GET Json API Results - php

Question

I searched for this but most of the questions related to this are for API's with other services.
I'm building an API that allows game developers to send and retrieve user info from my database.
I was finally able to put together the API, but now I need to call the API.
1st when the game initiates, it sends us the game developers key their developer id and game id.
//Game loads, get developer key, send token and current high score
// == [ FIRST FILTER - FILTER GET REQUEST ] == //
$_GET = array_map('_INPUT', $_GET); // filter all input
// ====================================== //
// ============[ ACTION MENU ]=========== //
// ====================================== //
if(!empty($_GET['action']) && !empty($_GET['user']) && !empty($_GET['key']) && !empty($_GET['email']) && !empty($_GET['password'])): // if key data exists
switch($_GET['action']):
//athenticate game developer return and high score
case 'authenticate':
$db = new PDO('mysql:host=localhost;dbname=xxxx', 'xxxx', 'xxxx');
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
$st = $db->prepare("SELECT * FROM `game_developers_games` WHERE `id` = :gameid AND `developer_id`=:user AND `key`= :key AND `developer_active` = '1'"); // need to filter for next auction
$st->bindParam(':user', $_GET['user']); // filter
$st->bindParam(':key', $_GET['key']); // filter
$st->execute();
$r = $st->fetch(PDO::FETCH_ASSOC);
if($st->rowCount() == 0):
$return = array('DBA_id'=>'0000');
echo json_encode($return);
else:
$token = initToken($_GET['key'],$_GET['user']);
if($token == $r['API_Token']):
$return = array(
'DBA_id'=>$token,
'DBA_servertime'=>time(),
'DBA_highscore'=>$r['score'],
);
echo json_encode($return);
endif;
endif;
break;
Here's the script the game developer will have to add to their game to get the data when the game loads. Found this on another stackoverflow question but it's not working.
$.getJSON("https://www.gamerholic.com/gamerholic_api/db_api_v1.php? user=1&key=6054abe3517a4da6db255e7fa27f4ba001083311&gameid=1&action=authenticate", function () {
alert("aaa");
});

Answer 1

Try adding &callback=? to the end of the url you are constructing. This will enable jsonp that is accepted by cors.
$.getJSON("https://www.gamerholic.com/gamerholic_api/db_api_v1.php?user=1&key=6054abe3517a4da6db255e7fa27f4ba001083311&gameid=1&action=authenticate&callback=?", function () {
alert("aaa");
});

Answer 2

As per cross domain origin policy you cannot access cross domain url using jquery getJson function.
A callback is required to manage cross domain request using json and it needs to be handled on the server as well as the client end.
Also make sure to check the response using firebug or similar tool because as of now it is returning response code as 200.
I am mentioning two threads here which can guide you the right way
Jquery getJSON cross domain problems
http://www.fbloggs.com/2010/07/09/how-to-access-cross-domain-data-with-ajax-using-jsonp-jquery-and-php/