OctoberCMS callback for successful DB action after AJAX request - php

Question

Im sending data via AJAX from my Chrome-extension to my OctoberCMS controller.
How can I recognize in my Chrome-extension that the database operation was successful?
So the goal is that I can use the done() in my AJAX call after a successful database update.
Do I have to return something from my controller?
Ajax from extension
$.ajax({
headers: {
'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
},
url: "/saveData",
type: "POST",
dataType: "JSON",
data: { "data": data}
}).done(function((){//does nothing});
OctoberCMS Controller
function saveData(Request $request)
{
$data = post('data');
//do some actions with the data;
DB::table('users')->where(['id' => Auth::getUser()->id])->update(['data' => $data]);
}

Answer 1

You can check for response
From server side
function saveData(Request $request)
{
$data = post('data');
//do some actions with the data;
DB::table('users')->where(['id' => Auth::getUser()->id])->update(['data' => $data]);
// if all good return success
return ['success' => true];
// if something is not correct
// return ['success' => false];
}
Client side
$.ajax({
headers: {
'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
},
url: "/saveData",
type: "POST",
dataType: "JSON",
data: { "data": data}
}).done(function((data){
if(data.success == true) {
// yes all good data is updated
}
else {
// data is not updated some error handling
}
}).fail(function() {
// data is not updated some error handling
// failed in case server is not able to answer or error
});
if any doubt please comment.