Fluent Filters - Global Action Filters for ASP.NET MVC 2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;
using Microsoft.Practices.Unity;

namespace Website.Core
{
    public class UnityControllerFactory : DefaultControllerFactory
    {
        private readonly IUnityContainer _container;

        public UnityControllerFactory(IUnityContainer container)
        {
            _container = container;
        }

        protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
        {
            IController icontroller;

            if (controllerType == null)
            {
                throw new HttpException(404, String.Format("The controller for path '{0}' could not be found or it does not implement IController.",
                                        requestContext.HttpContext.Request.Path));
            }

            if (!typeof(IController).IsAssignableFrom(controllerType))
            {
                throw new ArgumentException(string.Format("Type requested is not a controller: {0}", controllerType.Name), "controllerType");
            }

            try
            {
                icontroller = _container.Resolve(controllerType) as IController; // Resolve controller
                var controller = icontroller as Controller;
                if (controller != null)
                {
                    // Set custom ActionInvoker
                    controller.ActionInvoker = _container.Resolve<IActionInvoker>();
                }
            }
            catch (Exception ex)
            {
                throw new InvalidOperationException(String.Format("Error resolving controller {0}", controllerType.Name), ex);
            }

            return icontroller;
        }
    }
}