CIBlock::_Order

static function _Order($by, $order, $default_order, $nullable = true)
{
	$o = parent::_Order($by, $order, $default_order, $nullable);
	//$o[0] - bNullsFirst
	//$o[1] - asc|desc
	if($o[0])
	{
		if($o[1] == "asc")
		{
			return $by." asc";
		}
		else
		{
			return "length(".$by.")>0 asc, ".$by." desc";
		}
	}
	else
	{
		if($o[1] == "asc")
		{
			return "length(".$by.")>0 desc, ".$by." asc";
		}
		else
		{
			return $by." desc";
		}
	}
}