interface/modules/zend_modules/library/Zend/Stdlib/StringUtils.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\Stdlib;
  11
  12 use Zend\Stdlib\ErrorHandler;
  13 use Zend\Stdlib\StringWrapper\StringWrapperInterface;
  14
  15 /**
  16  * Utility class for handling strings of different character encodings
  17  * using available PHP extensions.
  18  *
  19  * Declared abstract, as we have no need for instantiation.
  20  */
  21 abstract class StringUtils
  22 {
  23
  24     /**
  25      * Ordered list of registered string wrapper instances
  26      *
  27      * @var StringWrapperInterface[]
  28      */
  29     protected static $wrapperRegistry = null;
  30
  31     /**
  32      * A list of known single-byte character encodings (upper-case)
  33      *
  34      * @var string[]
  35      */
  36     protected static $singleByteEncodings = array(
  37         'ASCII', '7BIT', '8BIT',
  38         'ISO-8859-1', 'ISO-8859-2', 'ISO-8859-3', 'ISO-8859-4', 'ISO-8859-5',
  39         'ISO-8859-6', 'ISO-8859-7', 'ISO-8859-8', 'ISO-8859-9', 'ISO-8859-10',
  40         'ISO-8859-11', 'ISO-8859-13', 'ISO-8859-14', 'ISO-8859-15', 'ISO-8859-16',
  41         'CP-1251', 'CP-1252',
  42         // TODO
  43     );
  44
  45     /**
  46      * Is PCRE compiled with Unicode support?
  47      *
  48      * @var bool
  49      **/
  50     protected static $hasPcreUnicodeSupport = null;
  51
  52     /**
  53      * Get registered wrapper classes
  54      *
  55      * @return string[]
  56      */
  57     public static function getRegisteredWrappers()
  58     {
  59         if (static::$wrapperRegistry === null) {
  60             static::$wrapperRegistry = array();
  61
  62             if (extension_loaded('intl')) {
  63                 static::$wrapperRegistry[] = 'Zend\Stdlib\StringWrapper\Intl';
  64             }
  65
  66             if (extension_loaded('mbstring')) {
  67                 static::$wrapperRegistry[] = 'Zend\Stdlib\StringWrapper\MbString';
  68             }
  69
  70             if (extension_loaded('iconv')) {
  71                 static::$wrapperRegistry[] = 'Zend\Stdlib\StringWrapper\Iconv';
  72             }
  73
  74             static::$wrapperRegistry[] = 'Zend\Stdlib\StringWrapper\Native';
  75         }
  76
  77         return static::$wrapperRegistry;
  78     }
  79
  80     /**
  81      * Register a string wrapper class
  82      *
  83      * @param string $wrapper
  84      * @return void
  85      */
  86     public static function registerWrapper($wrapper)
  87     {
  88         $wrapper = (string) $wrapper;
  89         if (!in_array($wrapper, static::$wrapperRegistry, true)) {
  90             static::$wrapperRegistry[] = $wrapper;
  91         }
  92     }
  93
  94     /**
  95      * Unregister a string wrapper class
  96      *
  97      * @param string $wrapper
  98      * @return void
  99      */
 100     public static function unregisterWrapper($wrapper)
 101     {
 102         $index = array_search((string) $wrapper, static::$wrapperRegistry, true);
 103         if ($index !== false) {
 104             unset(static::$wrapperRegistry[$index]);
 105         }
 106     }
 107
 108     /**
 109      * Reset all registered wrappers so the default wrappers will be used
 110      *
 111      * @return void
 112      */
 113     public static function resetRegisteredWrappers()
 114     {
 115         static::$wrapperRegistry = null;
 116     }
 117
 118     /**
 119      * Get the first string wrapper supporting the given character encoding
 120      * and supports to convert into the given convert encoding.
 121      *
 122      * @param string      $encoding        Character encoding to support
 123      * @param string|null $convertEncoding OPTIONAL character encoding to convert in
 124      * @return StringWrapperInterface
 125      * @throws Exception\RuntimeException If no wrapper supports given character encodings
 126      */
 127     public static function getWrapper($encoding = 'UTF-8', $convertEncoding = null)
 128     {
 129         foreach (static::getRegisteredWrappers() as $wrapperClass) {
 130             if ($wrapperClass::isSupported($encoding, $convertEncoding)) {
 131                 $wrapper = new $wrapperClass($encoding, $convertEncoding);
 132                 $wrapper->setEncoding($encoding, $convertEncoding);
 133                 return $wrapper;
 134             }
 135         }
 136
 137         throw new Exception\RuntimeException(
 138             'No wrapper found supporting "' . $encoding . '"'
 139             . (($convertEncoding !== null) ? ' and "' . $convertEncoding . '"' : '')
 140         );
 141     }
 142
 143     /**
 144      * Get a list of all known single-byte character encodings
 145      *
 146      * @return string[]
 147      */
 148     public static function getSingleByteEncodings()
 149     {
 150         return static::$singleByteEncodings;
 151     }
 152
 153     /**
 154      * Check if a given encoding is a known single-byte character encoding
 155      *
 156      * @param string $encoding
 157      * @return bool
 158      */
 159     public static function isSingleByteEncoding($encoding)
 160     {
 161         return in_array(strtoupper($encoding), static::$singleByteEncodings);
 162     }
 163
 164     /**
 165      * Check if a given string is valid UTF-8 encoded
 166      *
 167      * @param string $str
 168      * @return bool
 169      */
 170     public static function isValidUtf8($str)
 171     {
 172         return is_string($str) && ($str === '' || preg_match('/^./su', $str) == 1);
 173     }
 174
 175     /**
 176      * Is PCRE compiled with Unicode support?
 177      *
 178      * @return bool
 179      */
 180     public static function hasPcreUnicodeSupport()
 181     {
 182         if (static::$hasPcreUnicodeSupport === null) {
 183             ErrorHandler::start();
 184             static::$hasPcreUnicodeSupport = defined('PREG_BAD_UTF8_OFFSET_ERROR') && preg_match('/\pL/u', 'a') == 1;
 185             ErrorHandler::stop();
 186         }
 187         return static::$hasPcreUnicodeSupport;
 188     }
 189 }