SvelteKit Netlify adapter and also [updated](https://github.com/dependents/node-precinct/pull/88) their zip-it-and-ship-it tool to better support SvelteKit. The recent [Cloudflare Pages launch](https://blog.cloudflare.com/cloudflare-pages-goes-full-stack/) featured SvelteKit as a day one partner via a [new adapter](https://github.com/sveltejs/kit/tree/master/packages/adapter-cloudflare) written by Svelte maintainers [pngwn](https://twitter.com/evilpingwin) and [lukeed](https://twitter.com/lukeed05), the latter of whom joined Cloudflare in 2021. [Begin](https://begin.com) created a [SvelteKit adapter](https://github.com/architect/sveltekit-adapter) for [Architect](https://arc.codes) apps. And community members have [contributed adapters](https://sveltesociety.dev/components#adapters) for environments such as Firebase and Deno, showcasing SvelteKits ability to run wherever JavaScript does.
Weve also been working closely with the [Vite](https://vitejs.dev) team to iron out SSR issues uncovered by SvelteKit users. Vite is the build tool that makes the SvelteKit developer experience possible, and thanks to hard work from a contributor base that includes representatives of multiple frameworks, recent releases have solved almost all the issues weve been tracking as SvelteKit 1.0 release blockers.
## A growing community
[SvelteSociety](https://sveltesociety.dev/) just hosted the [4th Svelte Summit](https://sveltesummit.com/) — [read a summary here](https://svelte.dev/blog/whats-new-in-svelte-december-2021#what-happened-at-svelte-summit) — and Kevin Åberg Kultalahti is [going full-time to lead SvelteSociety](https://twitter.com/kevmodrome/status/1463151477174714373). In addition to hosting Svelte Summit, Kevin and SvelteSociety host and manage the [Svelte Radio podcast](https://www.svelteradio.com/), the [SvelteSociety YouTube channel](https://www.youtube.com/SvelteSociety), and the [Svelte subreddit](https://www.reddit.com/r/sveltejs). SvelteSociety has become the home of all things related to the Svelte community, with the sveltejs/community and sveltejs/integrations repos being retired in favor of [sveltesociety.dev](https://sveltesociety.dev/), which has been redesigned and rebuilt in SvelteKit. In October [Brittney Postma](https://github.com/brittneypostma), [Willow aka GHOST](https://ghostdev.xyz), [Steph Dietz](https://github.com/StephDietz), and [Gen Ashley](https://twitter.com/coderinheels) founded [Svelte Sirens](https://sveltesirens.dev/), a group for women & non-binary community members and their allies.
Hundreds of developers join the Svelte Discord every week to chat about Svelte. You may have noticed that, as of recently, some members of the server have purple names. These are people with the ambassadors role, which was created to recognise some of the communitys most valued members and help manage the demands of a rapidly growing community. Svelte ambassadors are people who are well known for their helpfulness and contributions and for upholding Sveltes reputation as a friendly, welcoming community, and were deeply grateful for their involvement. The initial ambassadors in alphabetical order are:
- [babichjacob](https://github.com/babichjacob)
- [brady fractal](https://github.com/FractalHQ)
- [brittney postma](https://github.com/brittneypostma)
- [d3sandoval](https://github.com/d3sandoval)
- [geoffrich](https://github.com/geoffrich)
- [kev](https://github.com/kevmodrome)
- [puru](https://github.com/PuruVJ)
- [rainlife](https://github.com/stephane-vanraes)
- [rmunn](https://github.com/rmunn)
- [stolinski](https://github.com/stolinski)
- [swyx](https://github.com/sw-yx)
- [theo](https://github.com/theo-steiner)
Were also testing out [GitHub discussions on SvelteKit](https://github.com/sveltejs/kit/discussions) and may bring this to other repos in the Svelte organization if feedback is positive.
## Things to watch
SvelteKit is continuing to progress towards 1.0 and, in just the past week, we have added major features like [improved client-only rendering](https://github.com/sveltejs/kit/pull/2804), [routing hooks](https://github.com/sveltejs/kit/pull/3293), and [the ability to pass data from child components to layouts](https://github.com/sveltejs/kit/pull/3252) (e.g. to support easier management of `<meta>` tags). We're currently working on a number of other high priority items such as discussing API designs for features like streaming and file uploads and contributing to the upcoming Vite 2.8 release.
While a lot of effort has been going into SvelteKit recently, we continue to progress the entire ecosystem. [Svelte 3.46.0](https://github.com/sveltejs/svelte/blob/master/CHANGELOG.md#3460) was one of our biggest releases in awhile with two major new features added: [constants in markup](https://github.com/sveltejs/rfcs/blob/master/text/0007-markup-constants.md) and [style directives](https://github.com/sveltejs/rfcs/blob/master/text/0008-style-directives.md).
Svelte and SvelteKits trajectories have been accelerated by the numerous investments above and there will be many more updates to come — subscribe to the [blog](/blog) via [RSS](https://svelte.dev/blog/rss.xml) or check monthly to be the first to get them.

@ -1,106 +0,0 @@
---
title: "What's new in Svelte: February 2022"
description: "Rapid-fire releases across Svelte, SvelteKit and the community"
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Happy February, everyone! Over the last month or so, we've seen Svelte and SvelteKit [develop at rapid speed](accelerating-sveltes-development), new community rules across the [Reddit](https://www.reddit.com/r/sveltejs/comments/s9n8ou/new_rules/), [GitHub](https://github.com/sveltejs/community/blob/main/CODE_OF_CONDUCT.md) and [Discord](https://discord.com/channels/457912077277855764/831611707667382303/935264550436102315), and quite a few amazing apps, tutorials and libraries.
Let's take a look...
## Highlights from the Svelte changelog
- **3.45.0** brought a [new a11y warning `a11y-no-redundant-roles`](https://svelte.dev/docs#accessibility-warnings-a11y-no-redundant-roles), destructuring and caching fixes
- **3.46.0** added the much requested [`{@const}` tag](https://svelte.dev/docs#template-syntax-const) and [`style:` directive](https://svelte.dev/docs#template-syntax-element-directives-style-property)
- Check out **3.46.1 - 3.46.3** for fixes to the `{@const}` tag and `style:` directive, along with a number of fixes to animations
- [AST output is now available in the Svelte REPL](https://svelte.dev/repl/hello-world)
## What's new in SvelteKit
- `inlineStyleThreshold` allows you to specify where inline stylesheets are inserted into the page ([Docs](https://kit.svelte.dev/docs/configuration#inlinestylethreshold), [#2620](https://github.com/sveltejs/kit/pull/2620))
- `beforeNavigate`/`afterNavigate` lifecycle functions lets you add functionality before or after a page navigation ([Docs](https://kit.svelte.dev/docs/modules#$app-navigation), [#3293](https://github.com/sveltejs/kit/pull/3293))
- Platform context can now be passed from adapters ([Docs](https://kit.svelte.dev/docs/adapters#supported-environments-platform-specific-context), [#3429](https://github.com/sveltejs/kit/pull/3429))
- Hooks now have an `ssr` parameter in `resolve` to make it easier to skip SSR, when needed ([Docs](https://kit.svelte.dev/docs/hooks#handle), [#2804](https://github.com/sveltejs/kit/pull/2804))
- `$page.stuff` provides a mechanism for pages to pass data 'upward' to layouts ([Docs](https://kit.svelte.dev/docs/loading#input-stuff), [#3252](https://github.com/sveltejs/kit/pull/3252))
- Fallthrough routes let you specify where to route when an route can't be loaded ([Docs](https://kit.svelte.dev/docs/routing#advanced-routing-fallthrough-routes), [#3217](https://github.com/sveltejs/kit/pull/3217))
**New configs**
- Content Security Policy (CSP) is now supported for increased security when using inline javascript or stylesheets ([Docs](https://kit.svelte.dev/docs/configuration#csp), [#3499](https://github.com/sveltejs/kit/pull/3499))
- `kit.routes` config allows you to customise public/private modules during build ([Docs](https://kit.svelte.dev/docs/configuration#routes), [#3576](https://github.com/sveltejs/kit/pull/3576))
- `prerender.createIndexFiles` config lets you prerender index.html files as their subfolder's name ([Docs](https://kit.svelte.dev/docs/configuration#prerender), [#2632](https://github.com/sveltejs/kit/pull/2632))
- HTTP methods can now be overridden using `kit.methodOverride` ([Docs](https://kit.svelte.dev/docs/routing#endpoints-http-method-overrides), [#2989](https://github.com/sveltejs/kit/pull/2989))
**Config changes**
- `config.kit.hydrate` and `config.kit.router` are now nested under `config.kit.browser` ([Docs](https://kit.svelte.dev/docs/configuration#browser), [3578](https://github.com/sveltejs/kit/pull/3578))
**Breaking change**
- use `Request` and `Response` objects in endpoints and hooks ([#3384](https://github.com/sveltejs/kit/pull/3384))
---
## Community Showcase
**Apps & Sites**
- [timb(re)](https://paullj.github.io/timb) is a live music programming environment
- [Music for Programming](https://musicforprogramming.net/latest/) is a series of mixes intended for listening while `${task}` to focus the brain and inspire the mind
- [Team Tale](https://teamtale.app/) allows two authors to write the same story in a tag-team sort of fashion
- [Puzzlez](https://www.puzzlez.io/) is an online place to play Sudoku and Wordle
- [Closed Caption Creator](https://www.closedcaptioncreator.com/) makes it easy to add subtitles to your video on Windows, Mac and Google Chrome
- [SC3Lab](https://sc3-lab.netlify.app/) is a code generator for experimenting with svelte-cubed and three.js
- [Donkeytype](https://github.com/0ql/Donkeytype) is a minimalistic and lightweight typingtest inspired by Monkeytype.
- [Above](https://above.silas.pro/) is a visual routine timer built for the ADHD/autistic mind
- [base.report](https://base.report/) is a modern research platform for serious investors
- [String](https://string.kampsy.xyz/) turns your Phone into a secure portable audio recorder, making it easy to capture and share personal notes, family moments, classroom lectures, and more
- [The Raytracer Challenge REPL](https://github.com/jakobwesthoff/the_raytracer_challenge_repl) provides a live editor interface to configure a raytraced scene and render it live in any modern browser
- [awesome-svelte-kit](https://github.com/janosh/awesome-svelte-kit) is a list of awesome examples of SvelteKit in the wild
- [Map Projection Explorer](https://www.geo-projections.com/) lets you explore different map projections and explains their differences
- [Rubiks](https://github.com/MeharGaur/rubiks) is a Rubik's Cube simulator
- [Pianisto](https://pianisto.net/) is a working piano made with SVG, ToneJS and a lot of patience
Want to work on a SvelteKit site with others, [try contributing to the Svelte Society site](https://github.com/svelte-society/sveltesociety-2021/issues)!
**Learning and Listening**
_To Read_
- [Accelerating Svelte's Development](https://svelte.dev/blog/accelerating-sveltes-development) by Ben McCann
- [Storybook for Vite](https://storybook.js.org/blog/storybook-for-vite/)
- [Let's learn SvelteKit by building a static Markdown blog from scratch](https://joshcollinsworth.com/blog/build-static-sveltekit-markdown-blog) by Josh Collinsworth
- [Building an iOS app with Svelte, Capacitor and Firebase](https://harryherskowitz.com/2022/01/05/tapedrop-app.html) by Harry Herskowitz
- [Mutating Query Params in SvelteKit Without Page Reloads or Navigations](https://dev.to/mohamadharith/mutating-query-params-in-sveltekit-without-page-reloads-or-navigations-2i2b) and [Workaround for Bubbling Custom Events in Svelte](https://dev.to/mohamadharith/workaround-for-bubbling-custom-events-in-svelte-3khk) by Mohamad Harith
- [How to build a full stack serverless application with Svelte and GraphQL](https://dev.to/shadid12/how-to-build-a-full-stack-serverless-application-with-svelte-graphql-and-fauna-5427) by Shadid Haque
- [How to Deploy SvelteKit Apps to Github Pages](https://sveltesaas.com/articles/sveltekit-github-pages-guide/)
- [Creating a dApp with SvelteKit](https://anthonyriley.org/2021/12/31/creating-a-dapp-with-sveltekit/) by Anthony Riley
- [Comparing Svelte Reactivity Options](https://opendirective.net/2022/01/06/comparing-svelte-reactivity-options/) by Steve Lee
_To Watch_
- [Integrating Storybook with SvelteKit](https://www.youtube.com/watch?v=Kc1ULlfyUcw) and [Integrating FaunaDB with Svelte](https://www.youtube.com/watch?v=zaoLZc76uZM) by the Svelte Sirens
- [SvelteKit Crash Course Tutorial](https://www.youtube.com/watch?v=9OlLxkaeVvw&list=PL4cUxeGkcC9hpM9ARM59Ve3jqcb54dqiP) by The Net Ninja
- [Svelte for Beginners](https://www.youtube.com/watch?v=BrkrOjknC_E&list=PLA9WiRZ-IS_ylnMYxIFCsZN6xVVSvLuHk) by Joy of Code
- [SvelteKit For Beginners | Movie App Tutorial](https://www.youtube.com/watch?v=ydR_M0fw9Xc) by Dev Ed
- [SvelteKit $app/stores](https://www.youtube.com/watch?v=gBPhr1xbgaQ) by lihautan
- [Sveltekit - Get All Routes/Pages](https://www.youtube.com/watch?v=Y_NE2R3HuOU) by WebJeda
_To Listen To_
- [New Year, New Svelte!?](https://share.transistor.fm/s/36212cdc) from Svelte Radio
- [So much Sveltey goodness (featuring Rich Harris)](https://changelog.com/jsparty/205) from JS Party
- [The Other Side of Tech: A Documentarian Perspective (with Stefan Kingham)](https://codingcat.dev/podcast/2-4-the-other-side-of-tech-a-documentarian-perspective) from Purrfect.dev
**Libraries, Tools & Components**
- [threlte](https://github.com/grischaerbe/threlte) is a three.js component library for Svelte
- [svelte-formify](https://github.com/nodify-at/svelte-formify) is a library to manage and validate forms that uses decorators to define validations
- [gQuery](https://github.com/leveluptuts/gQuery) is a GraphQL Fetcher & Cache for Svelte Kit
- [Unlock-protocol](https://github.com/novum-insights/sveltekit-unlock-firebase) is an integration to help login with MetaMask, Firebase, and paywall customers
- [AgnosticUI](https://github.com/AgnosticUI/agnosticui) is a set of UI primitives that start their lives in clean HTML and CSS
- [Vitebook](https://github.com/vitebook/vitebook) is a fast and lightweight alternative to Storybook that's powered by Vite
- [SwyxKit](https://swyxkit.netlify.app/) is an opinionated blog starter for SvelteKit + Tailwind + Netlify. Refreshed for 2022!
- [svelte-themes](https://github.com/beynar/svelte-themes) is an abstraction for themes in your SvelteKit app
- [svelte-transition](https://www.npmjs.com/package/svelte-transition) is a Svelte component to make using CSS class based transitions easier - ideally suited for use with TailwindCSS
- [Svelte Inview](https://www.npmjs.com/package/svelte-inview) is a Svelte action that monitors an element enters or leaves the viewport/parent element
- [svelte-inline-compile](https://github.com/DockYard/svelte-inline-compile) is a babel transform that allows for a much more pleasant experience when testing svelte components using Jest and `@testing-library/svelte`
- [@feltcoop/svelte-mutable-store](https://github.com/feltcoop/svelte-mutable-store) is a Svelte store for mutable values with an `immutable` compiler option
- [headless-svelte-ui](https://www.npmjs.com/package/@bojalelabs/headless-svelte-ui) is a group of headless components that can be used in building Svelte Apps.
Did we miss something? Need help bringing your next idea to life in Svelte? Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs).
See ya next month!

