function addfieldconfigurer(callable $configurer, $fieldtypes = null) {
		$fieldtypes != null or $fieldtypes = 'field';
		is_array($fieldtypes) or $fieldtypes = [$fieldtypes];

		foreach ($fieldtypes as $fieldtype) {
			$this->fieldconfigurers[$fieldtype] = $configurer;
		}

		return $this;
	}