add action chapter, plus a couple of placeholders

pull/2179/head
Richard Harris 7 years ago
parent ee3ef5bca7
commit 26b3e5171b

@ -0,0 +1,146 @@
<script>
import { quintOut } from 'svelte/easing';
import crossfade from './crossfade.js'; // TODO put this in svelte/transition!
const { send, receive } = crossfade({
fallback(node, params) {
const style = getComputedStyle(node);
const transform = style.transform === 'none' ? '' : style.transform;
return {
duration: 600,
easing: quintOut,
css: t => `
transform: ${transform} scale(${t});
opacity: ${t}
`
};
}
});
let todos = [
{ id: 1, done: false, description: 'write some docs' },
{ id: 2, done: false, description: 'start writing JSConf talk' },
{ id: 3, done: true, description: 'buy some milk' },
{ id: 4, done: false, description: 'mow the lawn' },
{ id: 5, done: false, description: 'feed the turtle' },
{ id: 6, done: false, description: 'fix some bugs' },
];
let uid = todos.length + 1;
function add(input) {
const todo = {
id: uid++,
done: false,
description: input.value
};
todos = [todo, ...todos];
input.value = '';
}
function remove(todo) {
todos = todos.filter(t => t !== todo);
}
function handleKeydown(event) {
if (event.which === 13) {
addTodo(event.target);
}
}
</script>
<style>
.new-todo {
font-size: 1.4em;
width: 100%;
margin: 2em 0 1em 0;
}
.board {
max-width: 36em;
margin: 0 auto;
}
.left, .right {
float: left;
width: 50%;
padding: 0 1em 0 0;
box-sizing: border-box;
}
h2 {
font-size: 2em;
font-weight: 200;
user-select: none;
}
label {
top: 0;
left: 0;
display: block;
font-size: 1em;
line-height: 1;
padding: 0.5em;
margin: 0 auto 0.5em auto;
border-radius: 2px;
background-color: #eee;
user-select: none;
}
input { margin: 0 }
.right label {
background-color: rgb(180,240,100);
}
button {
float: right;
height: 1em;
box-sizing: border-box;
padding: 0 0.5em;
line-height: 1;
background-color: transparent;
border: none;
color: rgb(170,30,30);
opacity: 0;
transition: opacity 0.2s;
}
label:hover button {
opacity: 1;
}
</style>
<div class='board'>
<input class="new-todo" placeholder="what needs to be done?" on:enter={add}>
<div class='left'>
<h2>todo</h2>
{#each todos.filter(t => !t.done) as todo (todo.id)}
<label
in:receive="{{key: todo.id}}"
out:send="{{key: todo.id}}"
>
<input type=checkbox bind:checked={todo.done}>
{todo.description}
<button on:click="{() => remove(todo)}">x</button>
</label>
{/each}
</div>
<div class='right'>
<h2>done</h2>
{#each todos.filter(t => t.done) as todo (todo.id)}
<label
in:receive="{{key: todo.id}}"
out:send="{{key: todo.id}}"
>
<input type=checkbox bind:checked={todo.done}>
{todo.description}
<button on:click="{() => remove(todo)}">x</button>
</label>
{/each}
</div>
</div>

@ -0,0 +1,65 @@
import { quintOut } from 'svelte/easing';
export default function crossfade({ send, receive, fallback }) {
let requested = new Map();
let provided = new Map();
function crossfade(from, node) {
const to = node.getBoundingClientRect();
const dx = from.left - to.left;
const dy = from.top - to.top;
const style = getComputedStyle(node);
const transform = style.transform === 'none' ? '' : style.transform;
return {
duration: 400,
easing: quintOut,
css: (t, u) => `
opacity: ${t};
transform: ${transform} translate(${u * dx}px,${u * dy}px);
`
};
}
return {
send(node, params) {
provided.set(params.key, {
rect: node.getBoundingClientRect()
});
return () => {
if (requested.has(params.key)) {
const { rect } = requested.get(params.key);
requested.delete(params.key);
return crossfade(rect, node);
}
// if the node is disappearing altogether
// (i.e. wasn't claimed by the other list)
// then we need to supply an outro
provided.delete(params.key);
return fallback(node, params);
};
},
receive(node, params) {
requested.set(params.key, {
rect: node.getBoundingClientRect()
});
return () => {
if (provided.has(params.key)) {
const { rect } = provided.get(params.key);
provided.delete(params.key);
return crossfade(rect, node);
}
requested.delete(params.key);
return fallback(node, params);
};
}
};
}

