ASP.Net WebAPI area support

Question

I am trying to add some WebAPI support to my asp.net 4 RC site, and wish to put it into an area. I have seen that someone managed to get this running on the beta (here) ,

Answer 1

ASP.NET MVC 4 doesn't support WebAPI in Areas.

It is possible to extend DefaultHttpControllerSelector to do this, but you should carefully read this excellent (and short) article: ASP.NET MVC 4 RC: Getting WebApi and Areas to play nicely. It works great.

I've successfully tested this solution with portable areas (MVCContrib). Basically, you have to:

• Put extension methods "AreaRegistrationContextExtensions" in the PA project (required from PortableAreaRegistration.RegisterArea() method): you can copy the static class into the PA project but I suggest to put it into a shared project.
• Add the class "AreaHttpControllerSelector" (inherited from DefaultHttpControllerSelector) into the host project.

• Add to Global.asax App_Start() the following line:

  GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerSelector), new AreaHttpControllerSelector(GlobalConfiguration.Configuration));

There is one caveat with the implementation of AreaHttpControllerSelector: the area name must correspond to the ApiController's namespace. For example, this is my PortableAreaRegistration class:

namespace PortableAreasSample.MembershipArea
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using MvcContrib.PortableAreas;
    using System.Web.Http;
    using System.Web.Mvc;
    using System.Web.Routing;

    public class MembershipRegistration : PortableAreaRegistration
    {
        public override void RegisterArea(System.Web.Mvc.AreaRegistrationContext context, IApplicationBus bus)
        {
            // GET /MembershipArea/GetAllUsers
            context.MapHttpRoute("MembershipApi",
                AreaName + "/{controller}/{id}",
                new { area=AreaName, controller = "GetAllUsers", id = RouteParameter.Optional });
        }

        public override string AreaName
        {
            get { return "MembershipArea"; }
        }
    }
}