public function toDatatablesString() {
		$string = "";
		$fields = $this::getFields ();
		foreach ( $fields as $field ) {
			$value = call_user_func ( array (
					$this,
					'get' . $field 
			) );
			if ($value instanceof \DateTime) {
				$value = $value->format ( 'Y-m-d' );
			}
			$string .= $value . ",";
		}
		$string = trim ( $string, "," );
		$string = str_replace ( "\n", "", $string );
		return $string;
	}