RestService::getAppId

static function getAppId($clientId)
{
	if (!Loader::includeModule('rest'))
	{
		return null;
	}

	$iterator = AppTable::getList(
		array(
			'filter' => array(
				'=CLIENT_ID' => $clientId
			),
			'select' => array('ID'),
		)
	);
	$app = $iterator->fetch();

	return (int) $app['ID'];
}