@ -1,87 +0,0 @@
---
title: "What's new in Svelte: March 2022"
description: "Svelte Summit Spring is coming... and page endpoints are here!"
author: Daniel Sandoval
authorURL: https://desandoval.net
---
Just announced: [Svelte Summit Spring](https://www.sveltesummit.com/) will be taking place on April 30, 2022. The 5th Virtual Svelte Conference is [looking for speakers](https://www.sveltesummit.com/#speakers) and [sponsors](https://www.sveltesummit.com/sponsors)... so it's time to dust off those proposals!
Also, some long-requested features were added to SvelteKit this month... including page endpoints! This change in how the `load` function works makes it easier to fetch data required for basic pages, redirect from POST responses and handle 404s and other errors.
More on that and other new features and fixes below!
## What's new in SvelteKit
- The docs are now searchable and multipage with type definitions and hoverable code examples - Check them out at [kit.svelte.dev/docs](https://kit.svelte.dev/docs/)
- Page endpoints significantly decrease the boilerplate needed when loading a page ([Issue](https://github.com/sveltejs/kit/issues/3532), [PR](https://github.com/sveltejs/kit/pull/3679), [Docs](https://kit.svelte.dev/docs/routing#endpoints-page-endpoints))
- Application versioning and update detection support lets you determine what to do when a route fails to load after an app update ([Issue](https://github.com/sveltejs/kit/issues/87), [PR](https://github.com/sveltejs/kit/pull/3412), [Docs](https://kit.svelte.dev/docs/configuration#version))
- A new option in `npm init svelte@next` will now set up Playwright automatically for testing ([PR](https://github.com/sveltejs/kit/pull/4056))
**Breaking Changes**
- The `target` option is no longer available. Instead, the `init` script hydrates its `parentNode` ([#3674](https://github.com/sveltejs/kit/pull/3674))
- App-level types now live in the `App` namespace which allows you to type global types like `Stuff` or `Session` ([#3670](https://github.com/sveltejs/kit/pull/3670))
- `JSONString` is now `JSONValue` ([#3683](https://github.com/sveltejs/kit/pull/3683))
- `createIndexFiles` has been removed — it is now controlled by the `trailingSlash` option ([#3801](https://github.com/sveltejs/kit/pull/3801))
- SvelteKit will no longer exclude root-relative external links from prerendering, which will cause 404s if these URLs are intended to be served by a separate app. Use a custom [`prerender.onError`](https://kit.svelte.dev/docs/configuration#prerender) handler if you need to ignore them ([#3826](https://github.com/sveltejs/kit/pull/3826))
## New in Language Tools
- Accessing properties in markups has been improved in the Svelte language tools ([105.12.0](https://github.com/sveltejs/language-tools/releases/tag/extensions-105.12.0)) - working around some known issues with autocomplete ([#538](https://github.com/sveltejs/language-tools/issues/538) / [#1302](https://github.com/sveltejs/language-tools/issues/1302))
---
## Community Showcase
**Apps & Sites**
- [SvelteStorm](https://github.com/open-source-labs/SvelteStorm) is specifically tailored to provide all of the essential tools a Svelte developer needs to build a Svelte application
- [Supachat](https://github.com/Lleweraf/supachat) is a real-time chat app using Svelte and Supabase
- [Radicle](https://radicle.xyz/) is a peer-to-peer stack for building software together
- [The Making Known](https://the-making-known.com/) is a narrated encounter with posters designed by the Nazi German government to communicate with the occupied nations of Belgium, France, and Luxembourg during the Second World War
- [Svelte Kanban](https://github.com/V-Py/svelte-kanban) is a simple Svelte Kanban made in pure CSS
- [fngrng](https://github.com/nvlgzr/fngrng) is a typing trainer focussed on accuracy over speed
- [Generative grids](https://svelte.dev/repl/873988ce33db43f097c0ca69df57b3ac?version=3.46.4) is a neat little generative SVG grid in a Svelte REPL, with randomly generated color palettes and shapes
- [LifeHash](https://github.com/BlockchainCommons/lifehash.info) is a method of hash visualization that creates beautiful, deterministic icons
- [TypedWebhook.tools](https://typedwebhook.tools/) is a webhook testing tool for checking payloads, with automatic type generation
- [Speedskating](https://github.com/spiegelgraphics/speedskating) is an animation widget to show olympic speedskating runs. Built with Svelte, D3 and regl
- [Web tail](https://github.com/mishankov/web-tail) is a web application to view lines from file on local system or on remote server
Want to work on a SvelteKit site with others? [Contribute to the Svelte Society site](https://github.com/svelte-society/sveltesociety.dev/issues)!
**Learning Resources**
_To Read_
- [Svelte Components as Web Components](https://medium.com/@yesmeno/svelte-components-as-web-components-b400d1253504) by Matias Meno
- [Simple Svelte Routing with Reactive URLs](https://bjornlu.com/blog/simple-svelte-routing-with-reactive-urls) by Bjorn Lu
- [Leveling Up my Sveltekit / Sanity.io Blog Content with Featured Videos and Syntax Highlighting](https://ryanboddy.net/level-up-blog) by Ryan Boddy
- [How This Blog Makes the Most of GitHub](https://paullj.github.io/posts/how-this-blog-makes-the-most-of-github/) by paullj
- [FullStack JWT Auth: Introducing SvelteKit](https://dev.to/sirneij/fullstack-jwt-introducing-sveltekit-3jcn) by John Idogun
- [Svelte-Cubed: Adding Motion to 3D Scenes](https://dev.to/alexwarnes/svelte-cubed-adding-motion-to-3d-scenes-51lo) by Alex Warnes
- [Creating a RSS feed with Sanity and Svelte Kit](https://ghostdev.xyz/posts/creating-a-rss-feed-with-sanity-and-svelte-kit) by GHOST
- [How to use Svelte's style directive](https://geoffrich.net/posts/style-directives/) by Geoff Rich
- [SvelteKit and the "Client pattern"](https://retro.cloud/sveltekit-and-the-client-pattern/) by Julian Laubstein
_To Watch_
- [~~Shadow~~ Page Endpoints In Svelte Kit - Weekly Svelte](https://www.youtube.com/watch?v=PoYPZT7ruqI) by LevelUpTuts
- [Testing For Beginners (Playlist)](https://www.youtube.com/watch?v=y53wwdBr5AI&list=PLA9WiRZ-IS_z7KpqhPELfEMbhAGRwZrzn) by Joy of Code
- [KitQL - The native SvelteKit library for GraphQL](https://www.youtube.com/watch?v=6pH4fnFN70w) by Jean-Yves COUËT
**Libraries, Tools & Components**
- [gosvelte](https://github.com/sachinbhutani/gosvelte) is a proof of concept to serve Svelte-generated pages on GoLang HTTP server with server data being sent as props to svelte components
- [svelte-ethers-store](https://www.npmjs.com/package/svelte-ethers-store) uses the ethers.js library as a collection of readable Svelte stores for Svelte, Sapper or SvelteKit
- [Fluid Grid](https://fluid-grid.com/) is a CSS grid system for future web
- [stirstack](https://github.com/seeReadCode/stirstack) is an opinionated framework that combines Svelte.js, TailwindCSS, InertiaJS and Ruby on Rails
- [OATHqr](https://codeberg.org/vhs/oathqr) helps users create security credentials for use with 2FA/MFA and other OATH-enabled apps. Use it to generate scannable QR codes for one-time password authenticator apps such as Aegis or YubiKey
- [svelte-GridTiles](https://github.com/honeybeeSunshine/svelte-GridTiles) is a drag and drop resizable tiles library built on a responsive grid
- [Miscellaneous Svelte Components](https://github.com/alex-knyaz/Miscellaneous-svelte-components/) is a collection of miscellaneous svelte components alex-knyaz often use in my projects
- [walk-and-graph-svelte-components](https://github.com/j2l/walk-and-graph-svelte-components) is a CLI node script to walk svelte and js files, to draw a beautiful JPG of your dependencies aka "imports"
- [Felte](https://www.npmjs.com/package/felte) is a simple to use form library for Svelte
- [svelte-use-tooltip](https://github.com/untemps/svelte-use-tooltip) is a Svelte action to display a tooltip
- [persistent-svelte-store](https://github.com/omer-g/persistent-svelte-store) is a generic persistent writable store, built from scratch in TypeScript according to the Svelte store contract
What'd we miss? Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs) to continue the conversation.
See y'all next month!

