Since the ultimate goal of creating the catchall route was to be able to handle dynamic urls and I was unable to find a direct answer to the original issue above, I approached my research from a different perspective. In doing so I came across this blog post: Custom 404 when no route matches
This solution allows handling of multiple sections within a given url (i.e. www.mysite.com/this/is/a/dynamic/route)
Here is the final custom controller code:
public override IController CreateController(System.Web.Routing.RequestContext requestContext, string controllerName)
{
if (requestContext == null)
{
throw new ArgumentNullException("requestContext");
}
if (String.IsNullOrEmpty(controllerName))
{
throw new ArgumentException("MissingControllerName");
}
var controllerType = GetControllerType(requestContext, controllerName);
// This is where a 404 is normally returned
// Replaced with route to catchall controller
if (controllerType == null)
{
// Build the dynamic route variable with all segments
var dynamicRoute = string.Join("/", requestContext.RouteData.Values.Values);
// Route to the Catchall controller
controllerName = "CatchAll";
controllerType = GetControllerType(requestContext, controllerName);
requestContext.RouteData.Values["Controller"] = controllerName;
requestContext.RouteData.Values["action"] = "ChoosePage";
requestContext.RouteData.Values["dynamicRoute"] = dynamicRoute;
}
IController controller = GetControllerInstance(requestContext, controllerType);
return controller;
}