1 | <?php |
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2 | /* |
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3 | Copyright (c) 2003, 2009 Danilo Segan <danilo@kvota.net>. |
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4 | Copyright (c) 2005 Nico Kaiser <nico@siriux.net> |
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5 | |
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6 | This file is part of PHP-gettext. |
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7 | |
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8 | PHP-gettext is free software; you can redistribute it and/or modify |
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9 | it under the terms of the GNU General Public License as published by |
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10 | the Free Software Foundation; either version 2 of the License, or |
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11 | (at your option) any later version. |
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12 | |
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13 | PHP-gettext is distributed in the hope that it will be useful, |
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14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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16 | GNU General Public License for more details. |
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17 | |
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18 | You should have received a copy of the GNU General Public License |
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19 | along with PHP-gettext; if not, write to the Free Software |
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20 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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21 | |
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22 | */ |
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23 | |
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24 | /** |
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25 | * Provides a simple gettext replacement that works independently from |
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26 | * the system's gettext abilities. |
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27 | * It can read MO files and use them for translating strings. |
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28 | * The files are passed to gettext_reader as a Stream (see streams.php) |
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29 | * |
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30 | * This version has the ability to cache all strings and translations to |
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31 | * speed up the string lookup. |
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32 | * While the cache is enabled by default, it can be switched off with the |
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33 | * second parameter in the constructor (e.g. whenusing very large MO files |
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34 | * that you don't want to keep in memory) |
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35 | */ |
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36 | class gettext_reader { |
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37 | //public: |
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38 | var $error = 0; // public variable that holds error code (0 if no error) |
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39 | |
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40 | //private: |
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41 | var $BYTEORDER = 0; // 0: low endian, 1: big endian |
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42 | var $STREAM = NULL; |
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43 | var $short_circuit = false; |
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44 | var $enable_cache = false; |
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45 | var $originals = NULL; // offset of original table |
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46 | var $translations = NULL; // offset of translation table |
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47 | var $pluralheader = NULL; // cache header field for plural forms |
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48 | var $total = 0; // total string count |
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49 | var $table_originals = NULL; // table for original strings (offsets) |
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50 | var $table_translations = NULL; // table for translated strings (offsets) |
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51 | var $cache_translations = NULL; // original -> translation mapping |
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52 | |
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53 | |
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54 | /* Methods */ |
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55 | |
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56 | |
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57 | /** |
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58 | * Reads a 32bit Integer from the Stream |
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59 | * |
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60 | * @access private |
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61 | * @return Integer from the Stream |
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62 | */ |
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63 | function readint() { |
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64 | if ($this->BYTEORDER == 0) { |
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65 | // low endian |
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66 | $input=unpack('V', $this->STREAM->read(4)); |
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67 | return array_shift($input); |
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68 | } else { |
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69 | // big endian |
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70 | $input=unpack('N', $this->STREAM->read(4)); |
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71 | return array_shift($input); |
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72 | } |
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73 | } |
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74 | |
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75 | function read($bytes) { |
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76 | return $this->STREAM->read($bytes); |
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77 | } |
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78 | |
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79 | /** |
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80 | * Reads an array of Integers from the Stream |
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81 | * |
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82 | * @param int count How many elements should be read |
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83 | * @return Array of Integers |
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84 | */ |
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85 | function readintarray($count) { |
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86 | if ($this->BYTEORDER == 0) { |
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87 | // low endian |
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88 | return unpack('V'.$count, $this->STREAM->read(4 * $count)); |
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89 | } else { |
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90 | // big endian |
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91 | return unpack('N'.$count, $this->STREAM->read(4 * $count)); |
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92 | } |
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93 | } |
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94 | |
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95 | /** |
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96 | * Constructor |
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97 | * |
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98 | * @param object Reader the StreamReader object |
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99 | * @param boolean enable_cache Enable or disable caching of strings (default on) |
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100 | */ |
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101 | function gettext_reader($Reader, $enable_cache = true) { |
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102 | // If there isn't a StreamReader, turn on short circuit mode. |
