WebComponents001

Sample1： ShadowDom 隔离style，替换显示内容

<button>Hello, world!</button>
<script>
var host = document.querySelector('button');
var root = host.createShadowRoot();
root.innerHTML = '<style>div{background-color : blue;}</style> <div>Hi, you are great!</div>';
</script>
<style>
    div {
        background-color : green;
    }
</style>
<div>Outside Element</div>

 Sample 2: 通过Template给shadow Dom设置内容， 注意template中的script的作用域是全局的，style的作用域是shadow dom局部

<button>Hello, world!</button>
<div>Outside Element</div>
<template id="t1">
    <style>div{background-color : blue;}</style> 
    <div>Hi, you are great!</div>
    <script>
    //此处脚本不会被执行
        var d = document.querySelector('div');
        d.onclick = function(){
            alert("Hi");
        }
    </script>
</template>
<script>
var host = document.querySelector('button');
var root = host.createShadowRoot();
var t = document.querySelector("#t1");
//通过innerHTML给shadow dom赋值，不会执行template中的script
root.innerHTML = t.innerHTML; 
</script>
<style>
    div {
        background-color : green;
    }
</style>

 Sample 3: 为template中的content嵌入子节点。子节点的style受外部css的直接控制，但是会继承shadow dom中父节点的style

<div id="hostNode"><div>Hello, world!</div></div>
<div>Outside Element</div>
<template id="t1">
    <style>div{background-color : blue; font-size: 30px;}</style> 
    <div>Hi, you are great!</div>
    <div>
        <content></content>
    </div>
</template>
<script>
var host = document.querySelector('#hostNode');
var root = host.createShadowRoot();
var t = document.querySelector("#t1");
var content = t.content;
root.appendChild(document.importNode(content,true));
</script>
<style>
    div {
        background-color : green;
            font-size: 40px;
    }
    #mytext {
        background-color : red;
    }
</style>

 sample 4：带有select的content

<div id="hostNode">
    <div class="kk">Hello, kk world!</div>
    <div class="hh">Hello, hh world!</div>
</div>
<div>Outside Element</div>
<template id="t1">
    <style>div{background-color : blue; font-size: 30px;}</style> 
    <div>Hi, you are great!</div>
    <div>
        <content select=".hh"></content>
        分割<br>
        <content select=".kk"></content>
    </div>
</template>
<script>
var host = document.querySelector('#hostNode');
var root = host.createShadowRoot();
var t = document.querySelector("#t1");
var content = t.content;
root.appendChild(document.importNode(content,true));
</script>
<style>
    div {
        background-color : green;
        font-size: 40px;
    }
    #mytext {
        background-color : red;
    }
</style>