@ -0,0 +1,146 @@
<script>
import { quintOut } from 'svelte/easing';
import crossfade from './crossfade.js'; // TODO put this in svelte/transition!
const { send, receive } = crossfade({
fallback(node, params) {
const style = getComputedStyle(node);
const transform = style.transform === 'none' ? '' : style.transform;
return {
duration: 600,
easing: quintOut,
css: t => `
transform: ${transform} scale(${t});
opacity: ${t}
`
};
}
});
let todos = [
{ id: 1, done: false, description: 'write some docs' },
{ id: 2, done: false, description: 'start writing JSConf talk' },
{ id: 3, done: true, description: 'buy some milk' },
{ id: 4, done: false, description: 'mow the lawn' },
{ id: 5, done: false, description: 'feed the turtle' },
{ id: 6, done: false, description: 'fix some bugs' },
];
let uid = todos.length + 1;
function add(input) {
const todo = {
id: uid++,
done: false,
description: input.value
};
todos = [todo, ...todos];
input.value = '';
}
function remove(todo) {
todos = todos.filter(t => t !== todo);
}
function handleKeydown(event) {
if (event.which === 13) {
addTodo(event.target);
}
}
</script>
<style>
.new-todo {
font-size: 1.4em;
width: 100%;
margin: 2em 0 1em 0;
}
.board {
max-width: 36em;
margin: 0 auto;
}
.left, .right {
float: left;
width: 50%;
padding: 0 1em 0 0;
box-sizing: border-box;
}
h2 {
font-size: 2em;
font-weight: 200;
user-select: none;
}
label {
top: 0;
left: 0;
display: block;
font-size: 1em;
line-height: 1;
padding: 0.5em;
margin: 0 auto 0.5em auto;
border-radius: 2px;
background-color: #eee;
user-select: none;
}
input { margin: 0 }
.right label {
background-color: rgb(180,240,100);
}
button {
float: right;
height: 1em;
box-sizing: border-box;
padding: 0 0.5em;
line-height: 1;
background-color: transparent;
border: none;
color: rgb(170,30,30);
opacity: 0;
transition: opacity 0.2s;
}
label:hover button {
opacity: 1;
}
</style>
<div class='board'>
<input class="new-todo" placeholder="what needs to be done?" on:enter={add}>
<div class='left'>
<h2>todo</h2>
{#each todos.filter(t => !t.done) as todo (todo.id)}
<label
in:receive="{{key: todo.id}}"
out:send="{{key: todo.id}}"
>
<input type=checkbox bind:checked={todo.done}>
{todo.description}
<button on:click="{() => remove(todo)}">x</button>
</label>
{/each}
</div>
<div class='right'>
<h2>done</h2>
{#each todos.filter(t => t.done) as todo (todo.id)}
<label
in:receive="{{key: todo.id}}"
out:send="{{key: todo.id}}"
>
<input type=checkbox bind:checked={todo.done}>
{todo.description}
<button on:click="{() => remove(todo)}">x</button>
</label>
{/each}
</div>
</div>

