how to return MVC modal in JsonResult in Ajax call?

Question

How to return MVC model in JsonResult in Ajax call? in below example in I can return contact object with result and catch that in ajax success callback.

C#

  [HttpPost]
    public JsonResult Index(Contact contact)
    {
        if (ModelState.IsValid)
        {
           //send contact object with result

           var result = new { Success = "true", Message = "No Error" };
           return Json(result, JsonRequestBehavior.DenyGet);

        }
        else
        {
            var result = new { Success = "false", Message = "Invalid state" };
            return Json(result, JsonRequestBehavior.DenyGet);
        }
    }

JavaScript

 $.ajax({
            url: this.action,
            type: 'POST',
            data: formData,
            mimeType: "multipart/form-data",
            contentType: false,
            cache: false,
            processData: false,
            success: function (result) {
                var obj = jQuery.parseJSON(result);
               //need to access contact data here.
              updateSuccess(obj);

            },
            error: function(jqXHR, textStatus, errorThrown) {
                //alert("Fail");

            }
        });

Answer 1

If you need to return the Contact object, then return it. Something like this:

return Json(contact, JsonRequestBehavior.DenyGet);

Then in your JavaScript:

success: function (result) {
    var obj = jQuery.parseJSON(result);
    // obj is an instance of Contact, at least in terms of the DTO data expressed in JSON
}

If you need to return both, then just add it as part of the anonymous type:

var result = new { Success = "true", Message = "No Error", Contact = contact };
return Json(result, JsonRequestBehavior.DenyGet);

Then in your JavaScript:

success: function (result) {
    var obj = jQuery.parseJSON(result);
    // obj.Contact is an instance of Contact, at least in terms of the DTO data expressed in JSON
    updateSuccess(obj);
}

Of course, it's also worth noting that unless your server-side code is modifying the Contact in some way, you're just returning something that the client-side code sent in the first place. Which means it's already available client-side in some way, basically in the formData object. So you might not need to return it (unless there's more going on here that you removed from the example).