Question

I was trying to return an error to the call to the controller as advised in
This link so that client can take appropriate action.
The controller is called by javascript via jquery AJAX. I am getting the Json object back only if I don’t set the status to error.
Here is the sample code

if (response.errors.Length > 0)
   Response.StatusCode = (int)HttpStatusCode.BadRequest;
return Json(response);

I get the Json if I don’t set the statuscode.
If I set the status code I get the status code back but not the Json error object.

Update
I want to send an Error object as JSON so that it can be handled error callback of ajax.

Answer 1

I found the solution here

I had to create a action filter to override the default behaviour of MVC

Here is my exception class

class ValidationException : ApplicationException
{
    public JsonResult exceptionDetails;
    public ValidationException(JsonResult exceptionDetails)
    {
        this.exceptionDetails = exceptionDetails;
    }
    public ValidationException(string message) : base(message) { }
    public ValidationException(string message, Exception inner) : base(message, inner) { }
    protected ValidationException(
    System.Runtime.Serialization.SerializationInfo info,
    System.Runtime.Serialization.StreamingContext context)
        : base(info, context) { }
}

Note that I have constructor which initializes my JSON. Here is the action filter

public class HandleUIExceptionAttribute : FilterAttribute, IExceptionFilter
{
    public virtual void OnException(ExceptionContext filterContext)
    {
        if (filterContext == null)
        {
            throw new ArgumentNullException("filterContext");
        }
        if (filterContext.Exception != null)
        {
            filterContext.ExceptionHandled = true;
            filterContext.HttpContext.Response.Clear();
            filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;
            filterContext.HttpContext.Response.StatusCode = (int)System.Net.HttpStatusCode.InternalServerError;
            filterContext.Result = ((ValidationException)filterContext.Exception).myJsonError;
        }
    }

Now that I have the action filter, I will decorate my controller with the filter attribute

[HandleUIException]
public JsonResult UpdateName(string objectToUpdate)
{
   var response = myClient.ValidateObject(objectToUpdate);
   if (response.errors.Length > 0)
     throw new ValidationException(Json(response));
}

When the error is thrown the action filter which implements IExceptionFilter get called and I get back the Json on the client on error callback.