bash
npm install @polymer/polymer
html
<!-- my-element.html -->
<dom-module id="my-element">
<template>
<style>
:host {
display: block;
padding: 16px;
background-color: #f0f0f0;
}
</style>
<h2>Hello, Polymer!</h2>
</template>
<script>
class MyElement extends Polymer.Element {
static get is() { return 'my-element'; }
}
customElements.define(MyElement.is, MyElement);
</script>
</dom-module>
script
import {html, PolymerElement} from '@polymer/polymer/polymer-element.js';
html
<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<script type="module" src="app.js"></script>
</head>
<body>
<my-element></my-element>
</body>
</html>
