Contao\Widget::getEmptyStringOrNull PHP Method

    public function getEmptyStringOrNull()
    {
        if (!isset($GLOBALS['TL_DCA'][$this->strTable]['fields'][$this->strField]['sql'])) {
            return '';
        }
        return static::getEmptyStringOrNullByFieldType($GLOBALS['TL_DCA'][$this->strTable]['fields'][$this->strField]['sql']);
    }