Ajax success event not working

The result is probably not in JSON format, so when jQuery tries to parse it as such, it fails. You can catch the error with error: callback function.

You don't seem to need JSON in that function anyways, so you can also take out the dataType: 'json' row.

Put an alert() in your success callback to make sure it's being called at all.

If it's not, that's simply because the request wasn't successful at all, even though you manage to hit the server. Reasonable causes could be that a timeout expires, or something in your php code throws an exception.

Install the firebug addon for firefox, if you haven't already, and inspect the AJAX callback. You'll be able to see the response, and whether or not it receives a successful (200 OK) response. You can also put another alert() in the complete callback, which should definitely be invoked.

You must declare both Success AND Error callback. Adding

error: function(err) {...} 

should fix the problem

I faced the same problem when querying controller which does not return success response, when modified my controller to return success message problem was solved. note using Lavalite framework. before:

public function Activity($id)
    {
        $data=getData();
        return
            $this->response->title('title')
                ->layout('layout')
                ->data(compact('data'))
                ->view('view')
                ->output();
    }
after code looks like:
    try {
            $attributes = $request->all();
            //do something
            return $this->response->message('')
                ->code(204)
                ->status('success')
                ->url('url'. $data->id)
                ->redirect();
        } catch (Exception $e) {
            return $this->response->message($e->getMessage())
                ->code(400)
                ->status('error')
                ->url('nothing Wrong')
                ->redirect()
        }

this worked for me

I had the same problem i solved it in that way: My ajax:

event.preventDefault();
$.ajax('file.php', {
method: 'POST',
dataType: 'json',
contentType: 'application/json',
data: JSON.stringify({tab}), 
success: function(php_response){
            if (php_response == 'item') 
                {
                    console.log('it works');
                }
            }
        })

Ok. The problem is not with json but only php response. Before: my php response was:

echo 'item';

Now:

$variable = 'item';
 echo json.encode($variable);

Now my success working. PS. Sorry if something is wrong but it is my first comment on this forum :)

Add 'error' callback (just like 'success') this way:

$.ajax({
   type: 'POST',
   url: 'submit1.php',
   data: $("#regist").serialize(),
   dataType: 'json',
   success: function() {
      $("#loading").append("<h2>you are here</h2>");
   },
   error: function(jqXhr, textStatus, errorMessage){
      console.log("Error: ", errorMessage);
   }
});

So, in my case I saw in console:

Error:  SyntaxError: Unexpected end of JSON input
  at parse (<anonymous>), ..., etc.

The success callback takes two arguments:

success: function (data, textStatus) { }

Also make sure that the submit1.php sets the proper content-type header: application/json