WebApi's custom exception when "does not support http method"

Question

I have a simple controller :

   public class UsersController : ApiController
    {
        [HttpPost]
        [AllowAnonymous]
         public HttpResponseMessage Login([FromBody] UserLogin userLogin)
         {
             var userId = UserCleaner.Login(userLogin.MasterEntity, userLogin.UserName, userLogin.Password, userLogin.Ua);
             if (userId == null) return Request.CreateErrorResponse(HttpStatusCode.Unauthorized, "User not authorized");
             return Request.CreateResponse(HttpStatusCode.OK, Functions.RequestSet(userId)); 

         }
   }

As you can see , only POST is currently available .

But when I invoke a GET in a browser (just for checking):

http://royipc.com:88/api/users

I get :

{"Message":"The requested resource does not support http method 'GET'."}

It is clear to me why it happens. But I want to return a custom exception when it happens.

Other answers here at SO doesn't show how I can treat this kind of situation (not that i've found of, anyway)

Question

How (and where) should I catch this kind of situation and return custom exception (HttpResponseMessage) ?

NB

I don't want to add a dummy GET method just for "catch and throw". tomorrow there can be a GET method. I just want to catch this Exception and return my OWN !

Answer 1

You may need to inherit from ApiControllerActionSelector class which is what the Web API uses to select the required action.

then you can replace the default IHttpActionSelector by your new action selector like that. config.Services.Replace(typeof(IHttpActionSelector), new MyActionSelector());

check this url for full example: http://www.strathweb.com/2013/01/magical-web-api-action-selector-http-verb-and-action-name-dispatching-in-a-single-controller/