FileModel::onBeforeDelete

static function onBeforeDelete(Event $event)
{
	$result = new MainEntityEventResult();
	$eventData = $event->getParameters();
	$data = static::getById($eventData['primary']['ID'])->fetch();
	foreach(static::$fileFieldNames as $name)
	{
		if($data[$name])
		{
			static::$filesToDelete[] = $data[$name];
		}
	}
	return $result;
}