IRestService::sanitizeOrder

static function sanitizeOrder($order, array $availableFields = null)
{
	if(!is_array($order))
	{
		throw new RestException('The order is not an array.', RestException::ERROR_ARGUMENT, CRestServer::STATUS_WRONG_REQUEST);
	}

	$order = array_change_key_case($order, CASE_UPPER);

	foreach($order as $key => $value)
	{
		if(!is_numeric($key))
		{
			if($availableFields !== null && !in_array($key, $availableFields))
			{
				throw new RestException('Order field not allowed: '.$key, RestException::ERROR_ARGUMENT, CRestServer::STATUS_WRONG_REQUEST);
			}

			if(!in_array(ToUpper($value), array('ASC', 'DESC')))
			{
				throw new RestException('Order direction should be one of {ASC|DESC}', RestException::ERROR_ARGUMENT, CRestServer::STATUS_WRONG_REQUEST);
			}
		}
		elseif($availableFields !== null && !in_array($value, $availableFields))
		{
			throw new RestException('Order field not allowed: '.$value, RestException::ERROR_ARGUMENT, CRestServer::STATUS_WRONG_REQUEST);
		}
	}

	return $order;
}