library/Zend/Validate/Barcode/Ean13.php

   1 <?php
   2
   3 /**
   4  * Zend Framework
   5  *
   6  * LICENSE
   7  *
   8  * This source file is subject to the new BSD license that is bundled
   9  * with this package in the file LICENSE.txt.
  10  * It is also available through the world-wide-web at this URL:
  11  * http://framework.zend.com/license/new-bsd
  12  * If you did not receive a copy of the license and are unable to
  13  * obtain it through the world-wide-web, please send an email
  14  * to license@zend.com so we can send you a copy immediately.
  15  *
  16  * @category   Zend
  17  * @package    Zend_Validate
  18  * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
  19  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  20  * @version    $Id: Ean13.php 16223 2009-06-21 20:04:53Z thomas $
  21  */
  22
  23
  24 /**
  25  * @see Zend_Validate_Abstract
  26  */
  27 require_once 'Zend/Validate/Abstract.php';
  28
  29
  30 /**
  31  * @category   Zend
  32  * @package    Zend_Validate
  33  * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
  34  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  35  */
  36 class Zend_Validate_Barcode_Ean13 extends Zend_Validate_Abstract
  37 {
  38     /**
  39      * Validation failure message key for when the value is
  40      * an invalid barcode
  41      */
  42     const INVALID = 'invalid';
  43
  44     /**
  45      * Validation failure message key for when the value is
  46      * not 13 characters long
  47      */
  48     const INVALID_LENGTH = 'invalidLength';
  49
  50     /**
  51      * Validation failure message key for when the value
  52      * does not only contain numeric characters
  53      */
  54     const NOT_NUMERIC = 'ean13NotNumeric';
  55
  56     /**
  57      * Validation failure message template definitions
  58      *
  59      * @var array
  60      */
  61     protected $_messageTemplates = array(
  62         self::INVALID        => "'%value%' is an invalid EAN-13 barcode",
  63         self::INVALID_LENGTH => "'%value%' should be 13 characters",
  64         self::NOT_NUMERIC    => "'%value%' should contain only numeric characters",
  65     );
  66
  67     /**
  68      * Defined by Zend_Validate_Interface
  69      *
  70      * Returns true if and only if $value contains a valid barcode
  71      *
  72      * @param  string $value
  73      * @return boolean
  74      */
  75     public function isValid($value)
  76     {
  77         if (!is_string($value) || !ctype_digit($value)) {
  78             $this->_error(self::NOT_NUMERIC);
  79             return false;
  80         }
  81
  82         $this->_setValue($value);
  83         if (strlen($value) !== 13) {
  84             $this->_error(self::INVALID_LENGTH);
  85             return false;
  86         }
  87
  88         $barcode = strrev(substr($value, 0, -1));
  89         $oddSum  = 0;
  90         $evenSum = 0;
  91
  92         for ($i = 0; $i < 12; $i++) {
  93             if ($i % 2 === 0) {
  94                 $oddSum += $barcode[$i] * 3;
  95             } elseif ($i % 2 === 1) {
  96                 $evenSum += $barcode[$i];
  97             }
  98         }
  99
 100         $calculation = ($oddSum + $evenSum) % 10;
 101         $checksum    = ($calculation === 0) ? 0 : 10 - $calculation;
 102
 103         if ($value[12] != $checksum) {
 104             $this->_error(self::INVALID);
 105             return false;
 106         }
 107
 108         return true;
 109     }
 110 }