ivida

So IE9 is greedy when it comes to caching and automatically caches AJAX requests

This was an issue on an app that I’ve been working on that uses a lot of AJAX. IE9 was caching the AJAX requests and causing some problems downstream.

This can be stopped client side by setting cache to false in the JQuery ajaxSetup

$(document).ready(function() {
$.ajaxSetup({ cache: false });
});

However, I wanted to implement somthing server side, so that IE9 won’t cache any AJAX requests.

To do this I wrote an AjaxCacheControlAttribute that sniffs for AJAX requests and sets the relevant caching properites to prevent caching. To implement this across the app I then registered this in the GlobalFiltersCollection.

The attribute

public class AjaxCacheControlAttribute: ActionFilterAttribute
{
   public override void OnResultExecuted(ResultExecutedContext filterContext)
   {
       if (filterContext.RequestContext.HttpContext.Request.IsAjaxRequest())
       {
          filterContext.HttpContext.Response.Cache.SetExpires(DateTime.UtcNow.AddDays(-1));
          filterContext.HttpContext.Response.Cache.SetValidUntilExpires(false);
          filterContext.HttpContext.Response.Cache.SetCacheability(HttpCacheability.NoCache);
          filterContext.HttpContext.Response.Cache.SetNoStore();
       }
    }
}