private function GetThumbnailFileName($original_file_name, $original_file_extension, $file_size)
{
$result = '';
$handled = false;
$this->generateFileNameDelegate->CallFromArray(array(&$result, &$handled, $original_file_name, $original_file_extension, $file_size));
$targetFolder = FormatDatasetFieldsTemplate($this->GetDataset(), $this->directoryToSaveThumbnails);
FileUtils::ForceDirectories($this->directoryToSaveThumbnails);
if (!$handled) {
$filename = FileUtils::AppendFileExtension(rand(), $original_file_extension);
$result = Path::Combine($targetFolder, $filename);
while (file_exists($result)) {
$filename = FileUtils::AppendFileExtension(rand(), $original_file_extension);
$result = Path::Combine($targetFolder, $filename);
}
}
return $result;
}