Prado\Web\UI\WebControls\TRegularExpressionValidator::getRegularExpression PHP Method

    public function getRegularExpression()
    {
        return $this->getViewState('RegularExpression', '');
    }

 /**
  * @return string the regular expression that determines the pattern used to validate a field.
  */
 public function getRegularExpression()
 {
     $regex = parent::getRegularExpression();
     return $regex === '' ? self::EMAIL_REGEXP : $regex;
 }