/framework/vendor/zend/Zend/Memory/Value.php

  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 */
 35class 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}