interface/modules/zend_modules/library/Zend/Paginator/SerializableLimitIterator.php

   1 <?php
   2 /**
   3  * Zend Framework (http://framework.zend.com/)
   4  *
   5  * @link      http://github.com/zendframework/zf2 for the canonical source repository
   6  * @copyright Copyright (c) 2005-2013 Zend Technologies USA Inc. (http://www.zend.com)
   7  * @license   http://framework.zend.com/license/new-bsd New BSD License
   8  */
   9
  10 namespace Zend\Paginator;
  11
  12 use ArrayAccess;
  13 use Iterator;
  14 use LimitIterator;
  15 use Serializable;
  16
  17 class SerializableLimitIterator extends LimitIterator implements Serializable, ArrayAccess
  18 {
  19
  20     /**
  21      * Offset to first element
  22      *
  23      * @var int
  24      */
  25     private $offset;
  26
  27     /**
  28      * Maximum number of elements to show or -1 for all
  29      *
  30      * @var int
  31      */
  32     private $count;
  33
  34     /**
  35      * Construct a Zend\Paginator\SerializableLimitIterator
  36      *
  37      * @param Iterator $it Iterator to limit (must be serializable by un-/serialize)
  38      * @param int $offset Offset to first element
  39      * @param int $count Maximum number of elements to show or -1 for all
  40      * @see LimitIterator::__construct
  41      */
  42     public function __construct(Iterator $it, $offset=0, $count=-1)
  43     {
  44         parent::__construct($it, $offset, $count);
  45         $this->offset = $offset;
  46         $this->count = $count;
  47     }
  48
  49     /**
  50      * @return string representation of the instance
  51      */
  52     public function serialize()
  53     {
  54         return serialize(array(
  55             'it'     => $this->getInnerIterator(),
  56             'offset' => $this->offset,
  57             'count'  => $this->count,
  58             'pos'    => $this->getPosition(),
  59         ));
  60     }
  61
  62     /**
  63      * @param string $data representation of the instance
  64      * @return void
  65      */
  66     public function unserialize($data)
  67     {
  68         $dataArr = unserialize($data);
  69         $this->__construct($dataArr['it'], $dataArr['offset'], $dataArr['count']);
  70         $this->seek($dataArr['pos']+$dataArr['offset']);
  71     }
  72
  73     /**
  74      * Returns value of the Iterator
  75      *
  76      * @param int $offset
  77      * @return mixed
  78      */
  79     public function offsetGet($offset)
  80     {
  81         $currentOffset = $this->key();
  82         $this->seek($offset);
  83         $current = $this->current();
  84         $this->seek($currentOffset);
  85         return $current;
  86     }
  87
  88     /**
  89      * Does nothing
  90      * Required by the ArrayAccess implementation
  91      *
  92      * @param int $offset
  93      * @param mixed $value
  94      */
  95     public function offsetSet($offset, $value)
  96     {
  97     }
  98
  99     /**
 100      * Determine if a value of Iterator is set and is not NULL
 101      *
 102      * @param int $offset
 103      * @return bool
 104      */
 105     public function offsetExists($offset)
 106     {
 107         if ($offset > 0 && $offset < $this->count) {
 108             try {
 109                 $currentOffset = $this->key();
 110                 $this->seek($offset);
 111                 $current = $this->current();
 112                 $this->seek($currentOffset);
 113                 return null !== $current;
 114             } catch (\OutOfBoundsException $e) {
 115                 // reset position in case of exception is assigned null
 116                 $this->seek($currentOffset);
 117                 return false;
 118             }
 119         }
 120         return false;
 121     }
 122
 123     /**
 124      * Does nothing
 125      * Required by the ArrayAccess implementation
 126      *
 127      * @param int $offset
 128      */
 129     public function offsetUnset($offset)
 130     {
 131     }
 132 }