@ -1,104 +0,0 @@
---
title: "What's new in Svelte: April 2022"
description: "Goodbye fallthrough routes, hello param validators!"
author: Daniel Sandoval
authorURL: https://desandoval.net
---
This month, we felt a shift in the way SvelteKit handles page properties. The last holdout of the use-cases that required fallthrough routes, validating parameter properties, has been replaced by a more specific solution.
More on that, and what else is new in Svelte, as we dive in...
## What's new in SvelteKit
- Param matchers allow you to check if a url parameter matches before rendering a page - replacing the need for fallthrough routes for this purpose ([Docs](https://kit.svelte.dev/docs/routing#advanced-routing-matching), [#4334](https://github.com/sveltejs/kit/pull/4334))
- Explicit redirects can now be handled directly from endpoints ([#4260](https://github.com/sveltejs/kit/pull/4260))
- `svelte-kit sync` ([#4182](https://github.com/sveltejs/kit/pull/4182)), TypeScript 4.6 ([#4190](https://github.com/sveltejs/kit/pull/4190)) and Vite 2.9 were released - adding non-blocking dependency optimization and experimental CSS source maps in dev mode as well as a number of bug fixes contributed by the SvelteKit team ([#4468](https://github.com/sveltejs/kit/pull/4468))
**New Config Options**
- `outDir` fixes path issues in monorepos and other situations where the desired output directory is outside the project directory ([Docs](https://kit.svelte.dev/docs/configuration#outdir), [#4176](https://github.com/sveltejs/kit/pull/4176))
- `endpointExtensions` prevents files other than .js and .ts files from being treated as endpoints, unless you specify endpointExtensions ([Docs](https://kit.svelte.dev/docs/configuration#endpointextensions), [#4197](https://github.com/sveltejs/kit/pull/4197))
- `prerender.default` lets you prerender every page without having to write `export const prerender = true` in every page file ([Docs](https://kit.svelte.dev/docs/configuration#prerender), [#4192](https://github.com/sveltejs/kit/pull/4192))
**Breaking Changes**
- Fallthrough routes have been removed. For migration tips, check out the PR ([#4330](https://github.com/sveltejs/kit/pull/4330))
- `tabindex="-1"` is only added to `<body>` during navigation ([#4140](https://github.com/sveltejs/kit/pull/4140) and [#4184](https://github.com/sveltejs/kit/pull/4184))
- Adapters are now required to supply a `getClientAddress` function ([#4289](https://github.com/sveltejs/kit/pull/4289))
- `InputProps` and `OutputProps` can now be typed separately in generated `Load` ([#4305](https://github.com/sveltejs/kit/pull/4305))
- The `\$` character is no longer allowed in dynamic parameters ([#4334](https://github.com/sveltejs/kit/pull/4334))
- `svelte-kit package` has been marked as experimental so changes to it after Kit 1.0 will not be considered breaking ([#4164](https://github.com/sveltejs/kit/pull/4164))
## New across the Svelte ecosystem
- Svelte: Lots of new types for TypeScript and Svelte plugin users - including `style:` directives and Svelte Actions (**3.46.4** and **3.46.5**)
- Language Tools: Svelte project files are now importable/findable through references without having them imported in a TS file ([105.13.0](https://github.com/sveltejs/language-tools/releases/tag/extensions-105.13.0))
- Language Tools: Region folding is now supported in html with `<!--#region-->`/`<!--#endregion-->` ([105.13.0](https://github.com/sveltejs/language-tools/releases/tag/extensions-105.13.0))
---
## Community Showcase
**Apps & Sites built with Svelte**
- [Launcher](https://launcher.team/) is an open-source app launcher powered by SvelteKit, Prisma, and Tailwind
- [Paaster](https://paaster.io/) is a secure by default end to end encrypted pastebin built with Svelte, Vite, Typescript, Python, Starlette, rclone & Docker.
- [Simple AF Video Converter](https://github.com/berlyozzy/Simple-AF-Video-Converter) is an Electron wrapper around ffmpeg.wasm to make converting videos between formats easier
- [Streamchaser](https://github.com/streamchaser/streamchaser) seeks to simplify movie, series and documentary search through a centralized entertainment technology platform
- [Svelte Color Picker](https://github.com/V-Py/svelte-material-color-picker) is a simple color picker made with Svelte
- [ConcertMash](https://github.com/mcmxcdev/ConcertMash) is a small website that interacts with the Spotify API and generates new playlists based on the upcoming concerts you're attending
- [Modulus](https://modulus.vision/) is a Design+Code Think Tank conceived with the main mission to evolve design and technology
- [Multiply](https://www.multiply.us/) is an integrated PR and Social agency moving at the speed of culture
- [yia!](https://www.yia.co.nz/) is a Young Innovator Award competition in New Zealand
- [Write to Russia](https://www.writetorussia.org/index) is a community email writing platform to communicate with public `.ru` email addresses
- [Markdown Playground](https://github.com/Petros-K/markdown-playground) is an online playground dedicated for your markdown experiments.
- [RatherMisty](https://rathermisty.com/) is a no frills weather app with weather data from Open-Meteo
- [Minecraft Profile Pic (MCPFP)](https://github.com/MauritsWilke/mcpfp) is a site to generate Minecraft profile pictures with ease
- [WebGL Fluid Simulation](https://github.com/jpaquim/svelte-webgl-fluid-simulation) is a configurable fluid simulation built with Svelte and WebGL
- [This @NobelPeaceOslo exhibition](https://twitter.com/perbyhring/status/1504754949791621120) was built using printed graphics, projected motion graphics, particle animations and generative sound design
Itching to contribute to a modern SvelteKit website? [Help build the Svelte Society site](https://github.com/svelte-society/sveltesociety.dev/issues)!
**Learning Resources**
_To Attend_
- [Svelte Summit: Spring](https://www.sveltesummit.com/) will take place on April 30, 2022! Join us for the 5th virtual Svelte conference on [YouTube](https://www.sveltesummit.com/) and Discord 🍾
_To Read_
- [Svelte(Kit) TypeScript Showcase + general TypeScript tips](https://github.com/ivanhofer/sveltekit-typescript-showcase) by Hofer Ivan
- [Local constants in Svelte with the @const tag](https://geoffrich.net/posts/local-constants/) by Geoff Rich
- [Design Patterns for Building Reusable Svelte Components](https://render.com/blog/svelte-design-patterns) by Eric Liu
- [Svelte is better than React](https://labs.hamy.xyz/posts/svelte-is-better-than-react/) by Hamilton Greene
- [Making Visualizations Literally with Svelte and D3](https://www.connorrothschild.com/post/svelte-and-d3) by Connor Rothschild
- [Coordinating Multiple Elements with Svelte Deferred Transitions](https://imfeld.dev/writing/svelte_deferred_transitions) by Daniel Imfeld
- [Animate on scroll with Svelte Inview - Little Bits](https://dev.to/maciekgrzybek/animate-on-scroll-with-svelte-inview-266f) by Maciek Grzybek
- [Lazy-Loading Firebase with SvelteKit](https://www.captaincodeman.com/lazy-loading-firebase-with-sveltekit) and [HeadlessUI Components with Svelte](https://www.captaincodeman.com/headlessui-components-with-svelte) by Captain Codeman
- [SvelteKit Accessibility Testing: Automated CI A11y Tests](https://rodneylab.com/sveltekit-accessibility-testing/) by Rodney Lab
- [Getting Started with KitQL and GraphCMS](https://scottspence.com/posts/getting-started-with-kitql-and-graphcms) by Scott Spence
- [React ⇆ Svelte Cheatsheet](https://dev.to/joshnuss/react-to-svelte-cheatsheet-1a2a) lists the similarities and differences between the two libraries - by Joshua Nussbaum
_To Watch_
- [Svelte Extravaganza | Async](https://www.youtube.com/watch?v=mT4CLVHgtSg) by pngwn
- [6 Svelte Packages You Should Know](https://www.youtube.com/watch?v=y5SrUKcX_Co) and [Basic React To Svelte Conversion](https://www.youtube.com/watch?v=DiSuwLlhOxs) by LevelUpTuts
- [Page/Shadow Endpoint in SvelteKit](https://www.youtube.com/watch?v=j-9D5UDyVOM) by WebJeda
- [Custom Svelte Store: Higher Order Store](https://www.youtube.com/watch?v=p1aPfVyZ1IY) by lihautan
- [SvelteKit For Beginners (Playlist)](https://www.youtube.com/watch?v=bLBHecY4-ak&list=PLA9WiRZ-IS_zXZZyW4qfj0akvOAtk6MFS) by Joy of Code - follow along with the [blog guide](https://joyofcode.xyz/sveltekit-for-beginners)
- [Fullstack SvelteKit Auth 🔐 with Firebase & Magic Links! 🪄](https://www.youtube.com/watch?v=MAHE4iQgh5Q) by Johnny Magrippis
- [Firebase Authentication in SvelteKit! Full Stack App](https://www.youtube.com/watch?v=N6Y3hqhZvNI) by Ryan Boddy
**Libraries, Tools & Components**
- [SvelTable](https://sveltable.io/) is a feature rich, data table component built with Svelte
- [svelte-cyberComp](https://github.com/Cybersteam00/svelte-cyberComp) is a powerful, lightweight component library written in Svelte and Typescript
- [Flowbite Svelte](https://github.com/shinokada/flowbite-svelte) is an unofficial Flowbite component library for Svelte
- [Svelte-Tide-Project](https://github.com/jbertovic/svelte-tide-project) is a starter template for Svelte frontend apps with Rust Tide backend server
- [Fetch Inject](https://github.com/vhscom/fetch-inject#sveltekit) implements a performance optimization technique for managing asynchronous JavaScript dependencies - now with Svelte support
- [svelte-utterances](https://github.com/shinokada/svelte-utterances) is a lightweight comments widget built on GitHub issues
- [Liquivelte](https://github.com/malipetek/liquivelte-vscode) allows you to create your Shopify theme with Svelte-like components
- [@storyblok/svelte](https://github.com/storyblok/storyblok-svelte) is the Svelte SDK you need to interact with Storyblok API and enable the Real-time Visual Editing Experience
- [@svelte-on-solana/wallet-adapter](https://github.com/svelte-on-solana/wallet-adapter) is a modular TypeScript wallet adapter and UI components for Solana/Anchor applications using SvelteJS as framework
- [svelte-lookat](https://www.npmjs.com/package/svelte-lookat) creates a div which makes all its children follow the mouse cursor or the user's face when using a mobile phone
Join us on [Reddit](https://www.reddit.com/r/sveltejs/) or [Discord](https://discord.com/invite/yy75DKs) to continue the conversation.
See y'all next month!

@ -0,0 +1,23 @@
---
title: Getting started
---
---
To try Svelte in an interactive online environment you can try [the REPL](https://svelte.dev/repl) or [StackBlitz](https://node.new/svelte).
To create a project locally we recommend using [SvelteKit](https://kit.svelte.dev/), the official application framework from the Svelte team:
```
npm create svelte@latest myapp
cd myapp
npm install
npm run dev
```
SvelteKit will handle calling [the Svelte compiler](https://www.npmjs.com/package/svelte) to convert your `.svelte` files into `.js` files that create the DOM and `.css` files that style it. It also provides all the other pieces you need to build a web application such as a development server, routing, and deployment. [SvelteKit](https://kit.svelte.dev/) utilizes [Vite](https://vitejs.dev/) to build your code and handle server-side rendering (SSR). There are [plugins for all the major web bundlers](https://sveltesociety.dev/tools#bundling) to handle Svelte compilation, which will output `.js` and `.css` that you can insert into your HTML, but most others won't handle SSR.
If you don't need a full-fledged app framework and instead want to build a simple frontend-only site/app, you can also use Svelte (without Kit) with Vite by running `npm init vite` and selecting the `svelte` option. With this, `npm run build` will generate HTML, JS and CSS files inside the `dist` directory.
The Svelte team maintains a [VS Code extension](https://marketplace.visualstudio.com/items?itemName=svelte.svelte-vscode) and there are integrations with various other [editors](https://sveltesociety.dev/tools#editor-support) and tools as well.
If you're having trouble, get help on [Discord](https://svelte.dev/chat) or [StackOverflow](https://stackoverflow.com/questions/tagged/svelte).

