w3c标准 H5规范中规定：自定义元素必须至少包含一个连字符，即最简形式也要这样a-b
比如：
<hello></hello>这样会出错
<hell-o></hell-o>这样才对
下边是demo代码
index.html:
<!DOCTYPE html >
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="import" href="demo.html">
<title>html自定义标签</title>
</head>
<body>
<hell-o></hell-o>
<h1>abc</h1>
</body>
</html>
demo.html:
<!DOCTYPE html >
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>demo</title>
</head>
<body>
<template id="hello">
<style type="text/css">
h1{color:red;}
</style>
<h1>hello</h1>
</template>
<script type="text/javascript">
var indexDoc=document,
helloDoc=(indexDoc._currentScript || indexDoc.currentScript).ownerDocument,
tmpl=helloDoc.querySelector('#hello'),
HelloProto=Object.create(HTMLElement.prototype);
HelloProto.createdCallback=function(){
var roots=this.createShadowRoot();
roots.appendChild(indexDoc.importNode(tmpl.content,true));
};
var Hello=indexDoc.registerElement('hell-o',{
prototype:HelloProto
});
</script>
</body>
</html>
