ASP.NET MVC JsonResult not returning responseText in jQuery.post fail callback function

Question

I am using jQuery $.post to post some data to an ActionResult method inside my controller. When an error is thrown in the controller, it should return the error message within the responseText of the response but it's not working.

The post request is hitting the controller.

The callback function fail seems to be triggered. Just not getting the error message returned. Not sure what I am doing wrong?

This is jQuery posting data:

var postData = ["1","2","3"];

$.post('/MyController/GetSomething', $.param(postData, true))
      .done(function (data) {
              alert('Done!');                        
      })
      .fail(function (xhr, textStatus, errorThrown) {
              alert(xhr.responseText); //xhr.responseText is empty   
      });
 });

Controllers


    public class MyController : BaseController
    {
        public ActionResult GetSomething(List ids)
        {
            try
            {
                GetSomeData(ids);
            }
            catch (Exception ex)
            {
                return ThrowJsonError(new Exception(String.Format("The following error occurred: {0}", ex.ToString())));
            }

            return RedirectToAction("Index");
        }
    }

    public class BaseController : Controller
    {
        public JsonResult ThrowJsonError(Exception ex)
        {
            Response.StatusCode = (int)System.Net.HttpStatusCode.BadRequest;
            Response.StatusDescription = ex.Message;

            return Json(new { Message = ex.Message }, JsonRequestBehavior.AllowGet);
        }
    }

Update What's interesting is that if I move some of the logic from out of the BaseController and into the MyController, I am able to get the desired result.

Why would this happen?

public class MyController : BaseController
    {
        public ActionResult GetSomething(List<string> ids)
        {
            try
            {
                GetSomeData(ids);
            }
            catch (Exception ex)
            {
                Response.StatusCode = (int)System.Net.HttpStatusCode.BadRequest;
                Response.StatusDescription = ex.Message;

                return Json(new { Message = ex.Message }, JsonRequestBehavior.AllowGet);
            }

            return RedirectToAction("Index");
        }
    }

Yes, it does reach the controller. If an exception is then thrown in the Controller then the Message doesn't come back as xhr.ResponseText = "" — jgill09
– jgill09, Commented Sep 29, 2016 at 17:28
if you put alert(data.Message); before alert('Done!'); what happend? — DanielVorph
– DanielVorph, Commented Sep 29, 2016 at 17:28
I've some question here, what is in GetSomeData(ids); after this you redirect to index action, what is in Index and you had not passed any data from GetSomething to index — Divyang Desai
– Divyang Desai, Commented Sep 29, 2016 at 17:33
@DanielVorph When the exception is thrown in the Controller, I am definitely hitting the .fail(function (xhr, textStatus, errorThrown) { alert(xhr.responseText); //xhr.responseText is empty }); function. — jgill09
– jgill09, Commented Sep 29, 2016 at 17:33

Community · Accepted Answer · 2017-05-23 10:27:46Z

2

This is occurring because you have an invalid StatusDescription being set in the ThrowJsonError function. It has line feed characters which cause unexpected results in an Http Header. See this related question

The issue is being obfuscated because your first example has you set the StatusDescription to the Message property of a new Exception you are constructing which will contain line feeds and stack trace info because you call ex.ToString(). The second one works because you are just setting the StatusDescription to ex.Message and that doesn't contain problematic characters

To be safe, you probably should just use a relatively benign StatusDescription since you don't really need it for anything anyway (you can get the Message in the fail() either way.

Note the following code works (still do not recommend it):

public ActionResult ThrowJsonError(Exception ex)
{
   Response.StatusCode = (int)System.Net.HttpStatusCode.BadRequest;
   Response.StatusDescription = ex.Message; // does not work
   Response.StatusDescription = ex.Message.Replace('\r', ' ').Replace('\n', ' '); // works

   return Json(new { Message = ex.Message }, JsonRequestBehavior.AllowGet);
}

edited May 23, 2017 at 10:27

CommunityBot

11 silver badge

answered Sep 29, 2016 at 18:57

steve v

3,5501 gold badge20 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

jgill09 Over a year ago

Ah understood. Thank you for helping and taking the time to explain.

Collectives™ on Stack Overflow

ASP.NET MVC JsonResult not returning responseText in jQuery.post fail callback function

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related