How do I handle an exception in an ASP.NET MVC controller factory

Question

I have an ASP.NET MVC 2 application with a custom StructureMap controller factory to handle dependency injection for my controllers:

public class StructureMapControllerFactory : DefaultControllerFactory
{
    public override IController CreateController(RequestContext context, string controllerName)
    {
        Type controllerType = base.GetControllerType(context, controllerName);
        return ObjectFactory.GetInstance(controllerType) as IController;
    }
}

I would like to know how I can handle exceptions in this controller factory so that they can be redirected to the ~/Views/Shared/Error.aspx in the same way as they are in a controller that has the HandleError attribute. Currently exceptions don't do this despite having the CustomErrors attribute set to "On".

At the moment I can generate such an exception using a URL like "~/DoesNotExist/edit/1". With the default route:

routes.MapRoute(
    "Default", // Route name
    "{controller}/{action}/{id}", // URL with parameters
    new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);

MVC matches this route and passes controller name "DoesNotExist" to my controller factory. The GetControllerType then returns null and causes a null reference exception in the call to StructureMap. I would then like to be able to handle this exception.

Note that adding a subsequent catch all route will not resolve this problem - MVC matches the default route.

I know I could solve this particular problem by putting constraints on the default route for controller but the question is more general about how I can use the normal MVC ~/Views/Shared/Error.aspx in the factory.

Note that I don't want the answer to require tight coupling of the controller factory to the particular MVC application. Ideally this factory should be in a referenced assembly not in the same solution.

Answer 1

Maybe you can adapt this controller factory to handle the exceptions.