public function getThumbUrl() {

		if( $this->changed ) {

			return Yii::$app->fileManager->uploadUrl . '/' . CoreProperties::DIR_TEMP . $this->directory . "/" . $this->name . "-thumb." . $this->extension;
		}
		else if( $this->id > 0 ) {

			return Yii::$app->fileManager->uploadUrl . '/' . $this->thumb;
		}

		return "";
	}