Overlapping routes with WebApi

Question

I'm trying to add a special route to the default WebApi sample:

The regular ones are

/api/values (retrieves all values)

/api/values/{id} (retrieves a specific value (by numeric id))

Now I want to add this api:

/api/values/special

The previous api (/api/values/{id}) should serve all requests with a numeric id, but /api/values/special should serve requests that call that specific url.

So far I got this for routing:

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

And this for implementation:

public class ValuesController : ApiController
{
    // GET api/values
    public IEnumerable<string> Get()
    {
        return new string[] { "value1", "value2" };
    }

    // GET api/values/5
    public string Get(int id)
    {
        return "value";
    }

    // POST api/values
    public void Post([FromBody]string value)
    {
    }

    // PUT api/values/5
    public void Put(int id, [FromBody]string value)
    {
    }

    // DELETE api/values/5
    public void Delete(int id)
    {
    }

    // GET api/values/special
    public IEnumerable<string> SpecialValues()
    {
        return new string[] { "special1", "special2" };
    }
}

But it will render: The requested resource does not support http method 'GET'.

If I call /api/values/special and I add [HttpGet] to the SpecialValues method it will work but /api/values will stop working saying that there are multiple matching actions.

siddharth · Accepted Answer · 2014-03-02T10:24:53.003

3

The changes to WebApiConfig is not needed. Attach a Route attribute and a HttpGet attribute. You can read more about it here.

[HttpGet]
[Route("api/{controller}/special")]
public IEnumerable<string> SpecialValues()
{
    return new string[] { "special1", "special2" };
}

WebApiConfig -

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Attribute routing.
        config.MapHttpAttributeRoutes();

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

edited Mar 02 '14 at 10:24

answered Mar 02 '14 at 00:22

siddharth

660
2
6
18

This results in the following message: The request is invalid. The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'System.String Get(Int32)' in 'MvcApplication1.Controllers.ValuesController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter. It is still picked up by the Get method – Fredrik Mar 02 '14 at 09:22
Your WebApiConfig class should be as updated in my answer. Also the url that you are invoking should be like - `http://hostname:port/api/values/special` – siddharth Mar 02 '14 at 10:26
1

Works like a charm, I had missed the part with MapHttpAttributeRoutes. Thanks! – Fredrik Mar 02 '14 at 12:47

score 0 · Answer 2 · edited May 23 '17 at 11:56

0

yes, as mentioned above, attribute based routing is the only way to go here...

this post may also interests you Overload web api action method based on parameter type

edited May 23 '17 at 11:56

Community

1
1

answered Mar 02 '14 at 05:52

Deepak Raj

730
2
9
26

This results in an error: Multiple actions were found that match the request: Get on type MvcApplication1.Controllers.ValuesController Get on type MvcApplication1.Controllers.ValuesController – Fredrik Mar 02 '14 at 09:24

Overlapping routes with WebApi

2 Answers2