domReady

Posted 2020-09-21 叶常绿

new function(){
    dom = [];
    dom.isReady = false;
    dom.isFunction = function(obj){
        return Object.prototype.toString.call(obj) === "[object Function]";
    };
    dom.Ready = function(fn){
        dom.initReady();//如果没有建成DOM树，则走第二步，存储起来一起杀
        if(dom.isFunction(fn)){
            if(dom.isReady){
                fn();//如果已经建成DOM，则来一个杀一个
            }else{
                dom.push(fn);//存储加载事件
            }
        }
    };
    dom.fireReady =function(){
        if (dom.isReady)  return;
        dom.isReady = true;
        for(var i=0,n=dom.length;i<n;i++){
            var fn = dom[i];
            fn();
        }
        dom.length = 0;//清空事件
    };
    dom.initReady = function(){
        if (document.addEventListener) {
            document.addEventListener( "DOMContentLoaded", function(){
                document.removeEventListener( "DOMContentLoaded", arguments.callee, false );//清除加载函数
                dom.fireReady();
            }, false );
        }else{
            if (document.getElementById) {
                document.write ("<script id=\"ie-domReady\" defer=‘defer‘ src=\"//:\"><\/script>");
                document.getElementById("ie-domReady").onreadystatechange = function() {
                    if (this.readyState === "complete") {
                        dom.fireReady();
                        this.onreadystatechange = null;
                        this.parentNode.removeChild(this)
                    }
                };
            }
        }
    }
};