public function select($source) {
		$relation = $this->getFileName($source->get_relation());
		// for tree checks relation id and forms absolute path
		if ($relation == '0') {
			$relation = '';
		} else {
			$path = $source->get_source();
		}
		$path = $source->get_source();
		$path = $this->getFileName($path);
		$path = realpath($path);
		if ($path == false) {
			return new FileSystemResult();
		}
		
		if (strpos(realpath($path.'/'.$relation), $path) !== 0) {
			return new FileSystemResult();
		}
		// gets files and directories list
		$res = $this->getFilesList($path, $relation);
		// sorts list
		$res = $res->sort($source->get_sort_by(), $this->config->data);
		return $res;
	}