将javascript代码中的字符串发布到服务器上的ApiController

Question

I start to play with ASP.NET Web API. I am wondering with serialization feature when I get my entity in the Controler like next:

public class EntitiesController : ApiController
{
    [Queryable]
    public IEnumerable<Entity> Get()
    {
        return m_repository.GetAll();
    }
    public HttpResponseMessage Post(Entity entity)
    {
        if (ModelState.IsValid)
        {
            m_repository.Post(entity);
            var response = Request.CreateResponse<Entity>(HttpStatusCode.Created, entity);
            return response;
        }
        return Request.CreateResponse(HttpStatusCode.BadRequest);
    }
}

and on the JavaScript side:

// create new entity.
$.post("api/entities", $(formElement).serialize(), "json")
    .done(function (newEntity) { self.contacts.push(newEntity); });

But I don't need entity. I want to receive string. So I've changed controller in the next manner:

public class EntitiesController : ApiController
{
    [Queryable]
    public IEnumerable<string> Get()
    {
        return m_repository.GetAll();
    }
    public HttpResponseMessage Post(string entity)
    {
        if (ModelState.IsValid)
        {
            m_repository.Post(entity);
            var response = Request.CreateResponse<Entity>(HttpStatusCode.Created, entity);
            return response;
        }
        return Request.CreateResponse(HttpStatusCode.BadRequest);
    }
}

I tried to different dataType ( "json" , "text" , "html" ) for post function . and different data representation $(formElement).serialize() , "simple Text" , jsonObject , JSON.stringify(jsonObject) . But I always get null on server side as entity parameter in the Post action.

What am I doing wrong?

Answer 1

If you want to post your form data as a string you need to do two things:

By default, Web API tries to get simple types like int , string etc. from the request URI. You need to use FromBody attribute tells Web API to read the value from the request body:

public HttpResponseMessage Post([FromBody]string entity)
{
   //...
}

And you need to post your value with an empty key:

$.post("api/entities", { "": $(formElement).serialize() }, "json")
    .done(function (newEntity) { self.contacts.push(newEntity); });

You can read more about this Web.API tutorial article: Sending HTML Form Data

Answer 2

Could you post the HTML for the form that you're using with serialize? I'm guessing you're missing the name attribute from the particular element you are selecting.

As for the AJAX request, I tend to use the "perfect ajax request" template by Kyle Schaeffer; It's more readable and allows for better result handling IMHO, at least in older versions of jQuery.

$.ajax({
  type: 'POST',
  url: 'api/entities',
  data: { postVar1: 'theValue1', postVar2: 'theValue2' },
  beforeSend:function(){
  },
  success:function(data){
  },
  error:function(){
  }
});

Refer to: http://kyleschaeffer.com/development/the-perfect-jquery-ajax-request/

Answer 3

Try

$.ajax({
  type: 'POST',
  url: 'api/entities',
   traditional: true,

.....