@ -55,9 +55,7 @@ In development mode (see the [compiler options](/docs#compile-time-svelte-compil
--- ---
If you export a `const`, `class` or `function`, it is readonly from outside the component. Function *expressions* are valid props, however. If you export a `const`, `class` or `function`, it is readonly from outside the component. Functions are valid prop values, however, as shown below.
Readonly props can be accessed as properties on the element, tied to the component using [`bind:this` syntax](/docs#template-syntax-component-directives-bind-this).
```sv ```sv
<script> <script>
@ -73,6 +71,8 @@ Readonly props can be accessed as properties on the element, tied to the compone
</script> </script>
``` ```
Readonly props can be accessed as properties on the element, tied to the component using [`bind:this` syntax](/docs#template-syntax-component-directives-bind-this).
--- ---
You can use reserved words as prop names. You can use reserved words as prop names.
@ -125,15 +125,29 @@ Because Svelte's reactivity is based on assignments, using array methods like `.
</script> </script>
``` ```
---
Svelte's `<script>` blocks are run only when the component is created, so assignments within a `<script>` block are not automatically run again when a prop updates. If you'd like to track changes to a prop, see the next example in the following section.
```sv
<script>
export let person;
// this will only set `name` on component creation
// it will not update when `person` does
let { name } = person;
</script>
```
#### 3. `$:` marks a statement as reactive #### 3. `$:` marks a statement as reactive
--- ---
Any top-level statement (i.e. not inside a block or a function) can be made reactive by prefixing it with the `$:` [JS label syntax](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/label). Reactive statements run immediately before the component updates, whenever the values that they depend on have changed. Any top-level statement (i.e. not inside a block or a function) can be made reactive by prefixing it with the `$:` [JS label syntax](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/label). Reactive statements run after other script code and before the component markup is rendered, whenever the values that they depend on have changed.
```sv ```sv
<script> <script>
export let title; export let title;
export let person;
// this will update `document.title` whenever // this will update `document.title` whenever
// the `title` prop changes // the `title` prop changes
@ -143,6 +157,12 @@ Any top-level statement (i.e. not inside a block or a function) can be made reac
console.log(`multiple statements can be combined`); console.log(`multiple statements can be combined`);
console.log(`the current title is ${title}`); console.log(`the current title is ${title}`);
} }
// this will update `name` when 'person' changes
$: ({ name } = person);
// don't do this. it will run before the previous line
let name2 = name;
</script> </script>
``` ```
@ -172,6 +192,25 @@ Total: {total}
</button> </button>
``` ```
---
It is important to note that the reactive blocks are ordered via simple static analysis at compile time, and all the compiler looks at are the variables that are assigned to and used within the block itself, not in any functions called by them. This means that `yDependent` will not be updated when `x` is updated in the following example:
```sv
<script>
let x = 0;
let y = 0;
const setY = (value) => {
y = value;
}
$: yDependent = y;
$: setY(x);
</script>
```
Moving the line `$: yDependent = y` below `$: setY(x)` will cause `yDependent` to be updated when `x` is updated.
--- ---
If a statement consists entirely of an assignment to an undeclared variable, Svelte will inject a `let` declaration on your behalf. If a statement consists entirely of an assignment to an undeclared variable, Svelte will inject a `let` declaration on your behalf.

@ -124,6 +124,10 @@ An element or component can have multiple spread attributes, interspersed with r
> The `value` attribute of an `input` element or its children `option` elements must not be set with spread attributes when using `bind:group` or `bind:checked`. Svelte needs to be able to see the element's `value` directly in the markup in these cases so that it can link it to the bound variable. > The `value` attribute of an `input` element or its children `option` elements must not be set with spread attributes when using `bind:group` or `bind:checked`. Svelte needs to be able to see the element's `value` directly in the markup in these cases so that it can link it to the bound variable.
> Sometimes, the attribute order matters as Svelte sets attributes sequentially in JavaScript. For example, `<input type="range" min="0" max="1" value={0.5} step="0.1"/>`, Svelte will attempt to set the value to `1` (rounding up from 0.5 as the step by default is 1), and then set the step to `0.1`. To fix this, change it to `<input type="range" min="0" max="1" step="0.1" value={0.5}/>`.
> Another example is `<img src="..." loading="lazy" />`. Svelte will set the img `src` before making the img element `loading="lazy"`, which is probably too late. Change this to `<img loading="lazy" src="...">` to make the image lazily loaded.
--- ---
### Text expressions ### Text expressions
@ -158,7 +162,7 @@ You can use HTML comments inside components.
--- ---
Comments beginning with `svelte-ignore` disable warnings for the next block of markup. Usually these are accessibility warnings; make sure that you're disabling them for a good reason. Comments beginning with `svelte-ignore` disable warnings for the next block of markup. Usually, these are accessibility warnings; make sure that you're disabling them for a good reason.
```sv ```sv
<!-- svelte-ignore a11y-autofocus --> <!-- svelte-ignore a11y-autofocus -->
@ -202,6 +206,7 @@ Additional conditions can be added with `{:else if expression}`, optionally endi
{/if} {/if}
``` ```
(Blocks don't have to wrap elements, they can also wrap text within elements!)
### {#each ...} ### {#each ...}
@ -465,16 +470,16 @@ The `{@const ...}` tag defines a local constant.
```sv ```sv
<script> <script>
export let boxes; export let boxes;
</script> </script>
{#each boxes as box} {#each boxes as box}
{@const area = box.width * box.height} {@const area = box.width * box.height}
{box.width} * {box.height} = {area} {box.width} * {box.height} = {area}
{/each} {/each}
``` ```
`{@const}` is only allowed as direct child of `{#each}`, `{:then}`, `{:catch}`, `<Component />` or `<svelte:fragment />`. `{@const}` is only allowed as direct child of `{#if}`, `{:else if}`, `{:else}`, `{#each}`, `{:then}`, `{:catch}`, `<Component />` or `<svelte:fragment />`.
### Element directives ### Element directives
@ -593,7 +598,7 @@ The simplest bindings reflect the value of a property, such as `input.value`.
--- ---
If the name matches the value, you can use a shorthand. If the name matches the value, you can use shorthand.
```sv ```sv
<!-- These are equivalent --> <!-- These are equivalent -->
@ -627,7 +632,7 @@ On `<input>` elements with `type="file"`, you can use `bind:files` to get the [`
--- ---
`bind:` can be used together with `on:` directives. The order that they are defined in determines the value of the bound variable when the event handler is called. If you're using `bind:` directives together with `on:` directives, the order that they're defined in affects the value of the bound variable when the event handler is called.
```sv ```sv
<script> <script>
@ -641,6 +646,7 @@ On `<input>` elements with `type="file"`, you can use `bind:files` to get the [`
/> />
``` ```
Here we were binding to the value of a text input, which uses the `input` event. Bindings on other elements may use different events such as `change`.
##### Binding `<select>` value ##### Binding `<select>` value
@ -658,7 +664,7 @@ A `<select>` value binding corresponds to the `value` property on the selected `
--- ---
A `<select multiple>` element behaves similarly to a checkbox group. A `<select multiple>` element behaves similarly to a checkbox group. The bound variable is an array with an entry corresponding to the `value` property of each selected `<option>`.
```sv ```sv
<select multiple bind:value={fillings}> <select multiple bind:value={fillings}>
@ -745,11 +751,27 @@ Videos additionally have readonly `videoWidth` and `videoHeight` bindings.
></video> ></video>
``` ```
##### Image element bindings
---
Image elements (`<img>`) have two readonly bindings:
* `naturalWidth` (readonly) — the original width of the image, available after the image has loaded
* `naturalHeight` (readonly) — the original height of the image, available after the image has loaded
```sv
<img
bind:naturalWidth
bind:naturalHeight
></img>
```
##### Block-level element bindings ##### Block-level element bindings
--- ---
Block-level elements have 4 readonly bindings, measured using a technique similar to [this one](http://www.backalleycoder.com/2013/03/18/cross-browser-event-based-element-resize-detection/): Block-level elements have 4 read-only bindings, measured using a technique similar to [this one](http://www.backalleycoder.com/2013/03/18/cross-browser-event-based-element-resize-detection/):
* `clientWidth` * `clientWidth`
* `clientHeight` * `clientHeight`
@ -873,6 +895,9 @@ The `style:` directive provides a shorthand for setting multiple styles on an el
<!-- Multiple styles can be included --> <!-- Multiple styles can be included -->
<div style:color style:width="12rem" style:background-color={darkMode ? "black" : "white"}>...</div> <div style:color style:width="12rem" style:background-color={darkMode ? "black" : "white"}>...</div>
<!-- Styles can be marked as important -->
<div style:color|important="red">...</div>
``` ```
--- ---
@ -967,7 +992,7 @@ transition:fn|local={params}
```js ```js
transition = (node: HTMLElement, params: any) => { transition = (node: HTMLElement, params: any, options: { direction: 'in' | 'out' | 'both' }) => {
delay?: number, delay?: number,
duration?: number, duration?: number,
easing?: (t: number) => number, easing?: (t: number) => number,
@ -980,7 +1005,7 @@ transition = (node: HTMLElement, params: any) => {
A transition is triggered by an element entering or leaving the DOM as a result of a state change. A transition is triggered by an element entering or leaving the DOM as a result of a state change.
When a block is transitioning out, all elements inside the block, including those that do not have their own transitions, are kept in the DOM until every transition in the block has completed. When a block is transitioning out, all elements inside the block, including those that do not have their own transitions, are kept in the DOM until every transition in the block has been completed.
The `transition:` directive indicates a *bidirectional* transition, which means it can be smoothly reversed while the transition is in progress. The `transition:` directive indicates a *bidirectional* transition, which means it can be smoothly reversed while the transition is in progress.
@ -1005,7 +1030,7 @@ Like actions, transitions can have parameters.
```sv ```sv
{#if visible} {#if visible}
<div transition:fade="{{ duration: 2000 }}"> <div transition:fade="{{ duration: 2000 }}">
flies in, fades out over two seconds fades in and out over two seconds
</div> </div>
{/if} {/if}
``` ```
@ -1016,7 +1041,7 @@ Like actions, transitions can have parameters.
Transitions can use custom functions. If the returned object has a `css` function, Svelte will create a CSS animation that plays on the element. Transitions can use custom functions. If the returned object has a `css` function, Svelte will create a CSS animation that plays on the element.
The `t` argument passed to `css` is a value between `0` and `1` after the `easing` function has been applied. *In* transitions run from `0` to `1`, *out* transitions run from `1` to `0` in other words `1` is the element's natural state, as though no transition had been applied. The `u` argument is equal to `1 - t`. The `t` argument passed to `css` is a value between `0` and `1` after the `easing` function has been applied. *In* transitions run from `0` to `1`, *out* transitions run from `1` to `0` in other words, `1` is the element's natural state, as though no transition had been applied. The `u` argument is equal to `1 - t`.
The function is called repeatedly *before* the transition begins, with different `t` and `u` arguments. The function is called repeatedly *before* the transition begins, with different `t` and `u` arguments.
@ -1087,6 +1112,11 @@ A custom transition function can also return a `tick` function, which is called
If a transition returns a function instead of a transition object, the function will be called in the next microtask. This allows multiple transitions to coordinate, making [crossfade effects](/tutorial/deferred-transitions) possible. If a transition returns a function instead of a transition object, the function will be called in the next microtask. This allows multiple transitions to coordinate, making [crossfade effects](/tutorial/deferred-transitions) possible.
Transition functions also receive a third argument, `options`, which contains information about the transition.
Available values in the `options` object are:
* `direction` - one of `in`, `out`, or `both` depending on the type of transition
##### Transition events ##### Transition events
@ -1240,7 +1270,7 @@ As with actions and transitions, animations can have parameters.
--- ---
Animations can use custom functions that provide the `node`, an `animation` object and any `parameters` as arguments. The `animation` parameter is an object containing `from` and `to` properties each containing a [DOMRect](https://developer.mozilla.org/en-US/docs/Web/API/DOMRect#Properties) describing the geometry of the element in its `start` and `end` positions. The `from` property is the DOMRect of the element in its starting position, the `to` property is the DOMRect of the element in its final position after the list has been reordered and the DOM updated. Animations can use custom functions that provide the `node`, an `animation` object and any `parameters` as arguments. The `animation` parameter is an object containing `from` and `to` properties each containing a [DOMRect](https://developer.mozilla.org/en-US/docs/Web/API/DOMRect#Properties) describing the geometry of the element in its `start` and `end` positions. The `from` property is the DOMRect of the element in its starting position, and the `to` property is the DOMRect of the element in its final position after the list has been reordered and the DOM updated.
If the returned object has a `css` method, Svelte will create a CSS animation that plays on the element. If the returned object has a `css` method, Svelte will create a CSS animation that plays on the element.
@ -1294,14 +1324,12 @@ A custom animation function can also return a `tick` function, which is called *
const d = Math.sqrt(dx * dx + dy * dy); const d = Math.sqrt(dx * dx + dy * dy);
return { return {
delay: 0, delay: 0,
duration: Math.sqrt(d) * 120, duration: Math.sqrt(d) * 120,
easing: cubicOut, easing: cubicOut,
tick: (t, u) => tick: (t, u) =>
Object.assign(node.style, { Object.assign(node.style, { color: t > 0.5 ? 'Pink' : 'Blue' })
color: t > 0.5 ? 'Pink' : 'Blue' };
});
};
} }
</script> </script>
@ -1373,7 +1401,23 @@ Desugars to this:
--- ---
Svelte's CSS Variables support allows for easily themable components: For SVG namespace, the example above desugars into using `<g>` instead:
```sv
<g style="--rail-color: black; --track-color: rgb(0, 0, 255)">
<Slider
bind:value
min={0}
max={100}
/>
</g>
```
**Note**: Since this is an extra `<g>`, beware that your CSS structure might accidentally target this. Be mindful of this added wrapper element when using this feature.
---
Svelte's CSS Variables support allows for easily themeable components:
```sv ```sv
<!-- Slider.svelte --> <!-- Slider.svelte -->
@ -1386,7 +1430,7 @@ Svelte's CSS Variables support allows for easily themable components:
--- ---
So you can set a high level theme color: So you can set a high-level theme color:
```css ```css
/* global.css */ /* global.css */
@ -1473,6 +1517,8 @@ The content is exposed in the child component using the `<slot>` element, which
</Widget> </Widget>
``` ```
Note: If you want to render regular `<slot>` element, You can use `<svelte:element this="slot" />`.
#### `<slot name="`*name*`">` #### `<slot name="`*name*`">`
--- ---
@ -1546,7 +1592,7 @@ Note that explicitly passing in an empty named slot will add that slot's name to
--- ---
Slots can be rendered zero or more times, and can pass values *back* to the parent using props. The parent exposes the values to the slot template using the `let:` directive. Slots can be rendered zero or more times and can pass values *back* to the parent using props. The parent exposes the values to the slot template using the `let:` directive.
The usual shorthand rules apply — `let:item` is equivalent to `let:item={item}`, and `<slot {item}>` is equivalent to `<slot item={item}>`. The usual shorthand rules apply — `let:item` is equivalent to `let:item={item}`, and `<slot {item}>` is equivalent to `<slot item={item}>`.
@ -1635,11 +1681,13 @@ If `this` is falsy, no component is rendered.
--- ---
The `<svelte:element>` element lets you render an element of a dynamically specified type. This is useful for example when rich text content from a CMS. If the tag is changed, the children will be preserved unless there's a transition attached to the element. Any properties and event listeners present will be applied to the element. The `<svelte:element>` element lets you render an element of a dynamically specified type. This is useful for example when displaying rich text content from a CMS. Any properties and event listeners present will be applied to the element.
The only supported binding is `bind:this`, since the element type-specific bindings that Svelte does at build time (e.g. `bind:value` for input elements) do not work with a dynamic tag type.
The only supported binding is `bind:this`, since the element type specific bindings that Svelte does at build time (e.g. `bind:value` for input elements) does not work with a dynamic tag type. If `this` has a nullish value, the element and its children will not be rendered.
If `this` has a nullish value, a warning will be logged in development mode. If `this` is the name of a [void element](https://developer.mozilla.org/en-US/docs/Glossary/Void_element) (e.g., `br`) and `<svelte:element>` has child elements, a runtime error will be thrown in development mode.
```sv ```sv
<script> <script>
@ -1663,7 +1711,7 @@ If `this` has a nullish value, a warning will be logged in development mode.
The `<svelte:window>` element allows you to add event listeners to the `window` object without worrying about removing them when the component is destroyed, or checking for the existence of `window` when server-side rendering. The `<svelte:window>` element allows you to add event listeners to the `window` object without worrying about removing them when the component is destroyed, or checking for the existence of `window` when server-side rendering.
Unlike `<svelte:self>`, this element may only appear the top level of your component and must never be inside a block or element. Unlike `<svelte:self>`, this element may only appear at the top level of your component and must never be inside a block or element.
```sv ```sv
<script> <script>
@ -1685,7 +1733,7 @@ You can also bind to the following properties:
* `outerHeight` * `outerHeight`
* `scrollX` * `scrollX`
* `scrollY` * `scrollY`
* `online` — an alias for window.navigator.onLine * `online` — an alias for `window.navigator.onLine`
All except `scrollX` and `scrollY` are readonly. All except `scrollX` and `scrollY` are readonly.

