inc/Utf8/Conversion.php

   1 <?php
   2
   3 namespace dokuwiki\Utf8;
   4
   5 /**
   6  * Methods to convert from and to UTF-8 strings
   7  */
   8 class Conversion
   9 {
  10
  11     /**
  12      * Encodes UTF-8 characters to HTML entities
  13      *
  14      * @author Tom N Harris <tnharris@whoopdedo.org>
  15      * @author <vpribish at shopping dot com>
  16      * @link   http://php.net/manual/en/function.utf8-decode.php
  17      *
  18      * @param string $str
  19      * @param bool $all Encode non-utf8 char to HTML as well
  20      * @return string
  21      */
  22     public static function toHtml($str, $all = false)
  23     {
  24         $ret = '';
  25         foreach (Unicode::fromUtf8($str) as $cp) {
  26             if ($cp < 0x80 && !$all) {
  27                 $ret .= chr($cp);
  28             } elseif ($cp < 0x100) {
  29                 $ret .= "&#$cp;";
  30             } else {
  31                 $ret .= '&#x' . dechex($cp) . ';';
  32             }
  33         }
  34         return $ret;
  35     }
  36
  37     /**
  38      * Decodes HTML entities to UTF-8 characters
  39      *
  40      * Convert any &#..; entity to a codepoint,
  41      * The entities flag defaults to only decoding numeric entities.
  42      * Pass HTML_ENTITIES and named entities, including &amp; &lt; etc.
  43      * are handled as well. Avoids the problem that would occur if you
  44      * had to decode "&amp;#38;&#38;amp;#38;"
  45      *
  46      * unhtmlspecialchars(\dokuwiki\Utf8\Conversion::fromHtml($s)) -> "&#38;&#38;"
  47      * \dokuwiki\Utf8\Conversion::fromHtml(unhtmlspecialchars($s)) -> "&&amp#38;"
  48      * what it should be                   -> "&#38;&amp#38;"
  49      *
  50      * @author Tom N Harris <tnharris@whoopdedo.org>
  51      *
  52      * @param  string $str UTF-8 encoded string
  53      * @param  boolean $entities decode name entities in addtition to numeric ones
  54      * @return string  UTF-8 encoded string with numeric (and named) entities replaced.
  55      */
  56     public static function fromHtml($str, $entities = false)
  57     {
  58         if (!$entities) {
  59             return preg_replace_callback(
  60                 '/(&#([Xx])?([0-9A-Za-z]+);)/m',
  61                 [__CLASS__, 'decodeNumericEntity'],
  62                 $str
  63             );
  64         }
  65
  66         return preg_replace_callback(
  67             '/&(#)?([Xx])?([0-9A-Za-z]+);/m',
  68             [__CLASS__, 'decodeAnyEntity'],
  69             $str
  70         );
  71     }
  72
  73     /**
  74      * Decodes any HTML entity to it's correct UTF-8 char equivalent
  75      *
  76      * @param string $ent An entity
  77      * @return string
  78      */
  79     protected static function decodeAnyEntity($ent)
  80     {
  81         // create the named entity lookup table
  82         static $table = null;
  83         if ($table === null) {
  84             $table = get_html_translation_table(HTML_ENTITIES);
  85             $table = array_flip($table);
  86             $table = array_map(
  87                 static function ($c) {
  88                     return Unicode::toUtf8(array(ord($c)));
  89                 },
  90                 $table
  91             );
  92         }
  93
  94         if ($ent[1] === '#') {
  95             return self::decodeNumericEntity($ent);
  96         }
  97
  98         if (array_key_exists($ent[0], $table)) {
  99             return $table[$ent[0]];
 100         }
 101
 102         return $ent[0];
 103     }
 104
 105     /**
 106      * Decodes numeric HTML entities to their correct UTF-8 characters
 107      *
 108      * @param $ent string A numeric entity
 109      * @return string|false
 110      */
 111     protected static function decodeNumericEntity($ent)
 112     {
 113         switch ($ent[2]) {
 114             case 'X':
 115             case 'x':
 116                 $cp = hexdec($ent[3]);
 117                 break;
 118             default:
 119                 $cp = intval($ent[3]);
 120                 break;
 121         }
 122         return Unicode::toUtf8(array($cp));
 123     }
 124
 125     /**
 126      * UTF-8 to UTF-16BE conversion.
 127      *
 128      * Maybe really UCS-2 without mb_string due to utf8_to_unicode limits
 129      *
 130      * @param string $str
 131      * @param bool $bom
 132      * @return string
 133      */
 134     public static function toUtf16be($str, $bom = false)
 135     {
 136         $out = $bom ? "\xFE\xFF" : '';
 137         if (UTF8_MBSTRING) {
 138             return $out . mb_convert_encoding($str, 'UTF-16BE', 'UTF-8');
 139         }
 140
 141         $uni = Unicode::fromUtf8($str);
 142         foreach ($uni as $cp) {
 143             $out .= pack('n', $cp);
 144         }
 145         return $out;
 146     }
 147
 148     /**
 149      * UTF-8 to UTF-16BE conversion.
 150      *
 151      * Maybe really UCS-2 without mb_string due to utf8_to_unicode limits
 152      *
 153      * @param string $str
 154      * @return false|string
 155      */
 156     public static function fromUtf16be($str)
 157     {
 158         $uni = unpack('n*', $str);
 159         return Unicode::toUtf8($uni);
 160     }
 161
 162 }