Simple controller which takes POST is not found

Question

I've made some previous question asking for the help with the problems since I updated MVC4 webapi beta to RC. I got most in order now, but here's one I cannot figure out the reason for yet.

For this simple controller I have one which accepts a POST and one that accepts GET. When I try to run those by sending request from a HTML form, only the GET controller is found while the POST one will return me the following error.

{   "Message": "No HTTP resource was found that matches the request URI 'http://localhost/webapi/api/play/test'.",   "MessageDetail": "No action was found on the controller 'Play' that matches the name 'test'." } 

Why is the POST controller not found?

Controllers

public class PlayController : ApiController {     [HttpPost]  // not found     public string Test(string output)     {         return output;     }      [HttpGet]  // works     public string Test2(string output)     {         return output;     } } 

HTML form

<form action="http://localhost/webapi/api/play/test" method="post"> <input type="text" name="output" /> <input type="submit" name="submit" /> </form>  <form action="http://localhost/webapi/api/play/test2" method="get"> <input type="text" name="output" /> <input type="submit" name="submit" /> </form> 

Answer 1

Web.API is a little bit picky when you want to post "simple" values.

You need to use the [FromBody] attribute to signal that the value is not coming from the URL but from the posted data:

[HttpPost] public string Test([FromBody] string output) {     return output; } 

With this change you won't get 404 anymore but output will be always null, because Web.Api requries the posted values in special format (look for the Sending Simple Types section):

Second, the client needs to send the value with the following format:

=value

Specifically, the name portion of the name/value pair must be empty for a simple type. Not >all browsers support this for HTML forms, but you create this format in script...

So recommend that you should create a model type:

public class MyModel {     public string Output { get; set; } }  [HttpPost] public string Test(MyModel model) {     return model.Output; } 

Then it will work with your sample froms without modifing your views.