public static function getUpgradePath($url, $format = "php", $channel = "stable")
 {
     $packageName = "pydio-core";
     if (defined('AJXP_PACKAGE_NAME')) {
         $packageName = AJXP_PACKAGE_NAME;
     }
     $packageName .= ConfService::getInfo();
     if (isset(self::$context)) {
         $json = file_get_contents($url . "?channel=" . $channel . "&version=" . AJXP_VERSION . "&package=" . $packageName, null, self::$context);
     } else {
         $json = AJXP_Utils::getRemoteContent($url . "?channel=" . $channel . "&version=" . AJXP_VERSION . "&package=" . $packageName);
     }
     if ($format == "php") {
         return json_decode($json, true);
     } else {
         return $json;
     }
 }