1 <?php

     2 /**

     3  * Zend Framework

     4  *

     5  * LICENSE

     6  *

     7  * This source file is subject to the new BSD license that is bundled

     8  * with this package in the file LICENSE.txt.

     9  * It is also available through the world-wide-web at this URL:

    10  * http://framework.zend.com/license/new-bsd

    11  * If you did not receive a copy of the license and are unable to

    12  * obtain it through the world-wide-web, please send an email

    13  * to license@zend.com so we can send you a copy immediately.

    14  *

    15  * @category   Zend

    16  * @package    Zend_Memory

    17  * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

    18  * @license    http://framework.zend.com/license/new-bsd     New BSD License

    19  * @version    $Id: Value.php 20096 2010-01-06 02:05:09Z bkarwin $

    20  */

    21 

    22 

    23 /**

    24  * String value object

    25  *

    26  * It's an OO string wrapper.

    27  * Used to intercept string updates.

    28  *

    29  * @category   Zend

    30  * @package    Zend_Memory

    31  * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

    32  * @license    http://framework.zend.com/license/new-bsd     New BSD License

    33  * @todo       also implement Countable for PHP 5.1 but not yet to stay 5.0 compatible

    34  */

    35 class Zend_Memory_Value implements ArrayAccess {

    36     /**

    37      * Value

    38      *

    39      * @var string

    40      */

    41     private $_value;

    42 

    43     /**

    44      * Container

    45      *

    46      * @var Zend_Memory_Container_Interface

    47      */

    48     private $_container;

    49 

    50     /**

    51      * Boolean flag which signals to trace value modifications

    52      *

    53      * @var boolean

    54      */

    55     private $_trace;

    56 

    57 

    58     /**

    59      * Object constructor

    60      *

    61      * @param string $value

    62      * @param Zend_Memory_Container_Movable $container

    63      */

    64     public function __construct($value, Zend_Memory_Container_Movable $container)

    65     {

    66         $this->_container = $container;

    67 

    68         $this->_value = (string)$value;

    69 

    70         /**

    71          * Object is marked as just modified by memory manager

    72          * So we don't need to trace followed object modifications and

    73          * object is processed (and marked as traced) when another

    74          * memory object is modified.

    75          *

    76          * It reduces overall numberr of calls necessary to modification trace

    77          */

    78         $this->_trace = false;

    79     }

    80 

    81 

    82     /**

    83      * ArrayAccess interface method

    84      * returns true if string offset exists

    85      *

    86      * @param integer $offset

    87      * @return boolean

    88      */

    89     public function offsetExists($offset)

    90     {

    91         return $offset >= 0  &&  $offset < strlen($this->_value);

    92     }

    93 

    94     /**

    95      * ArrayAccess interface method

    96      * Get character at $offset position

    97      *

    98      * @param integer $offset

    99      * @return string

   100      */

   101     public function offsetGet($offset)

   102     {

   103         return $this->_value[$offset];

   104     }

   105 

   106     /**

   107      * ArrayAccess interface method

   108      * Set character at $offset position

   109      *

   110      * @param integer $offset

   111      * @param string $char

   112      */

   113     public function offsetSet($offset, $char)

   114     {

   115         $this->_value[$offset] = $char;

   116 

   117         if ($this->_trace) {

   118             $this->_trace = false;

   119             $this->_container->processUpdate();

   120         }

   121     }

   122 

   123     /**

   124      * ArrayAccess interface method

   125      * Unset character at $offset position

   126      *

   127      * @param integer $offset

   128      */

   129     public function offsetUnset($offset)

   130     {

   131         unset($this->_value[$offset]);

   132 

   133         if ($this->_trace) {

   134             $this->_trace = false;

   135             $this->_container->processUpdate();

   136         }

   137     }

   138 

   139 

   140     /**

   141      * To string conversion

   142      *

   143      * @return string

   144      */

   145     public function __toString()

   146     {

   147         return $this->_value;

   148     }

   149 

   150 

   151     /**

   152      * Get string value reference

   153      *

   154      * _Must_ be used for value access before PHP v 5.2

   155      * or _may_ be used for performance considerations

   156      *

   157      * @internal

   158      * @return string

   159      */

   160     public function &getRef()

   161     {

   162         return $this->_value;

   163     }

   164 

   165     /**

   166      * Start modifications trace

   167      *

   168      * _Must_ be used for value access before PHP v 5.2

   169      * or _may_ be used for performance considerations

   170      *

   171      * @internal

   172      */

   173     public function startTrace()

   174     {

   175         $this->_trace = true;

   176     }

   177 }