原生JavaScript弹出层插件开发：架构设计与参数配置

;(function(window,document){
 var MaskShare = function(){
 };
 MaskShare.prototype = {};
 window.MaskShare = MaskShare;
}(window,document));

;(function(window,document){
 var MaskShare = function(targetDom,options){
  // 判断是用函数创建的还是用new创建的。这样我们就可以通过MaskShare("dom") 或 new MaskShare("dom")来使用这个插件了
  if(!(this instanceof MaskShare))return new MaskShare(targetDom,options);
  // 参数合并
  this.options = this.extend({
      // 这个参数以后可能会更改所以暴露出去
   imgSrc:"../static/img/coupon-mask_1.png"
  },options);
  // 判断传进来的是DOM还是字符串
  if((typeof targetDom)==="string"){
   this.targetDom = document.querySelector(targetDom);
  }else{
   this.targetDom = targetDom;
  }
  var boxDom = document.createElement("div");
  var imgDom = document.createElement("img");
  // 设置默认样式 注意将z-index值设置大一些，防止其他元素层级比遮罩层高
  boxDom.style.cssText = "display: none;position: absolute;left: 0;top: 0;width: 100%;height:100%;background-color: rgba(0,0,0,0.8);z-index:9999;";
  imgDom.style.cssText = "margin-top:20px;width: 100%;";
  // 追加或重设其样式
  if(this.options.boxDomStyle){
   this.setStyle(boxDom,this.options.boxDomStyle);
  }
  if(this.options.imgDomStyle){
   this.setStyle(imgDom,this.options.imgDomStyle);
  }
  imgDom.src = this.options.imgSrc;
  boxDom.appendChild(imgDom);
  this.boxDom = boxDom;
  // 初始化
  this.init();
 };
 MaskShare.prototype = {
  init:function(){
   this.event();
  },
  extend:function(obj,obj2){
   for(var k in obj2){
    obj[k] = obj2[k];
   }
   return obj;
  },
  setStyle:function(dom,objStyle){
   for(var k in objStyle){
    dom.style[k] = objStyle[k];
   }
  },
  event:function(){
   var _this = this;
   this.targetDom.addEventListener("click",function(){
    document.body.appendChild(_this.boxDom);
    _this.boxDom.style.display = "block";
        // 打开遮罩层的回调
    _this.options.open&&_this.options.open();
   },false);
   this.boxDom.addEventListener("click",function(){
    this.style.display = "none";
        // 关闭遮罩层的回调
    _this.options.close&&_this.options.close();
   },false);
  }
 };
 // 暴露方法
 window.MaskShare = MaskShare;
}(window,document));

MaskShare(".immediately",{
 imgSrc:"../static/img/loading_icon.gif",
 boxDomStyle:{
  opacity:".9"
 },
 imgDomStyle:{
  opacity:".8"
 },
 open:function(){
  console.log("show");
 },
 close:function(){
  console.log("close");
 }
});