FolderListOptions::getSortingColumns

public function getSortingColumns()
{
	$gridSort = $this->getGridOptions()->getSorting(array(
		'sort' => $this->getDefaultSorting(),
		'vars' => array('by' => 'by', 'order' => 'order')
	));
	$sorting = $gridSort['sort'];
	$possibleColumnForSorting = $this->getPossibleColumnForSorting();

	$byColumn = key($sorting);
	if(!isset($possibleColumnForSorting[$byColumn]) || (mb_strtolower($sorting[$byColumn]) !== 'desc' && mb_strtolower($sorting[$byColumn]) !== 'asc'))
	{
		$sorting = array();
	}

	$order = $sorting;
	$byColumn = key($order);
	$sortingColumns = array();
	if(!$this->isMixSortMode())
	{
		$sortingColumns['TYPE'] = array(SORT_NUMERIC, SORT_ASC);
	}

	if(isset($possibleColumnForSorting[$byColumn]['ALIAS']))
	{
		$sortingColumns[$possibleColumnForSorting[$byColumn]['ALIAS']] = mb_strtolower($order[$byColumn]) === 'asc' ? SORT_ASC : SORT_DESC;
	}

	if($byColumn !== 'NAME')
	{
		$sortingColumns[$possibleColumnForSorting['NAME']['ALIAS']] = SORT_ASC;
	}

	return $sortingColumns;
}