@ -452,6 +452,29 @@ import { get } from 'svelte/store';
const value = get(store); const value = get(store);
``` ```
#### `readonly`
```js
readableStore = readonly(writableStore);
```
---
This simple helper function makes a store readonly. You can still subscribe to the changes from the original one using this new readable store.
```js
import { readonly } from 'svelte/store';
const writableStore = writable(1);
const readableStore = readonly(writableStore);
readableStore.subscribe(console.log);
writableStore.set(2); // console: 2
readableStore.set(2); // ERROR
```
### `svelte/motion` ### `svelte/motion`
@ -558,10 +581,34 @@ A `spring` store gradually changes to its target value based on its `stiffness`
--- ---
As with [`tweened`](/docs#run-time-svelte-motion-tweened) stores, `set` and `update` return a Promise that resolves if the spring settles. The `store.stiffness` and `store.damping` properties can be changed while the spring is in motion, and will take immediate effect. All of the options above can be changed while the spring is in motion, and will take immediate effect.
```js
const size = spring(100);
size.stiffness = 0.3;
size.damping = 0.4;
size.precision = 0.005;
```
---
As with [`tweened`](/docs#run-time-svelte-motion-tweened) stores, `set` and `update` return a Promise that resolves if the spring settles.
Both `set` and `update` can take a second argument — an object with `hard` or `soft` properties. `{ hard: true }` sets the target value immediately; `{ soft: n }` preserves existing momentum for `n` seconds before settling. `{ soft: true }` is equivalent to `{ soft: 0.5 }`. Both `set` and `update` can take a second argument — an object with `hard` or `soft` properties. `{ hard: true }` sets the target value immediately; `{ soft: n }` preserves existing momentum for `n` seconds before settling. `{ soft: true }` is equivalent to `{ soft: 0.5 }`.
```js
const coords = spring({ x: 50, y: 50 });
// updates the value immediately
coords.set({ x: 100, y: 200 }, { hard: true });
// preserves existing momentum for 1s
coords.update(
(target_coords, coords) => {
return { x: target_coords.x, y: coords.y };
},
{ soft: 1 }
);
```
[See a full example on the spring tutorial.](/tutorial/spring) [See a full example on the spring tutorial.](/tutorial/spring)
```sv ```sv
@ -674,7 +721,7 @@ out:fly={params}
--- ---
Animates the x and y positions and the opacity of an element. `in` transitions animate from an element's current (default) values to the provided values, passed as parameters. `out` transitions animate from the provided values to an element's default values. Animates the x and y positions and the opacity of an element. `in` transitions animate from the provided values, passed as parameters to the element's default values. `out` transitions animate from the element's default values to the provided values.
`fly` accepts the following parameters: `fly` accepts the following parameters:
@ -721,6 +768,7 @@ Slides an element in and out.
* `delay` (`number`, default 0) — milliseconds before starting * `delay` (`number`, default 0) — milliseconds before starting
* `duration` (`number`, default 400) — milliseconds the transition lasts * `duration` (`number`, default 400) — milliseconds the transition lasts
* `easing` (`function`, default `cubicOut`) — an [easing function](/docs#run-time-svelte-easing) * `easing` (`function`, default `cubicOut`) — an [easing function](/docs#run-time-svelte-easing)
- `axis` (`x` | `y`, default `y`) — the axis of motion along which the transition occurs
```sv ```sv
<script> <script>
@ -729,8 +777,8 @@ Slides an element in and out.
</script> </script>
{#if condition} {#if condition}
<div transition:slide="{{delay: 250, duration: 300, easing: quintOut }}"> <div transition:slide="{{delay: 250, duration: 300, easing: quintOut, axis: 'x'}}">
slides in and out slides in and out horizontally
</div> </div>
{/if} {/if}
``` ```
@ -829,7 +877,7 @@ The `crossfade` function creates a pair of [transitions](/docs#template-syntax-e
* `delay` (`number`, default 0) — milliseconds before starting * `delay` (`number`, default 0) — milliseconds before starting
* `duration` (`number` | `function`, default 800) — milliseconds the transition lasts * `duration` (`number` | `function`, default 800) — milliseconds the transition lasts
* `easing` (`function`, default `cubicOut`) — an [easing function](/docs#run-time-svelte-easing) * `easing` (`function`, default `cubicOut`) — an [easing function](/docs#run-time-svelte-easing)
* `fallback` (`function`) — A fallback [transition](/docs#template-syntax-element-directives-transition-fn) to use for send when there is no matching element being received, and for receive when there is no element being sent. * `fallback` (`function`) — A fallback [transition](/docs#template-syntax-element-directives-transition-fn) to use for send when there is no matching element being received, and for receive when there is no element being sent.
```sv ```sv
<script> <script>

@ -73,7 +73,7 @@ The following options can be passed to the compiler. None are required:
| `accessors` | `false` | If `true`, getters and setters will be created for the component's props. If `false`, they will only be created for readonly exported values (i.e. those declared with `const`, `class` and `function`). If compiling with `customElement: true` this option defaults to `true`. | `accessors` | `false` | If `true`, getters and setters will be created for the component's props. If `false`, they will only be created for readonly exported values (i.e. those declared with `const`, `class` and `function`). If compiling with `customElement: true` this option defaults to `true`.
| `customElement` | `false` | If `true`, tells the compiler to generate a custom element constructor instead of a regular Svelte component. | `customElement` | `false` | If `true`, tells the compiler to generate a custom element constructor instead of a regular Svelte component.
| `tag` | `null` | A `string` that tells Svelte what tag name to register the custom element with. It must be a lowercase alphanumeric string with at least one hyphen, e.g. `"my-element"`. | `tag` | `null` | A `string` that tells Svelte what tag name to register the custom element with. It must be a lowercase alphanumeric string with at least one hyphen, e.g. `"my-element"`.
| `css` | `true` | If `true`, styles will be included in the JavaScript class and injected at runtime for the components actually rendered. If `false`, the CSS will be returned in the `css` field of the compilation result. Most Svelte bundler plugins will set this to `false` and use the CSS that is statically generated for better performance, as it will result in smaller JavaScript bundles and the output can be served as cacheable `.css` files. | `css` | `'injected'` | If `'injected'` (formerly `true`), styles will be included in the JavaScript class and injected at runtime for the components actually rendered. If `'external'` (formerly `false`), the CSS will be returned in the `css` field of the compilation result. Most Svelte bundler plugins will set this to `'external'` and use the CSS that is statically generated for better performance, as it will result in smaller JavaScript bundles and the output can be served as cacheable `.css` files. If `'none'`, styles are completely avoided and no CSS output is generated.
| `cssHash` | See right | A function that takes a `{ hash, css, name, filename }` argument and returns the string that is used as a classname for scoped CSS. It defaults to returning `svelte-${hash(css)}` | `cssHash` | See right | A function that takes a `{ hash, css, name, filename }` argument and returns the string that is used as a classname for scoped CSS. It defaults to returning `svelte-${hash(css)}`
| `loopGuardTimeout` | 0 | A `number` that tells Svelte to break the loop if it blocks the thread for more than `loopGuardTimeout` ms. This is useful to prevent infinite loops. **Only available when `dev: true`** | `loopGuardTimeout` | 0 | A `number` that tells Svelte to break the loop if it blocks the thread for more than `loopGuardTimeout` ms. This is useful to prevent infinite loops. **Only available when `dev: true`**
| `preserveComments` | `false` | If `true`, your HTML comments will be preserved during server-side rendering. By default, they are stripped out. | `preserveComments` | `false` | If `true`, your HTML comments will be preserved during server-side rendering. By default, they are stripped out.

@ -19,6 +19,18 @@ Enforce no `accesskey` on element. Access keys are HTML attributes that allow we
--- ---
### `a11y-aria-activedescendant-has-tabindex`
An element with `aria-activedescendant` must be tabbable, so it must either have an inherent `tabindex` or declare `tabindex` as an attribute.
```sv
<!-- A11y: Elements with attribute aria-activedescendant should have tabindex value -->
<div aria-activedescendant="some-id" />
```
---
### `a11y-aria-attributes` ### `a11y-aria-attributes`
Certain reserved DOM elements do not support ARIA roles, states and properties. This is often because they are not visible, for example `meta`, `html`, `script`, `style`. This rule enforces that these DOM elements do not contain the `aria-*` props. Certain reserved DOM elements do not support ARIA roles, states and properties. This is often because they are not visible, for example `meta`, `html`, `script`, `style`. This rule enforces that these DOM elements do not contain the `aria-*` props.
@ -41,6 +53,19 @@ Enforce that `autofocus` is not used on elements. Autofocusing elements can caus
--- ---
### `a11y-click-events-have-key-events`
Enforce `on:click` is accompanied by at least one of the following: `onKeyUp`, `onKeyDown`, `onKeyPress`. Coding for the keyboard is important for users with physical disabilities who cannot use a mouse, AT compatibility, and screenreader users.
This does not apply for interactive or hidden elements.
```sv
<!-- A11y: visible, non-interactive elements with an on:click event must be accompanied by an on:keydown, on:keyup, or on:keypress event. -->
<div on:click={() => {}} />
```
---
### `a11y-distracting-elements` ### `a11y-distracting-elements`
Enforces that no distracting elements are used. Elements that can be visually distracting can cause accessibility issues with visually impaired users. Such elements are most likely deprecated, and should be avoided. Enforces that no distracting elements are used. Elements that can be visually distracting can cause accessibility issues with visually impaired users. Such elements are most likely deprecated, and should be avoided.
@ -87,6 +112,18 @@ Enforce img alt attribute does not contain the word image, picture, or photo. Sc
--- ---
### `a11y-incorrect-aria-attribute-type`
Enforce that only the correct type of value is used for aria attributes. For example, `aria-hidden`
should only receive a boolean.
```sv
<!-- A11y: The value of 'aria-hidden' must be exactly one of true or false -->
<div aria-hidden="yes"/>
```
---
### `a11y-invalid-attribute` ### `a11y-invalid-attribute`
Enforce that attributes important for accessibility have a valid value. For example, `href` should not be empty, `'#'`, or `javascript:`. Enforce that attributes important for accessibility have a valid value. For example, `href` should not be empty, `'#'`, or `javascript:`.
@ -227,6 +264,28 @@ Some HTML elements have default ARIA roles. Giving these elements an ARIA role t
--- ---
### `a11y-no-interactive-element-to-noninteractive-role`
[WAI-ARIA](https://www.w3.org/TR/wai-aria-1.1/#usage_intro) roles should not be used to convert an interactive element to a non-interactive element. Non-interactive ARIA roles include `article`, `banner`, `complementary`, `img`, `listitem`, `main`, `region` and `tooltip`.
```sv
<!-- A11y: <textarea> cannot have role 'listitem' -->
<textarea role="listitem" />
```
---
### `a11y-no-noninteractive-tabindex`
Tab key navigation should be limited to elements on the page that can be interacted with.
```sv
<!-- A11y: noninteractive element cannot have nonnegative tabIndex value -->
<div tabindex='0' />
```
---
### `a11y-positive-tabindex` ### `a11y-positive-tabindex`
Avoid positive `tabindex` property values. This will move elements out of the expected tab order, creating a confusing experience for keyboard users. Avoid positive `tabindex` property values. This will move elements out of the expected tab order, creating a confusing experience for keyboard users.
@ -238,6 +297,31 @@ Avoid positive `tabindex` property values. This will move elements out of the ex
--- ---
### `a11y-role-has-required-aria-props`
Elements with ARIA roles must have all required attributes for that role.
```sv
<!-- A11y: A11y: Elements with the ARIA role "checkbox" must have the following attributes defined: "aria-checked" -->
<span role="checkbox" aria-labelledby="foo" tabindex="0"></span>
```
---
### `a11y-role-supports-aria-props`
Elements with explicit or implicit roles defined contain only `aria-*` properties supported by that role.
```sv
<!-- A11y: The attribute 'aria-multiline' is not supported by the role 'link'. -->
<div role="link" aria-multiline />
<!-- A11y: The attribute 'aria-required' is not supported by the role 'listitem'. This role is implicit on the element <li>. -->
<li aria-required />
```
---
### `a11y-structure` ### `a11y-structure`
Enforce that certain DOM elements have the correct structure. Enforce that certain DOM elements have the correct structure.

@ -11,7 +11,7 @@
<ul> <ul>
{#each cats as { id, name }, i} {#each cats as { id, name }, i}
<li> <li>
<a target="_blank" href="https://www.youtube.com/watch?v={id}"> <a target="_blank" rel="noreferrer" href="https://www.youtube.com/watch?v={id}">
{i + 1}: {name} {i + 1}: {name}
</a> </a>
</li> </li>

@ -10,7 +10,7 @@
{#if yes} {#if yes}
<p>Thank you. We will bombard your inbox and sell your personal details.</p> <p>Thank you. We will bombard your inbox and sell your personal details.</p>
{:else} {:else}
<p>You must opt in to continue. If you're not paying, you're the product.</p> <p>You must opt-in to continue. If you're not paying, you're the product.</p>
{/if} {/if}
<button disabled={!yes}> <button disabled={!yes}>

@ -4,7 +4,7 @@
let photos = []; let photos = [];
onMount(async () => { onMount(async () => {
const res = await fetch(`https://jsonplaceholder.typicode.com/photos?_limit=20`); const res = await fetch(`/tutorial/api/album`);
photos = await res.json(); photos = await res.json();
}); });
</script> </script>

@ -56,8 +56,8 @@
> >
<p class='credit'> <p class='credit'>
<a target="_blank" href="https://www.flickr.com/photos/{d.path}">via Flickr</a> &ndash; <a target="_blank" rel="noreferrer" href="https://www.flickr.com/photos/{d.path}">via Flickr</a> &ndash;
<a target="_blank" href={d.license.url}>{d.license.name}</a> <a target="_blank" rel="noreferrer" href={d.license.url}>{d.license.name}</a>
</p> </p>
</div> </div>
{/await} {/await}

@ -43,4 +43,8 @@
background-color: #ff3e00; background-color: #ff3e00;
color: white; color: white;
} }
</style>
p {
pointer-events: none;
}
</style>

@ -4,26 +4,26 @@
let showModal = false; let showModal = false;
</script> </script>
<button on:click="{() => showModal = true}"> <button on:click={() => (showModal = true)}>
show modal show modal
</button> </button>
{#if showModal} <Modal bind:showModal>
<Modal on:close="{() => showModal = false}"> <h2 slot="header">
<h2 slot="header"> modal
modal <small><em>adjective</em> mod·al \ˈmō-dəl\</small>
<small><em>adjective</em> mod·al \ˈmō-dəl\</small> </h2>
</h2>
<ol class="definition-list"> <ol class="definition-list">
<li>of or relating to modality in logic</li> <li>of or relating to modality in logic</li>
<li>containing provisions as to the mode of procedure or the manner of taking effect —used of a contract or legacy</li> <li>
<li>of or relating to a musical mode</li> containing provisions as to the mode of procedure or the manner of taking effect —used of a contract or legacy
<li>of or relating to structure as opposed to substance</li> </li>
<li>of, relating to, or constituting a grammatical form or category characteristically indicating predication</li> <li>of or relating to a musical mode</li>
<li>of or relating to a statistical mode</li> <li>of or relating to structure as opposed to substance</li>
</ol> <li>of, relating to, or constituting a grammatical form or category characteristically indicating predication</li>
<li>of or relating to a statistical mode</li>
</ol>
<a href="https://www.merriam-webster.com/dictionary/modal">merriam-webster.com</a> <a href="https://www.merriam-webster.com/dictionary/modal">merriam-webster.com</a>
</Modal> </Modal>
{/if}

@ -1,81 +1,63 @@
<script> <script>
import { createEventDispatcher, onDestroy } from 'svelte'; export let showModal; // boolean
const dispatch = createEventDispatcher(); let dialog; // HTMLDialogElement
const close = () => dispatch('close');
let modal; $: if (dialog && showModal) dialog.showModal();
const handle_keydown = e => {
if (e.key === 'Escape') {
close();
return;
}
if (e.key === 'Tab') {
// trap focus
const nodes = modal.querySelectorAll('*');
const tabbable = Array.from(nodes).filter(n => n.tabIndex >= 0);
let index = tabbable.indexOf(document.activeElement);
if (index === -1 && e.shiftKey) index = 0;
index += tabbable.length + (e.shiftKey ? -1 : 1);
index %= tabbable.length;
tabbable[index].focus();
e.preventDefault();
}
};
const previously_focused = typeof document !== 'undefined' && document.activeElement;
if (previously_focused) {
onDestroy(() => {
previously_focused.focus();
});
}
</script> </script>
<svelte:window on:keydown={handle_keydown}/> <!-- svelte-ignore a11y-click-events-have-key-events -->
<dialog
<div class="modal-background" on:click={close}></div> bind:this={dialog}
on:close={() => (showModal = false)}
<div class="modal" role="dialog" aria-modal="true" bind:this={modal}> on:click|self={() => dialog.close()}
<slot name="header"></slot> >
<hr> <div on:click|stopPropagation>
<slot></slot> <slot name="header" />
<hr> <hr />
<slot />
<!-- svelte-ignore a11y-autofocus --> <hr />
<button autofocus on:click={close}>close modal</button> <!-- svelte-ignore a11y-autofocus -->
</div> <button autofocus on:click={() => dialog.close()}>close modal</button>
</div>
</dialog>
<style> <style>
.modal-background { dialog {
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100%;
background: rgba(0,0,0,0.3);
}
.modal {
position: absolute;
left: 50%;
top: 50%;
width: calc(100vw - 4em);
max-width: 32em; max-width: 32em;
max-height: calc(100vh - 4em);
overflow: auto;
transform: translate(-50%,-50%);
padding: 1em;
border-radius: 0.2em; border-radius: 0.2em;
background: white; border: none;
padding: 0;
}
dialog::backdrop {
background: rgba(0, 0, 0, 0.3);
}
dialog > div {
padding: 1em;
}
dialog[open] {
animation: zoom 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}
@keyframes zoom {
from {
transform: scale(0.95);
}
to {
transform: scale(1);
}
}
dialog[open]::backdrop {
animation: fade 0.2s ease-out;
}
@keyframes fade {
from {
opacity: 0;
}
to {
opacity: 1;
}
} }
button { button {
display: block; display: block;
} }
</style> </style>

@ -13,7 +13,7 @@
<article> <article>
<span>{i + offset + 1}</span> <span>{i + offset + 1}</span>
<h2><a target="_blank" href={url}>{item.title}</a></h2> <h2><a target="_blank" rel="noreferrer" href={url}>{item.title}</a></h2>
<p class="meta"><a href="#/item/{item.id}">{comment_text()}</a> by {item.user} {item.time_ago}</p> <p class="meta"><a href="#/item/{item.id}">{comment_text()}</a> by {item.user} {item.time_ago}</p>
</article> </article>
@ -37,4 +37,4 @@
a { a {
color: #333; color: #333;
} }
</style> </style>

@ -1,5 +0,0 @@
---
question: How can I update my components written in Svelte v2?
---
svelte-upgrade isn't fully working for v2->v3 yet, [but it's close](https://github.com/sveltejs/svelte-upgrade/pull/12).

@ -2,11 +2,20 @@
question: How do I test Svelte apps? question: How do I test Svelte apps?
--- ---
We recommend trying to separate your view logic from your business logic. Data transformation or cross component state management is best kept outside of Svelte components. You can test those parts like you would test any JavaScript functionality that way. When it comes to testing the components, it is best to test the logic of the component and remember that the Svelte library has its own tests and you do not need to test implementation details provided by Svelte. How your application is structured and where logic is defined will determine the best way to ensure it is properly tested. It is important to note that not all logic belongs within a component - this includes concerns such as data transformation, cross-component state management, and logging, among others. Remember that the Svelte library has its own test suite, so you do not need to write tests to validate implementation details provided by Svelte.
There are a few approaches that people take when testing, but it generally involves compiling the component and mounting it to something and then performing the tests. You essentially need to create a bundle for each component you're testing (since svelte is a compiler and not a normal library) and then mount them. You can mount to a JSDOM instance. Or you can use a real browser powered by a library like Playwright, Puppeteer, or Cypress. A Svelte application will typically have three different types of tests: Unit, Component, and End-to-End (E2E).
Some resources for getting started with unit testing: *Unit Tests*: Focus on testing business logic in isolation. Often this is validating individual functions and edge cases. By minimizing the surface area of these tests they can be kept lean and fast, and by extracting as much logic as possible from your Svelte components more of your application can be covered using them. When creating a new SvelteKit project, you will be asked whether you would like to setup [Vitest](https://vitest.dev/) for unit testing. There are a number of other test runners that could be used as well.
*Component Tests*: Validating that a Svelte component mounts and interacts as expected throughout its lifecycle requires a tool that provides a Document Object Model (DOM). Components can be compiled (since Svelte is a compiler and not a normal library) and mounted to allow asserting against element structure, listeners, state, and all the other capabilities provided by a Svelte component. Tools for component testing range from an in-memory implementation like jsdom paired with a test runner like [Vitest](https://vitest.dev/) to solutions that leverage an actual browser to provide a visual testing capability such as [Playwright](https://playwright.dev/docs/test-components) or [Cypress](https://www.cypress.io/).
*End-to-End Tests*: To ensure your users are able to interact with your application it is necessary to test it as a whole in a manner as close to production as possible. This is done by writing end-to-end (E2E) tests which load and interact with a deployed version of your application in order to simulate how the user will interact with your application. When creating a new SvelteKit project, you will be asked whether you would like to setup [Playwright](https://playwright.dev/) for end-to-end testing. There are many other E2E test libraries available for use as well.
Some resources for getting started with testing:
- [Svelte Testing Library](https://testing-library.com/docs/svelte-testing-library/example/) - [Svelte Testing Library](https://testing-library.com/docs/svelte-testing-library/example/)
- [Svelte Component Testing in Cypress](https://docs.cypress.io/guides/component-testing/svelte/overview)
- [Example using vitest](https://github.com/vitest-dev/vitest/tree/main/examples/svelte) - [Example using vitest](https://github.com/vitest-dev/vitest/tree/main/examples/svelte)
- [Example using uvu test runner with JSDOM](https://github.com/lukeed/uvu/tree/master/examples/svelte) - [Example using uvu test runner with JSDOM](https://github.com/lukeed/uvu/tree/master/examples/svelte)
- [Test Svelte components using Vitest & Playwright](https://davipon.hashnode.dev/test-svelte-component-using-vitest-playwright)
- [Component testing with WebdriverIO](https://webdriver.io/docs/component-testing/svelte)

@ -2,7 +2,7 @@
question: Is there a router? question: Is there a router?
--- ---
The official routing library is [SvelteKit](https://kit.svelte.dev/), which is currently in beta. SvelteKit provides a filesystem router, server-side rendering (SSR), and hot module reloading (HMR) in one easy-to-use package. It shares similarities with Next.js for React. The official routing library is [SvelteKit](https://kit.svelte.dev/). SvelteKit provides a filesystem router, server-side rendering (SSR), and hot module reloading (HMR) in one easy-to-use package. It shares similarities with Next.js for React.
However, you can use any router lib you want. A lot of people use [page.js](https://github.com/visionmedia/page.js). There's also [navaid](https://github.com/lukeed/navaid), which is very similar. And [universal-router](https://github.com/kriasoft/universal-router), which is isomorphic with child routes, but without built-in history support. However, you can use any router lib you want. A lot of people use [page.js](https://github.com/visionmedia/page.js). There's also [navaid](https://github.com/lukeed/navaid), which is very similar. And [universal-router](https://github.com/kriasoft/universal-router), which is isomorphic with child routes, but without built-in history support.

@ -4,7 +4,7 @@ title: Basics
Welcome to the Svelte tutorial. This will teach you everything you need to know to build fast, small web applications easily. Welcome to the Svelte tutorial. This will teach you everything you need to know to build fast, small web applications easily.
You can also consult the [API docs](/docs) and the [examples](/examples), or — if you're impatient to start hacking on your machine locally — the [60-second quickstart](/blog/the-easiest-way-to-get-started). You can also consult the [API docs](/docs) and the [examples](/examples), or — if you're impatient to start hacking on your machine locally — the [60-second quickstart](/docs#getting-started).
## What is Svelte? ## What is Svelte?
@ -24,7 +24,7 @@ You'll need to have basic familiarity with HTML, CSS and JavaScript to understan
As you progress through the tutorial, you'll be presented with mini exercises designed to illustrate new features. Later chapters build on the knowledge gained in earlier ones, so it's recommended that you go from start to finish. If necessary, you can navigate via the dropdown above (click 'Introduction / Basics'). As you progress through the tutorial, you'll be presented with mini exercises designed to illustrate new features. Later chapters build on the knowledge gained in earlier ones, so it's recommended that you go from start to finish. If necessary, you can navigate via the dropdown above (click 'Introduction / Basics').
Each tutorial chapter will have a 'Show me' button that you can click if you get stuck following the instructions. Try not to rely on it too much; you will learn faster by figuring out where to put each suggested code block and manually typing it in to the editor. Each tutorial chapter will have a 'Show me' button that you can click if you get stuck following the instructions. Try not to rely on it too much; you will learn faster by figuring out where to put each suggested code block and manually typing it into the editor.
## Understanding components ## Understanding components

@ -2,9 +2,9 @@
title: Dynamic attributes title: Dynamic attributes
--- ---
Just like you can use curly braces to control text, you can use them to control element attributes. You can use curly braces to control element attributes, just like you use them to control text.
Our image is missing a `src` — let's add one: Our image is missing a `src` attribute — let's add one:
```html ```html
<img src={src}> <img src={src}>
@ -24,7 +24,6 @@ In this case, we're missing the `alt` attribute that describes the image for peo
We can use curly braces *inside* attributes. Try changing it to `"{name} dances."` — remember to declare a `name` variable in the `<script>` block. We can use curly braces *inside* attributes. Try changing it to `"{name} dances."` — remember to declare a `name` variable in the `<script>` block.
## Shorthand attributes ## Shorthand attributes
It's not uncommon to have an attribute where the name and value are the same, like `src={src}`. Svelte gives us a convenient shorthand for these cases: It's not uncommon to have an attribute where the name and value are the same, like `src={src}`. Svelte gives us a convenient shorthand for these cases:
@ -32,4 +31,3 @@ It's not uncommon to have an attribute where the name and value are the same, li
```html ```html
<img {src} alt="A man dances."> <img {src} alt="A man dances.">
``` ```

