Unexpected Caching of AJAX results in IE8

Question

I\'m having a serious issue with Internet Explorer caching results from a JQuery Ajax request.

I have header on my web page that gets updated every time a user navig

Answer 1

this is what i do for ajax calls:

var url = "/mypage.aspx";
// my other vars i want to add go here
url = url + "&sid=" + Math.random();
// make ajax call

it works pretty well for me.

Answer 2

Just wrote a blog on this exact issue only using ExtJS (http://thecodeabode.blogspot.com/2010/10/cache-busting-ajax-requests-in-ie.html )

The problem was as I was using a specific url rewriting format I couldn't use conventional query string params (?param=value), so I had write the cache busting parameter as a posted variable instead..... I would have thought that using POST variables are a bit safer that GET, simply because a lot of MVC frameworks use the pattern

protocol://host/controller/action/param1/param2

and so the mapping of variable name to value is lost, and params are simply stacked... so when using a GET cache buster parameter

i.e. protocol://host/controller/action/param1/param2/no_cache122300201

no_cache122300201 can be mistaken for a $param3 parameter which could have a default value

i.e.

public function action($param1, $param2, $param3 = "default value") { //..// }

no chance of that happening with POSTED cache busters

Answer 3

As marr75 mentioned, GET's are cached.

There are a couple of ways to combat this. Aside from modifying the response header, you can also append a randomly generated query string variable to the end of the targeted URL. This way, IE will think it is a different URL each time it is requested.

There are multiple ways to do this (such as using Math.random(), a variation on the date, etc).

Here's one way you can do it:

var oDate = new Date();
var sURL = "/game/getpuzzleinfo?randomSeed=" + oDate.getMilliseconds();
$.get(sURL, null, function(data, status) {
    // your work
});

Answer 4

If you are calling ashx page you can also disable caching on the server with the following code:

context.Response.Cache.SetCacheability(HttpCacheability.NoCache);
context.Response.Cache.SetRevalidation(HttpCacheRevalidation.AllCaches); 

Answer 5

NickFitz gives a good answer, but you'll need to turn the caching off in IE9 as well. In order to target just IE8 and IE9 you could do this;

<!--[if lte IE 9]>
<script>
    $.ajaxSetup({
        cache: false
    });
</script>
<![endif]-->

Answer 6

The answers here are very helpful for those who use jQuery or for some reason directly use the xmlHttpRequest object...

If you're using the auto-generated Microsoft service proxy its not as simple to solve.

The trick is to use Sys.Net.WebRequestManager.add_invokingRequest method in the event handler change the request url:

networkRequestEventArgs._webRequest._url = networkRequestEventArgs._webRequest._url + '&nocache=' + new Date().getMilliseconds(); 

I've blogged about this: http://yoavniran.wordpress.com/2010/04/27/ie-caching-ajax-results-how-to-fix/