Question

I’m working on my first ASP.NET MVC 3 application and I’ve got a couple of actions defined to handle adding/removing an ice cream from a menu. They look like so:

[HttpPost]
public PartialViewResult AddMenuIceCreamMapping(int iceCreamId, int menuId)


[HttpPost]
public PartialViewResult RemoveMenuIceCreamMapping(int iceCreamId, int menuId)

In order for these actions to not result in a 404 error, I went into the Global.asax.cs file and added the following:

routes.MapRoute(
  "AddMenuIceCreamMapping", // Route name
  "IceCream/AddMenuIceCreamMapping/{iceCreamId}/{menuId}", // URLwith parameters
  new
  {
     controller = "IceCream",
     action = "AddMenuIceCreamMapping",
     iceCreamId = UrlParameter.Optional,
     menuId = UrlParameter.Optional
  } 
);

routes.MapRoute(
  "RemoveMenuIceCreamMapping", // Route name
  "IceCream/RemoveMenuIceCreamMapping/{iceCreamId}/{menuId}", // URLwith parameters
  new
  {
     controller = "IceCream",
     action = "RemoveMenuIceCreamMapping",
     iceCreamId = UrlParameter.Optional,
     menuId = UrlParameter.Optional
  } 
);

and those work, meaning I can click an Add or Remove button on my page and add or remove an ice cream/menu mapping. Great. But I’m expecting that there will be more situations like this and I can see this routes container having more entries such as these. And to my novice web programmer eye, it seems a bit clunky and I begin to think that perhaps I’m going about this the wrong way. Am I? Is there a better way to approach this so that I don’t end up doing the “go create some action that takes N parameters and then go add a route” thing. Any suggestions here?

Answer 1

You can use placeholders in your mappings to deal with this… Instead of what you’ve got above, you could use this (note that I don’t specify a default):

routes.MapRoute(
                "TwoParameterRoute", // Route name
                "{controller}/{action}/{id1}/{id2}", // URL with parameters
               );

And if you have to add a route that takes three parameters, you extend the idea:

routes.MapRoute(
                "ThreeParameterRoute", // Route name
                "{controller}/{action}/{id1}/{id2}/{id3}" // URL with parameters
               );

In a controller for the two parameter route, the code would look like this (for a contrived sample):

public ActionResult Index(int id1, int id2)
    {
        ViewData["id1"] = id1;
        ViewData["id2"] = id2;

        return View();
    }

One final thing to note is that you can change the naming to match a pattern you might have. In the first example, instead of id1 and id2 you might have entityId and relatedId or something similar.