@ -4,13 +4,13 @@ title: Making an app
This tutorial is designed to get you familiar with the process of writing components. But at some point, you'll want to start writing components in the comfort of your own text editor. This tutorial is designed to get you familiar with the process of writing components. But at some point, you'll want to start writing components in the comfort of your own text editor.
First, you'll need to integrate Svelte with a build tool. There are officially maintained plugins for [Vite](https://vitejs.dev/), [Rollup](https://rollupjs.org) and [webpack](https://webpack.js.org/)... First, you'll need to integrate Svelte with a build tool. We recommend using [SvelteKit](https://kit.svelte.dev), which sets up [Vite](https://vitejs.dev/) with [vite-plugin-svelte](https://github.com/sveltejs/vite-plugin-svelte/) for you...
* [vite-plugin-svelte](https://github.com/sveltejs/vite-plugin-svelte) ```bash
* [rollup-plugin-svelte](https://github.com/sveltejs/rollup-plugin-svelte) npm create svelte@latest myapp
* [svelte-loader](https://github.com/sveltejs/svelte-loader) ```
...and a variety of [community-maintained ones](https://sveltesociety.dev/tools). There are also a number of [community-maintained integrations](https://sveltesociety.dev/tools).
Don't worry if you're relatively new to web development and haven't used these tools before. We've prepared a simple step-by-step guide, [Svelte for new developers](/blog/svelte-for-new-developers), which walks you through the process. Don't worry if you're relatively new to web development and haven't used these tools before. We've prepared a simple step-by-step guide, [Svelte for new developers](/blog/svelte-for-new-developers), which walks you through the process.