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103 | if (! $Reader || isset($Reader->error) ) { |
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104 | $this->short_circuit = true; |
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105 | return; |
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106 | } |
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107 | |
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108 | // Caching can be turned off |
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109 | $this->enable_cache = $enable_cache; |
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110 | |
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111 | $MAGIC1 = "\x95\x04\x12\xde"; |
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112 | $MAGIC2 = "\xde\x12\x04\x95"; |
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113 | |
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114 | $this->STREAM = $Reader; |
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115 | $magic = $this->read(4); |
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116 | if ($magic == $MAGIC1) { |
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117 | $this->BYTEORDER = 1; |
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118 | } elseif ($magic == $MAGIC2) { |
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119 | $this->BYTEORDER = 0; |
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120 | } else { |
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121 | $this->error = 1; // not MO file |
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122 | return false; |
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123 | } |
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124 | |
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125 | // FIXME: Do we care about revision? We should. |
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126 | $revision = $this->readint(); |
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127 | |
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128 | $this->total = $this->readint(); |
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129 | $this->originals = $this->readint(); |
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130 | $this->translations = $this->readint(); |
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131 | } |
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132 | |
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133 | /** |
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134 | * Loads the translation tables from the MO file into the cache |
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135 | * If caching is enabled, also loads all strings into a cache |
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136 | * to speed up translation lookups |
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137 | * |
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138 | * @access private |
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139 | */ |
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140 | function load_tables() { |
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141 | if (is_array($this->cache_translations) && |
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142 | is_array($this->table_originals) && |
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143 | is_array($this->table_translations)) |
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144 | return; |
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145 | |
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146 | /* get original and translations tables */ |
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147 | if (!is_array($this->table_originals)) { |
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148 | $this->STREAM->seekto($this->originals); |
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149 | $this->table_originals = $this->readintarray($this->total * 2); |
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150 | } |
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151 | if (!is_array($this->table_translations)) { |
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152 | $this->STREAM->seekto($this->translations); |
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153 | $this->table_translations = $this->readintarray($this->total * 2); |
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154 | } |
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155 | |
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156 | if ($this->enable_cache) { |
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157 | $this->cache_translations = array (); |
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158 | /* read all strings in the cache */ |
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159 | for ($i = 0; $i < $this->total; $i++) { |
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160 | $this->STREAM->seekto($this->table_originals[$i * 2 + 2]); |
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161 | $original = $this->STREAM->read($this->table_originals[$i * 2 + 1]); |
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162 | $this->STREAM->seekto($this->table_translations[$i * 2 + 2]); |
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163 | $translation = $this->STREAM->read($this->table_translations[$i * 2 + 1]); |
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164 | $this->cache_translations[$original] = $translation; |
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165 | } |
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166 | } |
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167 | } |
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168 | |
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169 | /** |
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170 | * Returns a string from the "originals" table |
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171 | * |
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172 | * @access private |
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173 | * @param int num Offset number of original string |
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174 | * @return string Requested string if found, otherwise '' |
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175 | */ |
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176 | function get_original_string($num) { |
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177 | $length = $this->table_originals[$num * 2 + 1]; |
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178 | $offset = $this->table_originals[$num * 2 + 2]; |
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179 | if (! $length) |
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180 | return ''; |
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181 | $this->STREAM->seekto($offset); |
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182 | $data = $this->STREAM->read($length); |
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183 | return (string)$data; |
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184 | } |
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185 | |
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186 | /** |
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187 | * Returns a string from the "translations" table |
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188 | * |
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189 | * @access private |
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190 | * @param int num Offset number of original string |
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191 | * @return string Requested string if found, otherwise '' |
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192 | */ |
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193 | function get_translation_string($num) { |
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194 | $length = $this->table_translations[$num * 2 + 1]; |
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195 | $offset = $this->table_translations[$num * 2 + 2]; |
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196 | if (! $length) |
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197 | return ''; |
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198 | $this->STREAM->seekto($offset); |
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199 | $data = $this->STREAM->read($length); |
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200 | return (string)$data; |
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201 | } |
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202 | |
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203 | /** |
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204 | * Binary search for string |
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205 | * |
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206 | * @access private |
