How do I execute a controller action from an HttpModule in ASP.NET MVC?

Question

I've got the following IHttpModule and I'm trying to figure out how to execute an action from a controller for a given absolute or relative URL.

public class CustomErrorHandlingModule : IHttpModule
{
    #region Implementation of IHttpModule

    public void Init(HttpApplication context)
    {
        context.Error += (sender, e) => 
            OnError(new HttpContextWrapper(((HttpApplication)sender).Context));
    }

    public void Dispose()
    {}

    public void OnError(HttpContextBase context)
    {
        // Determine error resource to display, based on HttpStatus code, etc.
        // For brevity, i'll hardcode it for this SO question.
        const string errorPage = @"/Error/NotFound";

        // Now somehow execute the correct controller for that route.
        // Return the html response.
    }
}

How can this be done?

Answer 1

Something along the lines should do the job:

public void OnError(HttpContextBase context)
{
    context.ClearError();
    context.Response.StatusCode = 404;

    var rd = new RouteData();
    rd.Values["controller"] = "error";
    rd.Values["action"] = "notfound";
    IController controller = new ErrorController();
    var rc = new RequestContext(context, rd);
    controller.Execute(rc);
}

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