VS: WebAPI tips

This post will have some WebAPI tips

Last updated: 2015-02-12

Add WebAPI as standalone webapp

In Visual Studio

• New Project – C# – Web – ASP.NET WebApp – Name: MySln.WebAPI – OK
• Template: Either
  • WebAPI //This also gives you MVC template for HelpPages
  • Empty + WebAPI ref //Only WebAPI
• Do also add unit tests
• Goto \MySln.WebAPI\Controllers\ValuesController.cs to see sample methods
• Goto \MySln.WebAPI.Tests\Controllers\ValuesControllerTest.cs to see sample unit tests
• You can also test the method with Chrome PostMan, Fiddler or just from a browser with url http://localhost:9286/api/Values where 9286 is your WebAPI web

Tips

• More info about naming and routing to methods:
  http://www.asp.net/web-api/overview/web-api-routing-and-actions/routing-in-aspnet-web-api
• You might want to fake HttpContext:
  http://stackoverflow.com/questions/9624242/setting-httpcontext-current-session-in-a-unit-test

Include standalone WebAPI webapp in existing MVC web

You can simultaneously use the above MySln.WebAPI project in your existing MySln.SomeMvcWeb webapp with few steps.

• In Package Manager
  • PM> Install-Package Microsoft.AspNet.WebApi -ProjectName MySln.SomeMvcWeb
• In MySln.SomeMvcWeb\Global.asax – Application_Start() – After AreaRegistration.RegisterAllAreas(); add the line
  • GlobalConfiguration.Configure(WebApiConfig.Register);
• Copy MySln.WebAPI\App_Start\WebApiConfig.cs to MySln.SomeMvcWeb\App_Start\ and set its namespace accordingly
• In MySln.SomeMvcWeb add ref to MySln.WebAPI
• Now without writing any code you can use your WebAPI code from your SomeMvcWeb directly by browsing to http://localhost:16661/api/Values where 16661 is your SomeMvcWeb web. Cool :-)

Ref

• http://stackoverflow.com/questions/11990036/how-to-add-web-api-to-an-existing-asp-net-mvc-4-web-application-project
• http://wildermuth.com/2012/2/22/WebAPI_for_the_MVC_Guy

ExceptionMessage”: “Multiple actions were found that match the request”

Calling service with

http://localhost:16661/api/users/IsCurrentUserAuthenticated

throws an exception

{
    "Message": "An error has occurred.",
    "ExceptionMessage": "Multiple actions were found that match the request: \r\nBoolean IsCurrentUserAuthenticated() on type MyProject.WebAPI.Controllers.UsersController\r\nMySln.Services.User.IUserInfo GetUserInfo() on type MySln.WebAPI.Controllers.UsersController",
    "ExceptionType": "System.InvalidOperationException",
    "StackTrace": "   at System.Web.Http.Controllers.ApiControllerActionSelector.ActionSelectorCacheItem.SelectAction(HttpControllerContext controllerContext)\r\n   at System.Web.Http.ApiController.ExecuteAsync(HttpControllerContext controllerContext, CancellationToken cancellationToken)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__0.MoveNext()"
}

UsersController.cs had two actions:

    public class UsersController : ApiController
    {
        [HttpGet]
        public bool IsCurrentUserAuthenticated()
        {
        }
        [HttpGet]
        public IUserInfo GetUserInfo()
        {
        }
    }

But several actions were not in WebApiConfig.cs – Do change from:

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

Do change to

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

Ref:

• http://stackoverflow.com/questions/14534167/multiple-actions-were-found-that-match-the-request-webapi

The end.