Unexpected Caching of AJAX results in IE8

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 navigates to a new page. Once the page is loaded I do this

$.get("/game/getpuzzleinfo", null, function(data, status) {
    var content = "<h1>Wikipedia Maze</h1>";
    content += "<p class='endtopic'>Looking for <span><a title='Opens the topic you are looking for in a separate tab or window' href='" + data.EndTopicUrl + "' target='_blank'>" + data.EndTopic + "<a/></span></p>";
    content += "<p class='step'>Step <span>" + data.StepCount + "</span></p>";
    content += "<p class='level'>Level <span>" + data.PuzzleLevel.toString() + "</span></p>";
    content += "<p class='startover'><a href='/game/start/" + data.PuzzleId.toString() + "'>Start Over</a></p>";

    $("#wikiheader").append(content);

}, "json");

It just injects header info into the page. You can check it out by going to www.wikipediamaze.com and then logging in and starting a new puzzle.

In every browser I've tested (Google Chrome, Firefox, Safari, Internet Explorer) it works great except in IE. Eveything gets injected just fine in IE the first time but after that it never even makes the call to /game/getpuzzleinfo. It's like it has cached the results or something.

If I change the call to $.post("/game/getpuzzleinfo", ... IE picks it up just fine. But then Firefox quits working.

Can someone please shed some light on this as to why IE is caching my $.get ajax calls?

UPDATE

Per the suggestion below, I've changed my ajax request to this, which fixed my problem:

$.ajax({
    type: "GET",
    url: "/game/getpuzzleinfo",
    dataType: "json",
    cache: false,
    success: function(data) { ... }
});

IE is notorious for its aggressive caching of Ajax responses. As you're using jQuery, you can set a global option:

$.ajaxSetup({
    cache: false
});

which will cause jQuery to add a random value to the request query string, thereby preventing IE from caching the response.

Note that if you have other Ajax calls going on where you do want caching, this will disable it for those too. In that case, switch to using the $.ajax() method and enable that option explicitly for the necessary requests.

See http://docs.jquery.com/Ajax/jQuery.ajaxSetup for more info.

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
});

Unexpected Caching of AJAX results in IE8

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