xmlhttp.js

javascript实现的一个实时在线谈判模块



var XMLHttp = {
    _objPool: [],

    _getInstance: function ()
    {
        for (var i = 0; i < this._objPool.length; i ++)
        {
            if (this._objPool[i]["obj"].readyState == 0 ||(this._objPool[i]["obj"].readyState == 4&&this._objPool[i]["contentStage"]==1))
            {   
                this._objPool[i]["contentStage"]=0;
                return this._objPool[i];
            }
        }
//debugger;
        this._objPool[this._objPool.length]=new Array();
        this._objPool[this._objPool.length-1]["obj"]=this._createObj();
        this._objPool[this._objPool.length-1]["contentStage"]=0;
        return this._objPool[this._objPool.length - 1];
    },

    _createObj: function ()
    {
        if (window.XMLHttpRequest)
        {
            var objXMLHttp = new XMLHttpRequest();
            //XMLHttpRequest.contentStage=0;
        }
        else
        {
            var MSXML = ['MSXML2.XMLHTTP.5.0', 'MSXML2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP', 'Microsoft.XMLHTTP'];
            for(var n = 0; n < MSXML.length; n ++)
            {
            //debugger;
                try
                {  
                    
                    var objXMLHttp = new ActiveXObject(MSXML[n]);
                    //objXMLHttp.contentStage=0;
                    break;
                }
                catch(e)
                {
                }
            }
         }          


        if (objXMLHttp.readyState == null)
        {
            objXMLHttp.readyState = 0;

            objXMLHttp.addEventListener("load", function ()
                {
                    objXMLHttp.readyState = 4;

                    if (typeof objXMLHttp.onreadystatechange == "function")
                    {
                        objXMLHttp.onreadystatechange();
                    }
                },  false);
        }
        //debugger;
        //objXMLHttp.content="nihao";
        return objXMLHttp;
    },


    sendReq: function (method, url, data, callback)
    {
        var objXMLHttp = this._getInstance();

        with(objXMLHttp["obj"])
        {
            try
            {
           
                if (url.indexOf("?") > 0)
                {
                    url += "&randnum=" + Math.random();
                }
                else
                {
                    url += "?randnum=" + Math.random();
                }

                open(method, url, true);

       
                setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
                send(data);
                onreadystatechange = function ()
                {   if(objXMLHttp["obj"]){
                    if (objXMLHttp["obj"].readyState == 4 && (objXMLHttp["obj"].status == 200 || objXMLHttp["obj"].status == 304)&&callback!=null&&callback!="")
                    {
                        callback(objXMLHttp);
                        //callback();
                    }
                    }
                    else
                    {
     //***********************************duibaochu*****************************//
                        
                    }
                }
            }
            catch(e)
            {
                alert(e);
            }
        }
    }
};  

Array.prototype.remove=function(dx) 
  { 
    if(isNaN(dx)||dx>this.length){return false;} 
    for(var i=0,n=0;i<this.length;i++) 
    { 
        if(this[i]!=this[dx]) 
        { 
            this[n++]=this[i]; 
        }
        else
        {  
        //debugger;
         for(r in this[i])
              {
                this[i][r]=null;
              }     
            this[i]=null;
        } 
    } 
    this.length-=1 
  } 

var gar=function()
{
//debugger;
if (XMLHttp._objPool.length>1)
{
    for(i=XMLHttp._objPool.length-1;i>1;i--)
    {
            if(XMLHttp._objPool[i]["obj"].readyState == 0||(XMLHttp._objPool[i]["obj"].readyState == 4&&XMLHttp._objPool[i]["contentStage"]==1))
            {
                 // XMLHttp._objPool[i]["obj"].abort();            
                XMLHttp._objPool.remove(i);              
                //--i;
            }
    }
    CollectGarbage();
}
}
String.prototype.Trim = function() 
{ 
return this.replace(/(^\s*)|(\s*$)/g, ""); 
}