Ajax
本人初次接触ajax,大家帮帮忙看下面的代码具体是什么意思,只能看懂创建XMLHttpRequest对象这部分。急啊,谢谢喽
我的分数就这么多,都给了
var net=new Object();
net.AjaxRequest=function(url,onload,onerror,method,params){
this.req=null;
this.onload=onload;
this.onerror=(onerror) ? onerror : this.defaultError;
this.loadDate(url,method,params);
}
net.AjaxRequest.prototype.loadDate=function(url,method,params){
if (!method){
method="GET";
}
if (window.XMLHttpRequest){//创建XMLHttpRequest对象
this.req=new XMLHttpRequest();
} else if (window.ActiveXObject){
this.req=new ActiveXObject("Microsoft.XMLHTTP");
}
if (this.req){
try{
var loader=this;
this.req.onreadystatechange=function(){
net.AjaxRequest.onReadyState.call(loader);
}
this.req.open(method,url,true);
this.req.send(null);
}catch (err){
this.onerror.call(this);
}
}
}
net.AjaxRequest.onReadyState=function(){ //重构onReadyState函数
var req=this.req;
var ready=req.readyState;
if (ready==4){
if (req.status==200 ){
this.onload.call(this);
}else{
this.onerror.call(this);
}
}
net.AjaxRequest.prototype.defaultError=function(){ //默认的错误处理函数
alert("error fetching data!"
+"\n\nreadyState:"+this.req.readyState
+"\nstatus: "+this.req.status
+"\nheaders: "+this.req.getAllResponseHeaders());
}
}