AJAX problem in IE (cache, maybe?)

[wpt394]

Hello everyone,

I have a little script that seems to hang up in internet explorer every now and again.

Basically, I have a php page that sets the following headers:

   header( "Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT" );
   header( "Cache-Control: post-check=1,pre-check=2" );
   header( "Cache-Control: no-cache, must-revalidate" );
   header( "Pragma: no-cache" );
   function setExpires($expires) {  
       header(  'Expires: '.gmdate('D, d M Y H:i:s', time()+$expires).'GMT');  
   }  
   setExpires(5);
 

Additionally, in this same page, there is a call to a javascript function using onload in the body tag.

That function starts one xmlhttprequest (which should take about 20 seconds or so to do), and also starts a second xmlhttprequest which continuously updates users with the status of the first request....

It looks something like this:

 
function startSearch(usersess)
{
    var url="/runsearch.php";
    url=url+"?usersess="+usersess;
    url=url+"&sid="+Math.random();
 
    searchRequest=GetXmlHttpObject();
    searchRequest.onreadystatechange=function(){
         searchReqChanged();
    }
    searchRequest.open("GET",url,true);
    searchRequest.send(null);
    getSorter(usersess);
}
 
function searchReqChanged(){
   if (searchRequest.readyState==4)
   {     
    repeatSort = 0;
   }
}
 
function getSorter(usersess)
{
    var usess= escape(encodeURI(usersess));
    var url="update.php";
    url=url+"?sid="+Math.random();
    url=url+"&usess="+usess;
    sorterRequest=GetXmlHttpObject();
                sorterRequest.onreadystatechange=function(){
           sorterReqChanged(usess);
    }
    sorterRequest.open("GET",url,true);
    sorterRequest.send(null);
}
 
function sorterReqChanged(usess){
   if (sorterRequest.readyState==4)
   { 
    document.getElementById("results").innerHTML=sorterRequest.responseText;
 
    if (repeatSort != -1){getSorter(usess);}
                if (repeatSort == 0){repeatSort = -1;}
   }
}
 

The problem is, in internet explorer, whenever I navigate to the page that starts up this function, sometimes it takes FOREVER to load. It is really strange, because when I take the no-cache headers off of the page, there is no problem. Regardless of the presence of the no-cache headers, it works fine in Mozilla.

I think it has to do with the AJAX because I've tried changing startSearc() to something like a simple alert and there are no troubles..

Any help would be much appreciated, as I've been stuck on this for quite awhile now...

Many thanks.

[wpt394]

Any ideas? I'm really having trouble with this one....

[acoder]

I'm not sure what might be causing the problem, but you could try making a unique request instead of setting cache headers. Use the Date object and append it to the url:

url+new Date().getTime();

Hope that helps.