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Preact + Web Components = <333 Demo: http://www.webpackbin.com/VJyU9wK5W
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import { h, Component } from 'preact'; | |
import Markup from 'preact-markup'; | |
import register from './preact-custom-element'; | |
// just a proxy component: WC -> Preact -> WC | |
const A = () => <x-b foo="initial foo from <x-a>" />; | |
// stateful component that can re-render | |
class B extends Component { | |
render(props, state) { | |
return ( | |
<div> | |
<label style={{ display:'block' }}> | |
foo= | |
<input onInput={this.linkState('foo')} /> | |
</label> | |
<x-c foo={state.foo || props.foo} /> | |
</div> | |
); | |
} | |
} | |
// accepts props (as attributes) from B (<x-b>) | |
const C = ({ foo }) => ( | |
<span>I am {'<x-c>'}. I got passed foo = <code>{foo}</code></span> | |
); | |
// register stuff (or do it inline above) | |
register(A, 'x-a'); | |
register(B, 'x-b'); | |
register(C, 'x-c'); | |
// WC on the outside: | |
document.body.innerHTML = '<x-a></x-a>'; |
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import { h, render } from 'preact'; | |
const Empty = () => null; | |
export default function register(Component, tagName) { | |
let prototype = Object.create(HTMLElement.prototype); | |
prototype._vdomComponent = Component; | |
prototype.attachedCallback = prototype.attributeChangedCallback = renderElement; | |
prototype.detachedCallback = unRenderElement; | |
return document.registerElement( | |
tagName || Component.displayName || Component.name, | |
{ prototype } | |
); | |
} | |
function renderElement() { | |
this._root = render( | |
toVdom(this, this._vdomComponent), | |
this.shadowRoot || this.createShadowRoot(), | |
this._root | |
); | |
} | |
function unRenderElement() { | |
render(h(Empty), this.shadowRoot, this._root); | |
} | |
function toVdom(element, nodeName) { | |
if (element.nodeType===3) return element.nodeValue; | |
if (element.nodeType!==1) return null; | |
let children=[], props={}, i=0, a=element.attributes, cn=element.childNodes; | |
for (i=a.length; i--; ) props[a[i].name] = a[i].value; | |
for (i=cn.length; i--; ) children[i] = toVdom(cn[i]); | |
return h(nodeName || element.nodeName.toLowerCase(), props, children); | |
} |
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@RendeCode, perfect, I am glad but keep in mind this example will not work anymore at all because of https://developer.mozilla.org/en-US/docs/Web/API/Document/registerElement (This API was removed from browsers) and you should follow this https://preactjs.com/guide/v10/web-components/