@ -2,9 +2,7 @@
title: Declarations title: Declarations
--- ---
Svelte automatically updates the DOM when your component's state changes. Often, some parts of a component's state need to be computed from *other* parts (such as a `fullname` derived from a `firstname` and a `lastname`), and recomputed whenever they change. Svelte's reactivity not only keeps the DOM in sync with your application's variables as shown in the previous section, it can also keep variables in sync with each other using reactive declarations. They look like this:
For these, we have *reactive declarations*. They look like this:
```js ```js
let count = 0; let count = 0;

@ -2,9 +2,11 @@
title: Updating arrays and objects title: Updating arrays and objects
--- ---
Because Svelte's reactivity is triggered by assignments, using array methods like `push` and `splice` won't automatically cause updates. For example, clicking the button doesn't do anything. Svelte's reactivity is triggered by assignments. Methods that mutate arrays or objects will not trigger updates by themselves.
One way to fix that is to add an assignment that would otherwise be redundant: In this example, clicking the "Add a number" button calls the `addNumber` function, which appends a number to the array but doesn't trigger the recalculation of `sum`.
One way to fix that is to assign `numbers` to itself to tell the compiler it has changed:
```js ```js
function addNumber() { function addNumber() {
@ -13,7 +15,7 @@ function addNumber() {
} }
``` ```
But there's a more idiomatic solution: You could also write this more concisely using the ES6 spread syntax:
```js ```js
function addNumber() { function addNumber() {
@ -21,7 +23,7 @@ function addNumber() {
} }
``` ```
You can use similar patterns to replace `pop`, `shift`, `unshift` and `splice`. The same rule applies to array methods such as `pop`, `shift`, and `splice` and to object methods such as `Map.set`, `Set.add`, etc.
Assignments to *properties* of arrays and objects — e.g. `obj.foo += 1` or `array[i] = x` — work the same way as assignments to the values themselves. Assignments to *properties* of arrays and objects — e.g. `obj.foo += 1` or `array[i] = x` — work the same way as assignments to the values themselves.
@ -31,11 +33,22 @@ function addNumber() {
} }
``` ```
A simple rule of thumb: the name of the updated variable must appear on the left hand side of the assignment. For example this... However, indirect assignments to references such as this...
```js ```js
const foo = obj.foo; const foo = obj.foo;
foo.bar = 'baz'; foo.bar = 'baz';
``` ```
or
```js
function quox(thing) {
thing.foo.bar = 'baz';
}
quox(obj);
```
...won't trigger reactivity on `obj.foo.bar`, unless you follow it up with `obj = obj`. ...won't trigger reactivity on `obj.foo.bar`, unless you follow it up with `obj = obj`.
A simple rule of thumb: the updated variable must directly appear on the left hand side of the assignment.