@ -0,0 +1,65 @@
import { quintOut } from 'svelte/easing';
export default function crossfade({ send, receive, fallback }) {
let requested = new Map();
let provided = new Map();
function crossfade(from, node) {
const to = node.getBoundingClientRect();
const dx = from.left - to.left;
const dy = from.top - to.top;
const style = getComputedStyle(node);
const transform = style.transform === 'none' ? '' : style.transform;
return {
duration: 400,
easing: quintOut,
css: (t, u) => `
opacity: ${t};
transform: ${transform} translate(${u * dx}px,${u * dy}px);
`
};
}
return {
send(node, params) {
provided.set(params.key, {
rect: node.getBoundingClientRect()
});
return () => {
if (requested.has(params.key)) {
const { rect } = requested.get(params.key);
requested.delete(params.key);
return crossfade(rect, node);
}
// if the node is disappearing altogether
// (i.e. wasn't claimed by the other list)
// then we need to supply an outro
provided.delete(params.key);
return fallback(node, params);
};
},
receive(node, params) {
requested.set(params.key, {
rect: node.getBoundingClientRect()
});
return () => {
if (provided.has(params.key)) {
const { rect } = provided.get(params.key);
provided.delete(params.key);
return crossfade(rect, node);
}
requested.delete(params.key);
return fallback(node, params);
};
}
};
}

@ -0,0 +1,5 @@
---
title: The animate directive
---
TODO fix https://github.com/sveltejs/svelte/issues/2159 before working on `animate`

@ -0,0 +1,3 @@
{
"title": "Animations"
}

@ -0,0 +1,47 @@
<script>
import { spring } from 'svelte/motion';
const coords = spring({ x: 0, y: 0 }, {
stiffness: 0.2,
damping: 0.4
});
function handlePanStart() {
coords.stiffness = coords.damping = 1;
}
function handlePanMove(event) {
coords.update($coords => ({
x: $coords.x + event.detail.dx,
y: $coords.y + event.detail.dy
}));
}
function handlePanEnd(event) {
coords.stiffness = 0.2;
coords.damping = 0.4;
coords.set({ x: 0, y: 0 });
}
</script>
<style>
.box {
--width: 100px;
--height: 100px;
position: absolute;
width: var(--width);
height: var(--height);
left: calc(50% - var(--width) / 2);
top: calc(50% - var(--height) / 2);
border-radius: 4px;
background-color: #ff3e00;
cursor: move;
}
</style>
<div class="box"
on:panstart={handlePanStart}
on:panmove={handlePanMove}
on:panend={handlePanEnd}
style="transform: translate({$coords.x}px,{$coords.y}px)"
></div>

@ -0,0 +1,9 @@
export function pannable(node) {
// setup work goes here...
return {
destroy() {
// ...cleanup goes here
}
};
}

@ -0,0 +1,49 @@
<script>
import { spring } from 'svelte/motion';
import { pannable } from './pannable.js';
const coords = spring({ x: 0, y: 0 }, {
stiffness: 0.2,
damping: 0.4
});
function handlePanStart() {
coords.stiffness = coords.damping = 1;
}
function handlePanMove(event) {
coords.update($coords => ({
x: $coords.x + event.detail.dx,
y: $coords.y + event.detail.dy
}));
}
function handlePanEnd(event) {
coords.stiffness = 0.2;
coords.damping = 0.4;
coords.set({ x: 0, y: 0 });
}
</script>
<style>
.box {
--width: 100px;
--height: 100px;
position: absolute;
width: var(--width);
height: var(--height);
left: calc(50% - var(--width) / 2);
top: calc(50% - var(--height) / 2);
border-radius: 4px;
background-color: #ff3e00;
cursor: move;
}
</style>
<div class="box"
use:pannable
on:panstart={handlePanStart}
on:panmove={handlePanMove}
on:panend={handlePanEnd}
style="transform: translate({$coords.x}px,{$coords.y}px)"
></div>

