原生JavaScript实现自定义弹窗组件

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>自定义弹窗</title>
  <link rel="stylesheet" href="alert.css" rel="external nofollow" >
</head>
<body>
   <button>Click me</button>
   <script src="index.js"></script>
   <script>
    document.querySelector("button").addEventListener("click",()=>{
     new $Msg({
      content:"我的自定义弹窗好了",
      type:"success",
      cancle:function(){
       let cancle = new $Msg({
        content:"我是取消后的回调"
       })
      },
      confirm:function(){
       new $Msg({content:"我是确定后的回调"})
      }
     })
    })
   </script>
</body>
</html>

/* 弹出框最外层 */
.msg__wrap {
  position: fixed;
  top: 50%;
  left: 50%;
  z-index: 10;
  transition: all .3s;
  transform: translate(-50%, -50%) scale(0, 0);
  max-width: 50%;
  background: #fff;
  box-shadow: 0 0 10px #eee;
  font-size: 10px;
 }
 /* 弹出框头部 */
 .msg__wrap .msg-header {
  padding: 10px 10px 0 10px;
  font-size: 1.8em;
 }
 .msg__wrap .msg-header .msg-header-close-button {
  float: right;
  cursor: pointer;
 }
 /* 弹出框中部 */
 .msg__wrap .msg-body {
  padding: 10px 10px 10px 10px;
  display: flex;
 }
 /* 图标 */
 .msg__wrap .msg-body .msg-body-icon{
  width: 80px;
 }
 .msg__wrap .msg-body .msg-body-icon div{
  width: 45px;
  height: 45px;
  margin: 0 auto;
  line-height: 45px;
  color: #fff;
  border-radius: 50% 50%;
  font-size: 2em;
 }
 .msg__wrap .msg-body .msg-body-icon .msg-body-icon-success{
  background: #32a323;
  text-align: center;
 }
 .msg__wrap .msg-body .msg-body-icon .msg-body-icon-success::after{
  content: "成";
 }
 .msg__wrap .msg-body .msg-body-icon .msg-body-icon-wrong{
  background: #ff8080;
  text-align: center;
 }
 .msg__wrap .msg-body .msg-body-icon .msg-body-icon-wrong::after{
  content: "误";
 }
 .msg__wrap .msg-body .msg-body-icon .msg-body-icon-info{
  background: #80b7ff;
  text-align: center;
 }
 .msg__wrap .msg-body .msg-body-icon .msg-body-icon-info::after{
  content: "注";
 }
 /* 内容 */
 .msg__wrap .msg-body .msg-body-content{
  min-width: 200px;
  font-size: 1.5em;
  word-break: break-all;
  display: flex;
  align-items: center;
  padding-left: 10px;
  box-sizing: border-box;
 }
 /* 弹出框底部 */
 .msg__wrap .msg-footer {
  padding: 0 10px 10px 10px;
  display: flex;
  flex-direction: row-reverse;
 }
 .msg__wrap .msg-footer .msg-footer-btn {
  width: 50px;
  height: 30px;
  border: 0 none;
  color: #fff;
  outline: none;
  font-size: 1em;
  border-radius: 2px;
  margin-left: 5px;
  cursor: pointer;
 }
 .msg__wrap .msg-footer .msg-footer-cancel-button{
  background-color: #ff3b3b;
 }
 .msg__wrap .msg-footer .msg-footer-cancel-button:active{
  background-color: #ff6f6f;
 }
 .msg__wrap .msg-footer .msg-footer-confirm-button{
  background-color: #4896f0;
 }
 .msg__wrap .msg-footer .msg-footer-confirm-button:active{
  background-color: #1d5fac;
 }
 /* 遮罩层 */
 .msg__overlay {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 5;
  background-color: rgba(0, 0, 0, .4);
  transition: all .3s;
  opacity: 0;
 }

