AJAX as an object

[jnutty1]

Hi,I have a problem with creating an AJAX object. I took the code that is in the AJAX section of this site and it worked just fine. But, if I create an object of the same code (see below) the onreadystatechange function doesn't seem to recognize elements in the object.

function sendData(smethod,surl,sdata,basync,index){  this.GetXmlHttpObject=GetXmlHttpObject;  this.index=index;  this.xmlHttp=this.GetXmlHttpObject()  if (this.xmlHttp==null)  {	alert ("Browser does not support HTTP Request")  }   if (smethod.toUpperCase()=="GET" && sdata.length>0){	 surl+="?"+sdata;	 sdata=null;  }  this.xmlHttp.onreadystatechange=function(){   if (this.xmlHttp.readyState==4 || this.xmlHttp.readyState=="complete")  {      doResponse(this.xmlHttp.responseText,this.index);  } } this.xmlHttp.open(smethod,surl,basync);this.xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");this.xmlHttp.send(sdata);} function GetXmlHttpObject(){ var xmlHttp=null;  try	{	// Firefox, Opera 8.0+, Safari		xmlHttp=new XMLHttpRequest();	}  catch (e)	{	// Internet Explorer	  try		{		   xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");		}	  catch (e)		{		   try			 {			   xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");			 }		   catch (e)			 {			   //alert("Your browser does not support AJAX!");			 }		}	}return xmlHttp;}

The javascript code to create the objects would be as follows:

var aj=new Array();function test(){   aj[0]=new sendData('POST','pagea.php','id=1',true,0)   aj[1]=new sendData('POST','pageb.php','id=2',true,1)}function doResponse(s,index){  do something with s.  aj[index]=null;}

Each time a sendData object is created and the onreadystatechange function executes, an error stating that this.xmlHttp.readyState is null or not an object (in IE) or it doesn't have any properties (in netscape, firefox).Any thought would be appreciated.

[jesh]

The way I handled this was to use a private variable (without the this keyword) to store my httpRequest object inside my AJAX object and I used an internal function to handle the readystatechange event (to which I could pass a reference to a separate function to handle the response):

function sendData(smethod,surl,sdata,basync,index,callback){  this.GetXmlHttpObject=GetXmlHttpObject;  this.index=index;  var xmlHttp=this.GetXmlHttpObject()  ...  xmlHttp.onreadystatechange=function(){ HandleAjaxRequest(callback); }  function HandleAjaxRequest(callback)  {	if(xmlHttp.readyState == 4)	{		callback(xmlHttp);	}  }  ...}

Then, you could use it like this:

function myCallbackHandler(response){	alert(response.responseText);}var test = new sendData('POST','pagea.php','id=1',true,0,myCallbackHandler);

Hope it helps!