@ -0,0 +1,47 @@
export function pannable(node) {
let x;
let y;
function handleMousedown(event) {
x = event.clientX;
y = event.clientY;
node.dispatchEvent(new CustomEvent('panstart', {
detail: { x, y }
}));
window.addEventListener('mousemove', handleMousemove);
window.addEventListener('mouseup', handleMouseup);
}
function handleMousemove(event) {
const dx = event.clientX - x;
const dy = event.clientY - y;
x = event.clientX;
y = event.clientY;
node.dispatchEvent(new CustomEvent('panmove', {
detail: { x, y, dx, dy }
}));
}
function handleMouseup(event) {
x = event.clientX;
y = event.clientY;
node.dispatchEvent(new CustomEvent('panend', {
detail: { x, y }
}));
window.removeEventListener('mousemove', handleMousemove);
window.removeEventListener('mouseup', handleMouseup);
}
node.addEventListener('mousedown', handleMousedown);
return {
destroy() {
node.removeEventListener('mousedown', handleMousedown);
}
};
}

@ -0,0 +1,87 @@
---
title: The use directive
---
Actions are essentially element-level lifecycle functions. They're useful for things like:
* interfacing with third-party libraries
* lazy-loaded images
* tooltips
* adding custom event handlers
In this app, we want to make the orange box 'pannable'. It has event handlers for the `panstart`, `panmove` and `panend` events, but these aren't native DOM events. We have to dispatch them ourselves. First, import the `pannable` function...
```js
import { pannable } from './pannable.js';
```
...then use it with the element:
```html
<div class="box"
use:pannable
on:panstart={handlePanStart}
on:panmove={handlePanMove}
on:panend={handlePanEnd}
style="transform: translate({$coords.x}px,{$coords.y}px)"
></div>
```
Open the `pannable.js` file. Like transition functions, an action function receives a `node` and some optional parameters, and returns an action object. That object must have a `destroy` function, which is called when the element is unmounted.
We want to fire `panstart` event when the user mouses down on the element, `panmove` events (with `dx` and `dy` properties showing how far the mouse moved) when they drag it, and `panend` events when they mouse up. One possible implementation looks like this:
```js
export function pannable(node) {
let x;
let y;
function handleMousedown(event) {
x = event.clientX;
y = event.clientY;
node.dispatchEvent(new CustomEvent('panstart', {
detail: { x, y }
}));
window.addEventListener('mousemove', handleMousemove);
window.addEventListener('mouseup', handleMouseup);
}
function handleMousemove(event) {
const dx = event.clientX - x;
const dy = event.clientY - y;
x = event.clientX;
y = event.clientY;
node.dispatchEvent(new CustomEvent('panmove', {
detail: { x, y, dx, dy }
}));
}
function handleMouseup(event) {
x = event.clientX;
y = event.clientY;
node.dispatchEvent(new CustomEvent('panend', {
detail: { x, y }
}));
window.removeEventListener('mousemove', handleMousemove);
window.removeEventListener('mouseup', handleMouseup);
}
node.addEventListener('mousedown', handleMousedown);
return {
destroy() {
node.removeEventListener('mousedown', handleMousedown);
}
};
}
```
Update the `pannable` function and try moving the box around.
> This implementation is for demonstration purposes — a more complete one would also consider touch events.

@ -0,0 +1,5 @@
---
title: Adding parameters
---
TODO example with Prism highlighting

@ -0,0 +1,3 @@
{
"title": "Actions"
}

@ -85,6 +85,7 @@ Maybe lifecycle should go first, since we're using `onMount` in the `this` demo?
* [ ] custom stores
* [ ] `bind:value={$foo}`
* [ ] `$foo += 1` (if we implement it)
* [ ] Adapting Immer, Redux, Microstates, xstate etc
## Motion
@ -119,7 +120,7 @@ Maybe lifecycle should go first, since we're using `onMount` in the `this` demo?
## use: directive
* [ ] `use:foo`
* [x] `use:foo`
* [ ] `use:foo={bar}`
## class: directive

@ -89,7 +89,7 @@
function handle_change(event) {
completed = event.detail.components.every((file, i) => {
const expected = chapter.app_b[i];
return (
return expected && (
file.name === expected.name &&
file.type === expected.type &&
file.source === expected.source

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