matthewp

function decorate(tag, template) {
  customElements.define(tag, class extends HTMLElement {
    constructor() {
      super();
      this.attachShadow({ mode: 'open' });
    }
    
    connectedCallback() {
      let root = this.shadowRoot;
      if(!root.firstChild) {

addyosmani

/*

Flexbox CSS helpers from the Polymer team. Extracted from https://github.com/PolymerElements/iron-flex-layout for use as just CSS.
Docs: https://elements.polymer-project.org/guides/flex-layout

@license
Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt

developit

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) {