<!DOCTYPE html>
<html lang="zh-CN">
<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>Document</title>
<style>
#loginlayer {
width: 100px;
height: 100px;
background-color: yellow;
}
</style>
</head>
<body>
<button id="loginBtn">点击登录</button>
<button id="iframeBtn">iframe</button>
<script>
// 用代理实现单例模式
/* let CreatedDiv = function(html) {
this.html = html
this.init()
}
CreatedDiv.prototype.init = function() {
let div = document.createElement("div")
div.innerHTML = this.html
document.body.appendChild(div)
}
let ProxyCreatedDiv = (function() {
let instance
return function(html) {
if(!instance) {
instance = new CreatedDiv(html)
}
return instance
}
})()
let a = new ProxyCreatedDiv('div1')
let b = new ProxyCreatedDiv('div2')
console.log(a === b) */
// 通用的惰性单例模式
let createdLoginlayer = function() {
let div = document.createElement("div")
div.id = "loginlayer"
div.innerHTML = "我是登录浮窗"
div.style.display = "none"
document.body.appendChild(div)
return div
}
let createdIframe = function() {
let idframe = document.createElement("iframe")
document.body.appendChild(idframe)
return idframe
}
// 管理单例逻辑
let getSingle = function(fn){
var instance
return function(){
return instance ?? (instance = fn.apply(this, arguments))
}
}
let createdSingleLoginlayer = getSingle(createdLoginlayer)
document.getElementById('loginBtn').onclick = function() {
createdSingleLoginlayer().style.display = "block"
}
let createddSingleIframe = getSingle(createdIframe)
document.getElementById('iframeBtn').onclick = function() {
createddSingleIframe().src = "https://www.baidu.com"
}
</script>
</body>
</html>