/*
 *自定义弹窗
 */
//自执行函数 形成封闭的作用域 避免全局污染 
//传入windwo和document对象 相当于将window和document作为了作用域中的局部变量，
//就不需要内部函数沿着作用域链再查找到最顶层的window 提高运行效率。
(function (window, document) {
  //定义一个构造函数Msg 作为弹窗实例的构造函数。
  let Msg = function (options) {
    //执行初始化操作
    this._init(options);
  }
  //定义初始化方法 并对方法传递的参数进行初始化
  Msg.prototype = {
    _init({
      content = "", //文本内容
      type = "info", //信息类型
      useHTML = false, //是否解析html字符串
      showIcon = true, //是否展示弹窗图标
      confirm = null, //确认后得回调
      cancle = null, //取消后得回调
      footer = true, //是否显示底部的确认按钮
      header = true, //是否显示头部信息及关闭按钮
      title = "提示", //弹窗标题
      contentStyle = {}, //内容样式
      contentFontSize = "1.5em", //内容字体大小
      btnName = ["确定", "取消"] //按钮文字内容
    }) {
      //将传入的值绑定到this上 
      this.content = content;
      this.type = type;
      this.useHTML = useHTML;
      this.showIcon = showIcon;
      this.confirm = confirm;
      this.cancle = cancle;
      this.footer = footer;
      this.header = header;
      this.title = title;
      this.contentStyle = contentStyle;
      this.contentFontSize = contentFontSize;
      this.btnName = btnName;
      //执行创建元素方法
      this._creatElement();
      //显示弹窗及遮罩
      this._show({
        el: this._el,
        overlay: this._overlay
      });
      //绑定事件处理函数
      this._bind({
        el: this._el,
        overlay: this._overlay
      });
    },
    //创建弹窗元素方法
    _creatElement() {
      //创建最外层得包裹元素
      let wrap = document.createElement("div");
      wrap.className = "msg__wrap";
      //定义弹窗得两个按钮
      const [confirmBtnName, cancelBtnName] = this.btnName;
      //判断是否显示弹窗标题
      const headerHTML = this.header ?
        `<div class="msg-header">
            <span>${this.title}</span>
            <span class="msg-header-close-button">×</span>
          </div>` : "";
      //判断是否显示图标
      const iconHTML = this.showIcon ?
        `<div class="msg-body-icon">
          <div class="msg-body-icon-${this.type}"></div>
        </div>` : "";
      //判断是否显示弹窗底部按钮
      const footerHTML = this.footer ?
        `<div class="msg-footer">
            <button class="msg-footer-btn msg-footer-cancel-button">${cancelBtnName}</button>
            <button class="msg-footer-btn msg-footer-confirm-button">${confirmBtnName}</button>
          </div>` : "";
      //拼接完整html
      const innerHTML = `${headerHTML}
      <div class="msg-body">
        ${iconHTML}
        <div class="msg-body-content"></div>
      </div>
      ${footerHTML}`;
      //将拼接的html赋值到wrap中
      wrap.innerHTML = innerHTML;
      //把自定义的样式进行合并
      const contentStyle = {
        fontSize: this.contentFontSize,
        ...this.contentStyle
      }
      //获取内容所属DOM
      let content = wrap.querySelector(".msg-body .msg-body-content");
      //将传过来的样式添加到contentDOM
      for (const key in contentStyle) {
        if (contentStyle.hasOwnProperty(key)) {
          content.style[key] = contentStyle[key];
        }
      }
      //给弹窗的conntent赋值
      if (this.useHTML) {
        content.innerHTML = this.content;
      } else {
        content.innerText = this.content;
      }
      //创建遮罩层
      let overlay = document.createElement("div");
      overlay.className = "msg__overlay";
      //把dom挂载到当前实例上
      this._overlay = overlay;
      this._el = wrap;
    },
    //弹窗展现方法
    _show({
      el,
      overlay
    }) {
      //把弹窗的dom和遮罩插入到页面中
      document.body.appendChild(el);
      document.body.appendChild(overlay);
      //将弹窗显示出来 timeout进行异步处理显示动画
      setTimeout(() => {
        el.style.transform = "translate(-50%,-50%) scale(1,1)";
        overlay.style.opacity = "1";
      })
    },
    //关闭弹窗方法
    _close({
      el,
      overlay
    }) {
      //隐藏dom 
      el.style.transform = "translate(-50%,-50%) scale(0,0)";
      overlay.style.opcity = "0";
      //根据动画时间 动画完成再移除
      setTimeout(() => {
        //把弹窗的dom和遮罩移除
        document.body.removeChild(el)
        document.body.removeChild(overlay);
      }, 300);
    },
    //事件处理函数，为DOM绑定事件
    _bind({
      el,
      overlay
    }) {
      //保存当前this
      //const _this = this;
      const cancle = (e) => {
        this.cancle && this.cancle.call(this, e);
        //隐藏弹窗
        //hideMsg();
        this._close({
          el,
          overlay
        });
      }
      //确认弹窗
      const confirm = (e) => {
        this.confirm && this.confirm.call(this, e);
        this._close({
          el,
          overlay
        });
      }
      //顶部关闭按钮绑定事件
      if (this.header) {
        el.querySelector(".msg-header-close-button").addEventListener("click", cancle);
      }
      //弹窗底部两个按钮事件监听
      if (this.footer) {
        el.querySelector(".msg-footer-cancel-button").addEventListener("click", cancle);
        el.querySelector(".msg-footer-confirm-button").addEventListener("click", confirm)
      }
    }
  }
  //将构造函数暴露到window，这样才能在全局作用域下直接调用 
  window.$Msg = Msg;
})(window, document);