ASP MVC and JsonResult in case of error

Question

In ASP MVC I have a controller that returns json data:

public JsonResult Edit(int? id)
{
   if(id==null)
   {
      Response.StatusCode = (int)HttpStatusCode.BadRequest;
      return Json(new { message = "Bad Request" }, JsonRequestBehavior.AllowGet);
   }

   car carTmp = db.car.Find(id);
   if (carTmp == null)
   {
      Response.StatusCode = (int)HttpStatusCode.NotFound;
      return Json(new { message = "Not Found" }, JsonRequestBehavior.AllowGet);
   }

   return Json(carTmp, JsonRequestBehavior.AllowGet);
}

I also have the following ajax request:

$.getJSON("Edit/" + data, function (result) {
            var car = result;
        })
        .error(function (error) {
            alert(error.message);
        })

Why, in case of success, in the result object I have the json object (i.e: I can access result.id, result.name ecc...) but in case of error, error.message is undefined? (I have the message into error.responseJson.message)

Answer 1

You are setting the status code in the response as 404 so the error callback should be executed.

The problem is that the error callback is defined as function( jqXHR, textStatus, errorThrown ), where the jqxhr will have a responseJSON property.

You just need to change your code as:

$.getJSON("Edit/" + data, function (result) {
    var car = result;
})
.error(function (xhr) {
    alert(xhr.responseJSON.message);
})