How to invalidate cache data [OutputCache] from a Controller?

Question

Using ASP.Net MVC 3 I have a Controller which output is being cached using attributes [OutputCache]

[OutputCache]
public controllerA(){}

I would like to know if it is possible to invalidate the Cache Data (SERVER CACHE) for a Specific Controller or generally all the Cache data by calling another controller

public controllerB(){} // Calling this invalidates the cache

Answer 1

You could use the RemoveOutputCacheItem method.

Here's an example of how you could use it:

public class HomeController : Controller
{
    [OutputCache(Duration = 60, Location = OutputCacheLocation.Server)]
    public ActionResult Index()
    {
        return Content(DateTime.Now.ToLongTimeString());
    }

    public ActionResult InvalidateCacheForIndexAction()
    {
        string path = Url.Action("index");
        Response.RemoveOutputCacheItem(path);
        return Content("cache invalidated, you could now go back to the index action");
    }
}

The Index action response is cached on the server for 1 minute. If you hit the InvalidateCacheForIndexAction action it will expire the cache for the Index action. Currently there's no way to invalidate the entire cache, you should do it per cached action (not controller) because the RemoveOutputCacheItem method expects the url of the server side script that it cached.

Answer 2

You can do that by using a custom attribute, like so:

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
public sealed class NoCacheAttribute : ActionFilterAttribute
{
    public override void OnResultExecuting(ResultExecutingContext filterContext)
    {
        filterContext.HttpContext.Response.Cache.SetExpires(DateTime.UtcNow.AddDays(-1));
        filterContext.HttpContext.Response.Cache.SetValidUntilExpires(false);
        filterContext.HttpContext.Response.Cache.SetRevalidation(HttpCacheRevalidation.AllCaches);
        filterContext.HttpContext.Response.Cache.SetCacheability(HttpCacheability.NoCache);
        filterContext.HttpContext.Response.Cache.SetNoStore();

        base.OnResultExecuting(filterContext);
    }
}

Then on your controllerb you can do:

[NoCache]
public class controllerB
{
}