- clarify that a callback prop means passing a function
- enhance the example so that a parameter is passed and the prop is explicitly invoked to visualize the concept better
closes#11671
In Svelte 3 and 4, components were classes under the hood, and the base class was `SvelteComponent`. This class was also used in language tools to properly type check the template code.
In Svelte 5, components are functions. To give people a way to extend them programmatically, it would be good to expose the actual shape of components. This is why this PR introduces a new `Component` type.
For backwards compatibility reasons, we can't just get rid of the old class-based types. We also need to ensure that language tools can work with both the new and old types: There are many libraries out there that provide `d.ts` files with type definitions written using the class types - these should not error.
That's why there's an accompagning language tools PR (https://github.com/sveltejs/language-tools/pull/2380) that's doing the heavy lifting: Instead of generating classes, it now generates a constant and an interfaces and uses Typescript's declaration merging feature to provide both so we can declare a component export as being both a class and a function. That ensures that people can still instantiate them with `new` (which they can do if they use the `legacy.componentApi` compiler option), and it also ensure we don't need to adjust any other code generation mechanisms in language tools yet - from a language tools perspective, classes are still the norm. But through exposing the default export as being _also_ callable as a function we can in a future Svelte version, where classes/the Svelte 4 syntax are removed completely, seamlessly switch over to using functions in the code generation, too, and the `d.ts` files generated up until that point will support it because of the dual shape. This way we have both backwards and forwards compatibility.
* breaking: disallow string literal values in `<svelte:element this="...">`
* note breaking change
* Update sites/svelte-5-preview/src/routes/docs/content/03-appendix/02-breaking-changes.md
Co-authored-by: Jeremiasz Major <jrh.mjr@gmail.com>
* prettier
* make invalid `<svelte:element this>` a warning instead of an error (#11641)
* make it a warning instead of an error
* format
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Co-authored-by: Jeremiasz Major <jrh.mjr@gmail.com>
* feat: add $state.is rune
* fix type
* tweak docs
* may as well update the test case to match the docs
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
* feat: make autocomplete more robust
* handle `$inspect(...).with(...)` special case
* autocomplete imports
* only allow $props at the top level of .svelte files
* only autocomplete runes in svelte files
Provides a migration function, exported as `migrate` from `svelte/compiler`, which tries its best to automatically migrate towards runes, render tags (instead of slots) and event attributes (instead of event handlers)
The preview REPL was updated with a migrate button so people can try it out in the playground.
closes#9239
* chore: directly export function in non-HMR mode
* remove some more noise
* update snapshots
* Update sites/svelte-5-preview/src/lib/workers/compiler/index.js
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
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Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
* fix: mark `accessors` and `immutable` as deprecated
* add warnings for deprecated <svelte:options> attributes
* disable accessors in runes mode
* update tests
* tidy up
* the hell?
* regenerate types
* if I would get a dollar for every windows bug I fix I would be a millionaire by now
* return instance _and_ props in runes mode, move flushSync into shared code, don't set accessors in runes mode
* goddammit
* note breaking change
* fix
* regenerate messages
* Revert "return instance _and_ props in runes mode, move flushSync into shared code, don't set accessors in runes mode"
This reverts commit a47827e57d.
* pass instance to tests
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Co-authored-by: Simon Holthausen <simon.holthausen@vercel.com>
* breaking: disallow binding to component exports in runes mode
Svelte 4 allowed you to have `export const foo = ..` in component A and then do `<A bind:foo />`. This is confusing because it's not clear whether the binding is for a property or an export, and we have to sanitize rest props from the export bindings.
This PR therefore introduces a breaking change in runes mode: You cannot bind to these exports anymore. Instead use `<A bind:this={a} />` and then do `a.foo` - makes things easier to reason about.
* Update sites/svelte-5-preview/src/routes/docs/content/03-appendix/02-breaking-changes.md
Co-authored-by: Rich Harris <rich.harris@vercel.com>
* tweak messages
* fix tests
* use component.name
* oops
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
* feat: hot module reloading support for Svelte 5
* fix lockfile
* tweaks
* types
* lint
* lint
* tweaks
* add hmr flag
* tweak
* tweaks
* move HMR logic into its own module
* simplify
* tidy up types
* fix test
* lint
* need some indirection here or references break
* prevent transitions during HMR update
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
- don't throw a dev time error when binding to an export (fixes#11008)
- remove bindings that are for component exports
- throw an error when using a component export with the same name as a property
* feat: take form resets into account for two way bindings
When resetting a form, the value of the inputs within it get out of sync with the bound value of those inputs. This PR introduces a reset listener on the parent form to reset the value in that case
closes#2659
* slightly different approach
* tweaks, test
* this is a breaking change, strictly speaking
* bind:files
* use capture phase
* tweak wording
* use promise, explain
* feat: adds reactive Map class to svelte/reactivity
* add docs
* add docs
* add test case
* types
* make reactive set better
* address feedback
* fix typo
* more efficient initialisation
* this is incorrect, it would fail if given a map for example
* increase consistency (with e.g. proxy.js)
* tidy up
* Revert "more efficient initialisation"
This reverts commit 29d4a8078b.
* efficient initialization, without bugs this time
* convention
* delete make_iterable
* update changeset
* efficient initialization
* avoid generator functions
* Update sites/svelte-5-preview/src/routes/docs/content/01-api/02-runes.md
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
Co-authored-by: Rich Harris <richard.a.harris@gmail.com>
Simon H
Rich Harris
Dominic Gannaway
Matei Trandafir
이요
Luke Warlow
Ben M
Tee Ming
Ignatius Bagus
Rich Harris
Antonio Sarcevic