<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>模拟Vue.assetRegisters(Vue)</title>
</head>
<body>
<div id="app"></div>
<template id='Comp'>
<div>
haha
</div>
</template>
</body>
<script>
const ASSET_TYPES = ['directive','component','filter']
// 判断是否是原始的Object
const _toString = Object.prototype.toString
function isPlainObject(obj){
return _toString.call(obj)==='[object Object]'
}
function initMixin(){
Vue.prototype._init = function(options){
console.log('假装写了_init，以后补上')
}
}
function initExtend (Vue){
Vue.extend = function (){
const Super = this
const Sub = function Sub (options){
this._init(options)
}
Sub.prototype = Object.create(Super.prototype)
Sub.prototype.constructor = Sub
return Sub
}
}
// -----------------------------------------
function Vue(options){
this._init(options)
}
initMixin()
initExtend(Vue)
initAssetRegisters(Vue)
function initAssetRegisters(Vue){
// eg: Vue.component(id,{template:'#tem'}) ;Vue实例options里面的components:{Comp}
ASSET_TYPES.forEach(type=>{
Vue[type] = function (id,definition){
if(definition){
return this.options[type + 's'][id]
}else{
if(type==='component' && isPlainObject(definition)){
definition.name = definition.name || id
// 把组件配置转换为组件的构造函数
definition = Vue.extend(definition)
}
if(type === 'directive' && typeof definition === 'function'){
definition = {
bind:definition,
update:definition
}
}
// 全具注册，存储资源并赋值
// this.options['components']['Comp'] = definition
return definition
}
}
})
}
let vm = new Vue({
el:'#app',
components:{
Comp
}
})
console.log(Vue.extend)
console.log(Vue.component)
</script>
</html>