name::__construct

public function __construct($name, $expression, $buildFrom = null, $parameters = array())
{
	if (!isset($parameters['data_type']))
	{
		$parameters['data_type'] = 'string'; // deprecated

		$this->valueType = StringField::class;
	}

	parent::__construct($name, $parameters);

	$this->expression = $expression;

	if (!is_array($buildFrom) && $buildFrom !== null)
	{
		$buildFrom = array($buildFrom);
	}
	elseif ($buildFrom === null)
	{
		$buildFrom = array();
	}

	$this->buildFrom = $buildFrom;
}