Question

I have a web project with two models – IndicatorModel and GranteeModel. I also have corresponding ApiControllers for each – IndicatorsController, and GranteesController. I’m planning on using this setup for a data API alongside my actual web project, so I’ve created a new Area in my project named simply “Api”. In my ApiAreaRegistration class, I’m registering routes for these controllers like this:

context.Routes.MapHttpRoute(
  name: "ApiDefault",
  routeTemplate: "api/{controller}/{id}",
  defaults: new { id = RouteParameter.Optional }
);

Basically, a request to http://myapp/api/indicators/123 should go to the Indicators controller, and it should specifically be handled by an action method that accepts an integer parameter. My controller class is setup as follows, and it works perfectly:

public class IndicatorsController : ApiController
{
    // get: /api/indicators/{id}
    public IndicatorModel Get(int id)
    {
        Indicator indicator = ...// find indicator by id
        if (indicator == null)
        {
            throw new HttpResponseException(HttpStatusCode.NotFound);
        }
        return new IndicatorModel(indicator);
    }
}

My GranteesController class is setup identically:

public class GranteesController : ApiController
{
    // get: /api/grantees/{id}
    public GranteeModel Get(int granteeId)
    {
        Grantee grantee = ... // find grantee by Id
        if (grantee == null)
        {
            throw new HttpResponseException(HttpStatusCode.NotFound);
        }
        return new GranteeModel(grantee);
    }
}

Now the problem – if I try a request to http://myapp/api/grantees/123, I get a 404 and I’m 100% positive that the 404 is not coming from my Get method. For one, I’ve tried debugging and logging within that method, and the method is never actually hit. Also, the actual output (json) to the request looks like this:

{ 
  "Message": "No HTTP resource was found that matches the request URI 'http://myapp/api/grantees/25'.",
  "MessageDetail": "No action was found on the controller 'Grantees' that matches the request."
}

Also, the output to my TraceWriter log looks like this:

;;http://myapp/api/grantees/10
DefaultHttpControllerSelector;SelectController;Route='controller:grantees,id:10'
DefaultHttpControllerSelector;SelectController;Grantees
HttpControllerDescriptor;CreateController;
DefaultHttpControllerActivator;Create;
DefaultHttpControllerActivator;Create;MyApp.Areas.Api.Controllers.GranteesController
HttpControllerDescriptor;CreateController;MyApp.Areas.Api.Controllers.GranteesController
GranteesController;ExecuteAsync;
ApiControllerActionSelector;SelectAction;
DefaultContentNegotiator;Negotiate;Type='HttpError', formatters=[JsonMediaTypeFormatterTracer...

So my request is getting routed correctly – the correct controller is selected, and the Id property is set correctly (10). However, the ApiControllerActionSelector isn’t finding a method on the controller which matches. I’ve also tried adding in the [HttpGet] attribute to my Get methods, with no success.

Does anyone have any ideas of what might be happening here? I cannot for the life of me figure out why the action selector isn’t finding the correct action.

Answer 1

The parameter name on GranteesController’s action need to be modified from ‘granteeId’ to ‘id’:

public GranteeModel Get(int id)