MVC route constraint custom attribute - asp.net-mvc

Question

I'd like to setup a custom route constraint that would allow me to decorate a controller with an attribute so that I don't have to pass in string to the route and remember to update it with new controller names.
I thought I could setup use the IRouteConstraint but I can't seem to get the attribute. Perhaps I'm just missing something obvious here.
routes.MapRoute("test",
"foo/{controller}/{action}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional },
new { controller = new TestConstraint()}
);
routes.MapRoute("Default", "{controller}/{action}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);
public class TestConstraint : IRouteConstraint
{
public bool Match(HttpContextBase httpContext, Route route, string parameterName,
RouteValueDictionary values,
RouteDirection routeDirection)
{
return false;
}
}
[AttributeUsage(AttributeTargets.Class)]
public class CustomConstraintControllerAttribute : Attribute
{
}
[CustomConstraintController]
public class TestController : Controller
{
public ActionResult Index()
{
return View();
}
}
Edit:
Current Method:
routes.MapSubdomainRoute("Store",
"{store}/{controller}/{action}/{id}",
new {controller = "Home", action = "Index", id = UrlParameter.Optional},
new {controller = "StoreHome|Contacts|..." }
);
This route configuration ensures that a url must match subdomain.test.com/GiggleInc/Contacts or subdomain.test.com/GiggleInc/StoreHome.
subdomain.test.com/GiggleInc/StoreHome
MapSubdomainRoute /{store} /{controller}/{action}/{id}
This method requires that each controller that should be used this way must be added to the controller constraint.
As I mentioned in the comments, I want to replace the hard coded strings for an attribute or something similar.

Answer 1

First, thank you for this sweet line of code I didn't know was possible:
constraints: new { controller = "StoreHome|Contacts" }
I didn't know I could filter my MapRoute to a list of Controllers so easily.
Second, you don't need to implement a custom IRouteConstraint for this.
MVC offers the Attribute-Routing you are looking for.
You may even include Default/Optional Values, just like in your MapRoute.
Decorate your Controller Class like so:
[RoutePrefix("{store}/Test")]
[Route("{action=Index}/{id?}")]//Without this, you need to define "[Route]" above every Action-Method.
public class TestController : Controller
{
public ActionResult Index(string store)//Adding "string store" is optional.
{
return View();
}
}
That's it.
Remember to add the "store" Parameter in all your Actions under each Controller (but it is not Required).
Note:
If you use Attributes instead of MapRoute, then you will not be able to hit the Controller without the "store" Prefix.
With the Custom and Default MapRoutes, you could have accessed your controller either way.
By decorating your Controller with these Attributes, you now force it to only use this exact path.
This may be what you want, but if you start IIS Express from Visual Studio on one of your Views, it will not find it, because Visual Studio doesn't know to add the RoutePrefix for you.
See this link for more information about Attribute-Routing:
https://blogs.msdn.microsoft.com/webdev/2013/10/17/attribute-routing-in-asp-net-mvc-5/

Answer 2

Try this...
public class TestRouteAttribute : RouteFactoryAttribute
{
public TestRouteAttribute(string template) : base(template) { }
public override RouteValueDictionary Constraints
{
get
{
var constraints = new RouteValueDictionary();
constraints.Add("TestConstraint", new TestConstraint());
return constraints;
}
}
}
Then you should be able to decorate your action methods using [TestRoute]
By the way, would love to know how to accomplish this in asp.net core if anyone knows.