What determines whether the "success" or "error" function is called?

Question

I've never understood: What determines whether the success or error function of

$.ajax( { ...,
          success : function ( retobj ) { ... },
          error   : function ( retobj ) { ... },
          ...
          } );

is called? Can my controller directly control which is called? I know it'll be called if my controller does something stupid, but can I force it to be called like

$.ajax( { ...,
          url     : 'MyController/CallSuccess',
          success : function ( retobj ) { /* this will invetiably be called */},
          error   : function ( retobj ) { ... },
          ...
          } );

 public ActionResult CallSuccess ( void )
 {
    // ...
 }

If the http call fails or if the script can not parse the content. — epascarello, Nov 04 '15 at 18:06
Related: http://stackoverflow.com/questions/12112361/how-to-set-http-status-code-from-asp-net-mvc-3 — Stryner, Nov 04 '15 at 18:09
These use the HTTP Status. If the status is 200, it's successful. If it's 400 or 500, these are different errors. What are you trying to accomplish? — Twisty, Nov 04 '15 at 18:10
You can set the status code programmatically ie. `Response.StatusCode = 500;` — Frank Witte, Nov 04 '15 at 19:39

score 0 · Answer 1 · answered Nov 04 '15 at 22:13

Your controller action method can control whether the success or error ajax function will be called via setting the Response.StatusCode in your action method.

If Response.StatusCode = (int)HttpStatusCode.OK then the success function will be called.

If Response.StatusCode = (int)HttpStatusCode.InternalServerError then the error function will be called.

Sample code to invoke success function:

    $.ajax({
      url: 'MyController/CallSuccess',
      success: function(result) { /* this will be called */
        alert('success');
      },
      error: function(jqXHR, textStatus, errorThrown) {
        alert('oops, something bad happened');
      }
    });

    [HttpGet]
    public ActionResult CallSuccess()
    {
        Response.StatusCode = (int)HttpStatusCode.OK;
        return Json(new { data = "success" }, JsonRequestBehavior.AllowGet);
    }

Sample code to invoke error function:

    $.ajax({
      url: 'MyController/CallFailure',
      success: function(result) { 
        alert('success');
      },
      error: function(jqXHR, textStatus, errorThrown) { /* this will be called */
        alert('oops, something bad happened');
      }
    });

    [HttpGet]
    public ActionResult CallFailure()
    {
        Response.StatusCode = (int)HttpStatusCode.InternalServerError;
        return Json(new { data = "error" }, JsonRequestBehavior.AllowGet);
    }

What determines whether the "success" or "error" function is called?

1 Answers1