Multiple HttpPost method in Web API controller

Question

I am starting to use MVC4 Web API project, I have controller with multiple HttpPost methods. The Controller looks like the following:

Controller

public class VTRoutingController : ApiController
{
    [HttpPost]
    public MyResult Route(MyRequestTemplate routingRequestTemplate)
    {
        return null;
    }

    [HttpPost]
    public MyResult TSPRoute(MyRequestTemplate routingRequestTemplate)
    {
        return null;
    }
}

Here MyRequestTemplate represents the template class responsible for handling the Json coming through the request.

Error:

When I make a request using Fiddler for http://localhost:52370/api/VTRouting/TSPRoute or http://localhost:52370/api/VTRouting/Route I get an error:

Multiple actions were found that match the request

If I remove one of the above method it works fine.

Global.asax

I have tried modifying the default routing table in global.asax, but I am still getting the error, I think I have problem in defining routes in global.asax. Here is what I am doing in global.asax.

public static void RegisterRoutes(RouteCollection routes)
{
    routes.MapHttpRoute(
        name: "MyTSPRoute",
        routeTemplate: "api/VTRouting/TSPRoute",
        defaults: new { }
    );

    routes.MapHttpRoute(
        name: "MyRoute",
        routeTemplate: "api/VTRouting/Route",
        defaults: new { action="Route" }
    );
}

I am making the request in Fiddler using POST, passing json in RequestBody for MyRequestTemplate.

Answer 1

I just added "action=action_name" to the url and this way the routing engine knows what action I want. I also added the ActionName Attribute to the actions but I'm not sure it's needed.

Answer 2

use:

routes.MapHttpRoute(
    name: "DefaultApi",
    routeTemplate: "api/{controller}/{action}/{id}",
    defaults: new { id = RouteParameter.Optional }
);

it's not a RESTful approach anymore, but you can now call your actions by name (rather than let the Web API automatically determine one for you based on the verb) like this:

[POST] /api/VTRouting/TSPRoute

[POST] /api/VTRouting/Route

Contrary to popular belief, there is nothing wrong with this approach, and it's not abusing Web API. You can still leverage on all the awesome features of Web API (delegating handlers, content negotiation, mediatypeformatters and so on) - you just ditch the RESTful approach.

Answer 3

public class Journal : ApiController
{
    public MyResult Get(journal id)
    {
        return null;
    }
}

public class Journal : ApiController
{

    public MyResult Get(journal id, publication id)
    {
        return null;
    }
}

I am not sure whether overloading get/post method violates the concept of restfull api,but it workds. If anyone could've enlighten on this matter. What if I have a uri as

uri:/api/journal/journalid
uri:/api/journal/journalid/publicationid

so as you might seen my journal sort of aggregateroot, though i can define another controller for publication solely and pass id number of publication in my url however this gives much more sense. since my publication would not exist without journal itself.

Answer 4

I think the question has already been answered. I was also looking for something a webApi controller that has same signatured mehtods but different names. I was trying to implement the Calculator as WebApi. Calculator has 4 methods with the same signature but different names.

public class CalculatorController : ApiController
{
    [HttpGet]
    [ActionName("Add")]
    public string Add(int num1 = 1, int num2 = 1, int timeDelay = 1)
    {
        Thread.Sleep(1000 * timeDelay);
        return string.Format("Add = {0}", num1 + num2);
    }

    [HttpGet]
    [ActionName("Sub")]
    public string Sub(int num1 = 1, int num2 = 1, int timeDelay = 1)
    {
        Thread.Sleep(1000 * timeDelay);
        return string.Format("Subtract result = {0}", num1 - num2);
    }

    [HttpGet]
    [ActionName("Mul")]
    public string Mul(int num1 = 1, int num2 = 1, int timeDelay = 1)
    {
        Thread.Sleep(1000 * timeDelay);
        return string.Format("Multiplication result = {0}", num1 * num2);
    }

    [HttpGet]
    [ActionName("Div")]
    public string Div(int num1 = 1, int num2 = 1, int timeDelay = 1)
    {
        Thread.Sleep(1000 * timeDelay);
        return string.Format("Division result = {0}", num1 / num2);
    }
}

and in the WebApiConfig file you already have

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

Just set the authentication / authorisation on IIS and you are done!

Hope this helps!

Answer 5

A much better solution to your problem would be to use Route which lets you specify the route on the method by annotation:

[RoutePrefix("api/VTRouting")]
public class VTRoutingController : ApiController
{
    [HttpPost]
    [Route("Route")]
    public MyResult Route(MyRequestTemplate routingRequestTemplate)
    {
        return null;
    }

    [HttpPost]
    [Route("TSPRoute")]
    public MyResult TSPRoute(MyRequestTemplate routingRequestTemplate)
    {
        return null;
    }
}

Answer 6

It is Possible to add Multiple Get and Post methods in the same Web API Controller. Here default Route is Causing the Issue. Web API checks for Matching Route from Top to Bottom and Hence Your Default Route Matches for all Requests. As per default route only one Get and Post Method is possible in one controller. Either place the following code on top or Comment Out/Delete Default Route

    config.Routes.MapHttpRoute("API Default", 
                               "api/{controller}/{action}/{id}",
                               new { id = RouteParameter.Optional });