public function checkChars($value)
    {
        if (strlen($value) != 8) {
            if (strpos($value, 'X') !== false) {
                return false;
            }
        }

        return parent::checkChars($value);
    }
public function checkChars($value)
    {
        if (strlen($value) != 8) {
            if (strpos($value, 'X') !== false) {
                return false;
            }
        }

        return parent::checkChars($value);
    }
public function checkChars ( $ value ) { if ( strlen ( $ value ) != 8 ) { if ( strpos ( $ value , 'X' ) !== false ) { return false ; } } return parent :: checkChars ( $ value ) ; }
Allows X on length of 8 chars

@param  string $value The barcode to check for allowed characters
@return boolean
Allows X on length of 8 chars