WebApi route identifying several controller types that match the same URL. How to solve?

Question

I have:

[RoutePrefix("api/Order")]
public class OrderController : ApiController
{
    [Route("~/api/Order/{id}")]
    [Route("~/api/ManualOrder/{id}")]
    [HttpGet]
    public Task<HttpResponseMessage> Get(Guid id)
    {
        //Implementation
    }

    [Route("ExampleOtherNormalMethod")]
    [HttpGet]
    public Task<HttpResponseMessage> ExampleOtherNormalMethod()
    {
        //Implementation
    }
}

And:

[RoutePrefix("api/ManualOrder")]
public class ManualOrderController : ApiController
{
    //Other methods
}

The strategy used by route rewriting is to get the "Get" method called either "/api/Order/1" or "/api/ManualOrder/1" both pointing to "OrderController", this works.

The problem is when I request any other method in the "ManualOrder" I think it gets lost and can not resolve and returns the exception:

Multiple controller types were found that match the URL. This can happen if attribute routes on multiple controllers match the requested URL. The request has found the following matching controller types: Project.ProxyAPI.Controllers.ManualOrderController Projects.ProxyAPI.Controllers.OrderController

Does anyone know how to solve this without duplicating the "Get" method on both controllers?

P.s: This is a hypothetical example.

Answer 1

I'm sure your example is much more complex than the one you present here. But based on the information in your example you could let ManualOrderController inherit from OrderController. I think it makes more sense when you assign the routes. The Route-attributes will not be inherited, so it shouldn't be any problem.

Does anyone know how to solve this without duplicating the "Get" method on both controllers?

Yes, it will be a duplicate, but it won't contain any logic it will just be a fall-through...

[RoutePrefix("api/Order")]
public class OrderController : ApiController
{
    [Route("~/api/Order/{id}")]
    [HttpGet]
    public virtual Task<HttpResponseMessage> Get(Guid id)
    {
        //Implementation
    }

    [Route("ExampleOtherNormalMethod")]
    [HttpGet]
    public Task<HttpResponseMessage> ExampleOtherNormalMethod()
    {
        //Implementation
    }
}

[RoutePrefix("api/ManualOrder")]
public class ManualOrderController : OrderController 
{
    [Route("~/api/ManualOrder/{id}")]
    [HttpGet]
    public override Task<HttpResponseMessage> Get(Guid id)
    {
        return base.Get(id);
    }

    //Other methods
}

There is a downside to this approach - ManualOrderController will expose methods from OrderController via your default routing table. Depending on what your routing table looks like api/ManualOrder/ExampleOtherNormalMethod may call ExampleOtherNormalMethod on OrderController. This may, or may not, be a desired behavior.