vendor/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) 2005-2015 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\StringWrapper\StringWrapperInterface;
  13
  14 /**
  15  * Utility class for handling strings of different character encodings
  16  * using available PHP extensions.
  17  *
  18  * Declared abstract, as we have no need for instantiation.
  19  */
  20 abstract class StringUtils
  21 {
  22     /**
  23      * Ordered list of registered string wrapper instances
  24      *
  25      * @var StringWrapperInterface[]
  26      */
  27     protected static $wrapperRegistry = null;
  28
  29     /**
  30      * A list of known single-byte character encodings (upper-case)
  31      *
  32      * @var string[]
  33      */
  34     protected static $singleByteEncodings = [
  35         'ASCII', '7BIT', '8BIT',
  36         'ISO-8859-1', 'ISO-8859-2', 'ISO-8859-3', 'ISO-8859-4', 'ISO-8859-5',
  37         'ISO-8859-6', 'ISO-8859-7', 'ISO-8859-8', 'ISO-8859-9', 'ISO-8859-10',
  38         'ISO-8859-11', 'ISO-8859-13', 'ISO-8859-14', 'ISO-8859-15', 'ISO-8859-16',
  39         'CP-1251', 'CP-1252',
  40         // TODO
  41     ];
  42
  43     /**
  44      * Is PCRE compiled with Unicode support?
  45      *
  46      * @var bool
  47      **/
  48     protected static $hasPcreUnicodeSupport = null;
  49
  50     /**
  51      * Get registered wrapper classes
  52      *
  53      * @return string[]
  54      */
  55     public static function getRegisteredWrappers()
  56     {
  57         if (static::$wrapperRegistry === null) {
  58             static::$wrapperRegistry = [];
  59
  60             if (extension_loaded('intl')) {
  61                 static::$wrapperRegistry[] = 'Zend\Stdlib\StringWrapper\Intl';
  62             }
  63
  64             if (extension_loaded('mbstring')) {
  65                 static::$wrapperRegistry[] = 'Zend\Stdlib\StringWrapper\MbString';
  66             }
  67
  68             if (extension_loaded('iconv')) {
  69                 static::$wrapperRegistry[] = 'Zend\Stdlib\StringWrapper\Iconv';
  70             }
  71
  72             static::$wrapperRegistry[] = 'Zend\Stdlib\StringWrapper\Native';
  73         }
  74
  75         return static::$wrapperRegistry;
  76     }
  77
  78     /**
  79      * Register a string wrapper class
  80      *
  81      * @param string $wrapper
  82      * @return void
  83      */
  84     public static function registerWrapper($wrapper)
  85     {
  86         $wrapper = (string) $wrapper;
  87         if (!in_array($wrapper, static::$wrapperRegistry, true)) {
  88             static::$wrapperRegistry[] = $wrapper;
  89         }
  90     }
  91
  92     /**
  93      * Unregister a string wrapper class
  94      *
  95      * @param string $wrapper
  96      * @return void
  97      */
  98     public static function unregisterWrapper($wrapper)
  99     {
 100         $index = array_search((string) $wrapper, static::$wrapperRegistry, true);
 101         if ($index !== false) {
 102             unset(static::$wrapperRegistry[$index]);
 103         }
 104     }
 105
 106     /**
 107      * Reset all registered wrappers so the default wrappers will be used
 108      *
 109      * @return void
 110      */
 111     public static function resetRegisteredWrappers()
 112     {
 113         static::$wrapperRegistry = null;
 114     }
 115
 116     /**
 117      * Get the first string wrapper supporting the given character encoding
 118      * and supports to convert into the given convert encoding.
 119      *
 120      * @param string      $encoding        Character encoding to support
 121      * @param string|null $convertEncoding OPTIONAL character encoding to convert in
 122      * @return StringWrapperInterface
 123      * @throws Exception\RuntimeException If no wrapper supports given character encodings
 124      */
 125     public static function getWrapper($encoding = 'UTF-8', $convertEncoding = null)
 126     {
 127         foreach (static::getRegisteredWrappers() as $wrapperClass) {
 128             if ($wrapperClass::isSupported($encoding, $convertEncoding)) {
 129                 $wrapper = new $wrapperClass($encoding, $convertEncoding);
 130                 $wrapper->setEncoding($encoding, $convertEncoding);
 131                 return $wrapper;
 132             }
 133         }
 134
 135         throw new Exception\RuntimeException(
 136             'No wrapper found supporting "' . $encoding . '"'
 137             . (($convertEncoding !== null) ? ' and "' . $convertEncoding . '"' : '')
 138         );
 139     }
 140
 141     /**
 142      * Get a list of all known single-byte character encodings
 143      *
 144      * @return string[]
 145      */
 146     public static function getSingleByteEncodings()
 147     {
 148         return static::$singleByteEncodings;
 149     }
 150
 151     /**
 152      * Check if a given encoding is a known single-byte character encoding
 153      *
 154      * @param string $encoding
 155      * @return bool
 156      */
 157     public static function isSingleByteEncoding($encoding)
 158     {
 159         return in_array(strtoupper($encoding), static::$singleByteEncodings);
 160     }
 161
 162     /**
 163      * Check if a given string is valid UTF-8 encoded
 164      *
 165      * @param string $str
 166      * @return bool
 167      */
 168     public static function isValidUtf8($str)
 169     {
 170         return is_string($str) && ($str === '' || preg_match('/^./su', $str) == 1);
 171     }
 172
 173     /**
 174      * Is PCRE compiled with Unicode support?
 175      *
 176      * @return bool
 177      */
 178     public static function hasPcreUnicodeSupport()
 179     {
 180         if (static::$hasPcreUnicodeSupport === null) {
 181             ErrorHandler::start();
 182             static::$hasPcreUnicodeSupport = defined('PREG_BAD_UTF8_OFFSET_ERROR') && preg_match('/\pL/u', 'a') == 1;
 183             ErrorHandler::stop();
 184         }
 185         return static::$hasPcreUnicodeSupport;
 186     }
 187 }