@ -10,7 +10,7 @@
<ul> <ul>
<!-- open each block --> <!-- open each block -->
<li><a target="_blank" href="https://www.youtube.com/watch?v={cat.id}"> <li><a target="_blank" href="https://www.youtube.com/watch?v={cat.id}" rel="noreferrer">
{cat.name} {cat.name}
</a></li> </a></li>
<!-- close each block --> <!-- close each block -->

@ -10,7 +10,7 @@
<ul> <ul>
{#each cats as { id, name }, i} {#each cats as { id, name }, i}
<li><a target="_blank" href="https://www.youtube.com/watch?v={id}"> <li><a target="_blank" href="https://www.youtube.com/watch?v={id}" rel="noreferrer">
{i + 1}: {name} {i + 1}: {name}
</a></li> </a></li>
{/each} {/each}

@ -7,7 +7,7 @@ If you need to loop over lists of data, use an `each` block:
```html ```html
<ul> <ul>
{#each cats as cat} {#each cats as cat}
<li><a target="_blank" href="https://www.youtube.com/watch?v={cat.id}"> <li><a target="_blank" href="https://www.youtube.com/watch?v={cat.id}" rel="noreferrer">
{cat.name} {cat.name}
</a></li> </a></li>
{/each} {/each}
@ -20,10 +20,10 @@ You can get the current *index* as a second argument, like so:
```html ```html
{#each cats as cat, i} {#each cats as cat, i}
<li><a target="_blank" href="https://www.youtube.com/watch?v={cat.id}"> <li><a target="_blank" href="https://www.youtube.com/watch?v={cat.id}" rel="noreferrer">
{i + 1}: {cat.name} {i + 1}: {cat.name}
</a></li> </a></li>
{/each} {/each}
``` ```
If you prefer, you can use destructuring — `each cats as { id, name }` — and replace `cat.id` and `cat.name` with `id` and `name`. If you prefer, you can use destructuring — `each cats as { id, name }` — and replace `cat.id` and `cat.name` with `id` and `name`.

@ -1,4 +1,6 @@
<script> <script>
import { onDestroy } from 'svelte';
const emojis = { const emojis = {
apple: "🍎", apple: "🍎",
banana: "🍌", banana: "🍌",
@ -12,6 +14,11 @@
// ...but the "emoji" variable is fixed upon initialisation of the component // ...but the "emoji" variable is fixed upon initialisation of the component
const emoji = emojis[name]; const emoji = emojis[name];
// observe in the console which entry is removed
onDestroy(() => {
console.log('thing destroyed: ' + name)
});
</script> </script>
<p> <p>

@ -1,4 +1,6 @@
<script> <script>
import { onDestroy } from 'svelte';
const emojis = { const emojis = {
apple: "🍎", apple: "🍎",
banana: "🍌", banana: "🍌",
@ -12,6 +14,11 @@
// ...but the "emoji" variable is fixed upon initialisation of the component // ...but the "emoji" variable is fixed upon initialisation of the component
const emoji = emojis[name]; const emoji = emojis[name];
// observe in the console which entry is removed
onDestroy(() => {
console.log('thing destroyed: ' + name)
});
</script> </script>
<p> <p>

@ -4,7 +4,7 @@ title: Keyed each blocks
By default, when you modify the value of an `each` block, it will add and remove items at the *end* of the block, and update any values that have changed. That might not be what you want. By default, when you modify the value of an `each` block, it will add and remove items at the *end* of the block, and update any values that have changed. That might not be what you want.
It's easier to show why than to explain. Click the 'Remove first thing' button a few times, and notice what happens: it does not remove the first `<Thing>` component, but rather the *last* DOM node. Then it updates the `name` value in the remaining DOM nodes, but not the emoji. It's easier to show why than to explain. Click to expand the `Console`, then click the 'Remove first thing' button a few times, and notice what happens: it does not remove the first `<Thing>` component, but rather the *last* DOM node. Then it updates the `name` value in the remaining DOM nodes, but not the emoji.
Instead, we'd like to remove only the first `<Thing>` component and its DOM node, and leave the others unaffected. Instead, we'd like to remove only the first `<Thing>` component and its DOM node, and leave the others unaffected.

@ -19,7 +19,7 @@ Most web applications have to deal with asynchronous data at some point. Svelte
If you know that your promise can't reject, you can omit the `catch` block. You can also omit the first block if you don't want to show anything until the promise resolves: If you know that your promise can't reject, you can omit the `catch` block. You can also omit the first block if you don't want to show anything until the promise resolves:
```html ```html
{#await promise then value} {#await promise then number}
<p>the value is {value}</p> <p>the number is {number}</p>
{/await} {/await}
``` ```

@ -10,7 +10,7 @@
{#if yes} {#if yes}
<p>Thank you. We will bombard your inbox and sell your personal details.</p> <p>Thank you. We will bombard your inbox and sell your personal details.</p>
{:else} {:else}
<p>You must opt in to continue. If you're not paying, you're the product.</p> <p>You must opt-in to continue. If you're not paying, you're the product.</p>
{/if} {/if}
<button disabled={!yes}> <button disabled={!yes}>

@ -10,7 +10,7 @@
{#if yes} {#if yes}
<p>Thank you. We will bombard your inbox and sell your personal details.</p> <p>Thank you. We will bombard your inbox and sell your personal details.</p>
{:else} {:else}
<p>You must opt in to continue. If you're not paying, you're the product.</p> <p>You must opt-in to continue. If you're not paying, you're the product.</p>
{/if} {/if}
<button disabled={!yes}> <button disabled={!yes}>

@ -1,8 +1,7 @@
--- ---
title: Textarea inputs title: Textarea inputs
--- ---
The `<textarea>` element behaves similarly to a text input in Svelte — use `bind:value` to create a two-way binding between the `<textarea>` content and the `value` variable:
The `<textarea>` element behaves similarly to a text input in Svelte — use `bind:value`:
```html ```html
<textarea bind:value={value}></textarea> <textarea bind:value={value}></textarea>
@ -14,4 +13,4 @@ In cases like these, where the names match, we can also use a shorthand form:
<textarea bind:value></textarea> <textarea bind:value></textarea>
``` ```
This applies to all bindings, not just textareas. This applies to all bindings, not just textareas.

@ -4,7 +4,7 @@
let photos = []; let photos = [];
onMount(async () => { onMount(async () => {
const res = await fetch(`https://jsonplaceholder.typicode.com/photos?_limit=20`); const res = await fetch(`/tutorial/api/album`);
photos = await res.json(); photos = await res.json();
}); });
</script> </script>

@ -15,7 +15,7 @@ We'll add an `onMount` handler that loads some data over the network:
let photos = []; let photos = [];
onMount(async () => { onMount(async () => {
const res = await fetch(`https://jsonplaceholder.typicode.com/photos?_limit=20`); const res = await fetch(`/tutorial/api/album`);
photos = await res.json(); photos = await res.json();
}); });
</script> </script>

@ -33,6 +33,7 @@
svg { svg {
width: 100%; width: 100%;
height: 100%; height: 100%;
margin: -8px;
} }
circle { circle {
fill: #ff3e00; fill: #ff3e00;

@ -24,4 +24,6 @@ let coords = spring({ x: 50, y: 50 }, {
}); });
``` ```
Waggle your mouse around, and try dragging the sliders to get a feel for how they affect the spring's behaviour. Notice that you can adjust the values while the spring is still in motion. Waggle your mouse around, and try dragging the sliders to get a feel for how they affect the spring's behaviour. Notice that you can adjust the values while the spring is still in motion.
Consult the [API reference](/docs#run-time-svelte-motion-spring) for more information.

@ -18,6 +18,7 @@ export function longpress(node, duration) {
return { return {
destroy() { destroy() {
clearTimeout(timer);
node.removeEventListener('mousedown', handleMousedown); node.removeEventListener('mousedown', handleMousedown);
node.removeEventListener('mouseup', handleMouseup); node.removeEventListener('mouseup', handleMouseup);
} }

@ -21,6 +21,7 @@ export function longpress(node, duration) {
duration = newDuration; duration = newDuration;
}, },
destroy() { destroy() {
clearTimeout(timer);
node.removeEventListener('mousedown', handleMousedown); node.removeEventListener('mousedown', handleMousedown);
node.removeEventListener('mouseup', handleMouseup); node.removeEventListener('mouseup', handleMouseup);
} }

@ -10,7 +10,7 @@
<ul> <ul>
<li> <li>
<Project <Project
title="Add Typescript support" title="Add TypeScript support"
tasksCompleted={25} tasksCompleted={25}
totalTasks={57} totalTasks={57}
> >

@ -10,7 +10,7 @@
<ul> <ul>
<li> <li>
<Project <Project
title="Add Typescript support" title="Add TypeScript support"
tasksCompleted={25} tasksCompleted={25}
totalTasks={57} totalTasks={57}
> >

@ -10,7 +10,7 @@
} }
</script> </script>
<span class:expanded on:click={toggle}>{name}</span> <button class:expanded on:click={toggle}>{name}</button>
{#if expanded} {#if expanded}
<ul> <ul>
@ -27,12 +27,14 @@
{/if} {/if}
<style> <style>
span { button {
padding: 0 0 0 1.5em; padding: 0 0 0 1.5em;
background: url(/tutorial/icons/folder.svg) 0 0.1em no-repeat; background: url(/tutorial/icons/folder.svg) 0 0.1em no-repeat;
background-size: 1em 1em; background-size: 1em 1em;
font-weight: bold; font-weight: bold;
cursor: pointer; cursor: pointer;
border: none;
margin: 0;
} }
.expanded { .expanded {

@ -10,7 +10,7 @@
} }
</script> </script>
<span class:expanded on:click={toggle}>{name}</span> <button class:expanded on:click={toggle}>{name}</button>
{#if expanded} {#if expanded}
<ul> <ul>
@ -27,12 +27,14 @@
{/if} {/if}
<style> <style>
span { button {
padding: 0 0 0 1.5em; padding: 0 0 0 1.5em;
background: url(/tutorial/icons/folder.svg) 0 0.1em no-repeat; background: url(/tutorial/icons/folder.svg) 0 0.1em no-repeat;
background-size: 1em 1em; background-size: 1em 1em;
font-weight: bold; font-weight: bold;
cursor: pointer; cursor: pointer;
border: none;
margin: 0;
} }
.expanded { .expanded {

@ -1,10 +1,10 @@
<script> <script>
let key; let key;
let keyCode; let code;
function handleKeydown(event) { function handleKeydown(event) {
key = event.key; key = event.key;
keyCode = event.keyCode; code = event.code;
} }
</script> </script>
@ -13,7 +13,7 @@
<div style="text-align: center"> <div style="text-align: center">
{#if key} {#if key}
<kbd>{key === ' ' ? 'Space' : key}</kbd> <kbd>{key === ' ' ? 'Space' : key}</kbd>
<p>{keyCode}</p> <p>{code}</p>
{:else} {:else}
<p>Focus this window and press any key</p> <p>Focus this window and press any key</p>
{/if} {/if}
@ -39,4 +39,4 @@
border-bottom: 5px solid rgba(0, 0, 0, 0.2); border-bottom: 5px solid rgba(0, 0, 0, 0.2);
color: #555; color: #555;
} }
</style> </style>

@ -1,10 +1,10 @@
<script> <script>
let key; let key;
let keyCode; let code;
function handleKeydown(event) { function handleKeydown(event) {
key = event.key; key = event.key;
keyCode = event.keyCode; code = event.code;
} }
</script> </script>
@ -13,7 +13,7 @@
<div style="text-align: center"> <div style="text-align: center">
{#if key} {#if key}
<kbd>{key === ' ' ? 'Space' : key}</kbd> <kbd>{key === ' ' ? 'Space' : key}</kbd>
<p>{keyCode}</p> <p>{code}</p>
{:else} {:else}
<p>Focus this window and press any key</p> <p>Focus this window and press any key</p>
{/if} {/if}

@ -4,22 +4,24 @@
export let todo; export let todo;
let div; let button;
afterUpdate(() => { afterUpdate(() => {
flash(div); flash(button);
}); });
</script> </script>
<!-- the text will flash red whenever <!-- the text will flash red whenever
the `todo` object changes --> the `todo` object changes -->
<div bind:this={div} on:click> <button bind:this={button} type="button" on:click>
{todo.done ? '👍': ''} {todo.text} {todo.done ? '👍': ''} {todo.text}
</div> </button>
<style> <style>
div { button {
all: unset;
display: block;
cursor: pointer; cursor: pointer;
line-height: 1.5; line-height: 1.5;
} }
</style> </style>

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