1, '1' => 1, '2' => 1, '3' => 1, '4' => 1, '5' => 1, '6' => 2, '7' => 2, '8' => 2, '9' => 2, 'A' => 2, 'B' => 2, 'C' => 3, 'D' => 3, 'E' => 3, 'F' => 3, 'G' => 3, 'H' => 3, 'I' => 4, 'J' => 4, 'K' => 4, 'L' => 4, 'M' => 4, 'N' => 4, 'O' => 5, 'P' => 5, 'Q' => 5, 'R' => 5, 'S' => 5, 'T' => 5, 'U' => 0, 'V' => 0, 'W' => 0, 'X' => 0, 'Y' => 0, 'Z' => 0, ); protected $_columns = array( '0' => 1, '1' => 2, '2' => 3, '3' => 4, '4' => 5, '5' => 0, '6' => 1, '7' => 2, '8' => 3, '9' => 4, 'A' => 5, 'B' => 0, 'C' => 1, 'D' => 2, 'E' => 3, 'F' => 4, 'G' => 5, 'H' => 0, 'I' => 1, 'J' => 2, 'K' => 3, 'L' => 4, 'M' => 5, 'N' => 0, 'O' => 1, 'P' => 2, 'Q' => 3, 'R' => 4, 'S' => 5, 'T' => 0, 'U' => 1, 'V' => 2, 'W' => 3, 'X' => 4, 'Y' => 5, 'Z' => 0, ); /** * Checksum function * @var string */ protected $_checksum = '_royalmail'; /** * Validates the checksum () * * @param string $value The barcode to validate * @return boolean */ protected function _royalmail($value) { $checksum = substr($value, -1, 1); $values = str_split(substr($value, 0, -1)); $rowvalue = 0; $colvalue = 0; foreach($values as $row) { $rowvalue += $this->_rows[$row]; $colvalue += $this->_columns[$row]; } $rowvalue %= 6; $colvalue %= 6; $rowchkvalue = array_keys($this->_rows, $rowvalue); $colchkvalue = array_keys($this->_columns, $colvalue); $chkvalue = current(array_intersect($rowchkvalue, $colchkvalue)); if ($chkvalue == $checksum) { return true; } return false; } /** * Allows start and stop tag within checked chars * * @param string $value The barcode to check for allowed characters * @return boolean */ public function checkChars($value) { if ($value[0] == '(') { $value = substr($value, 1); if ($value[strlen($value) - 1] == ')') { $value = substr($value, 0, -1); } else { return false; } } return parent::checkChars($value); } }