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207 | * @param string string |
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208 | * @param int start (internally used in recursive function) |
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209 | * @param int end (internally used in recursive function) |
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210 | * @return int string number (offset in originals table) |
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211 | */ |
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212 | function find_string($string, $start = -1, $end = -1) { |
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213 | if (($start == -1) or ($end == -1)) { |
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214 | // find_string is called with only one parameter, set start end end |
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215 | $start = 0; |
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216 | $end = $this->total; |
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217 | } |
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218 | if (abs($start - $end) <= 1) { |
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219 | // We're done, now we either found the string, or it doesn't exist |
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220 | $txt = $this->get_original_string($start); |
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221 | if ($string == $txt) |
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222 | return $start; |
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223 | else |
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224 | return -1; |
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225 | } else if ($start > $end) { |
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226 | // start > end -> turn around and start over |
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227 | return $this->find_string($string, $end, $start); |
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228 | } else { |
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229 | // Divide table in two parts |
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230 | $half = (int)(($start + $end) / 2); |
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231 | $cmp = strcmp($string, $this->get_original_string($half)); |
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232 | if ($cmp == 0) |
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233 | // string is exactly in the middle => return it |
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234 | return $half; |
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235 | else if ($cmp < 0) |
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236 | // The string is in the upper half |
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237 | return $this->find_string($string, $start, $half); |
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238 | else |
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239 | // The string is in the lower half |
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240 | return $this->find_string($string, $half, $end); |
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241 | } |
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242 | } |
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243 | |
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244 | /** |
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245 | * Translates a string |
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246 | * |
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247 | * @access public |
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248 | * @param string string to be translated |
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249 | * @return string translated string (or original, if not found) |
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250 | */ |
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251 | function translate($string) { |
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252 | if ($this->short_circuit) |
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253 | return $string; |
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254 | $this->load_tables(); |
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255 | |
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256 | if ($this->enable_cache) { |
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257 | // Caching enabled, get translated string from cache |
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258 | if (array_key_exists($string, $this->cache_translations)) |
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259 | return $this->cache_translations[$string]; |
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260 | else |
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261 | return $string; |
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262 | } else { |
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263 | // Caching not enabled, try to find string |
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264 | $num = $this->find_string($string); |
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265 | if ($num == -1) |
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266 | return $string; |
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267 | else |
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268 | return $this->get_translation_string($num); |
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269 | } |
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270 | } |
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271 | |
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272 | /** |
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273 | * Sanitize plural form expression for use in PHP eval call. |
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274 | * |
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275 | * @access private |
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276 | * @return string sanitized plural form expression |
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277 | */ |
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278 | function sanitize_plural_expression($expr) { |
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279 | // Get rid of disallowed characters. |
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280 | $expr = preg_replace('@[^a-zA-Z0-9_:;\(\)\?\|\&=!<>+*/\%-]@', '', $expr); |
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281 | |
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282 | // Add parenthesis for tertiary '?' operator. |
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283 | $expr .= ';'; |
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284 | $res = ''; |
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285 | $p = 0; |
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286 | for ($i = 0; $i < strlen($expr); $i++) { |
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287 | $ch = $expr[$i]; |
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288 | switch ($ch) { |
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289 | case '?': |
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290 | $res .= ' ? ('; |
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291 | $p++; |
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292 | break; |
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293 | case ':': |
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294 | $res .= ') : ('; |
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295 | break; |
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296 | case ';': |
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297 | $res .= str_repeat( ')', $p) . ';'; |
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298 | $p = 0; |
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299 | break; |
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300 | default: |
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301 | $res .= $ch; |
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302 | } |
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303 | } |
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304 | return $res; |
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305 | } |
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306 | |
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307 | /** |
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308 | * Parse full PO header and extract only plural forms line. |
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309 | * |
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310 | * @access private |
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311 | * @return string verbatim plural form header field |
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312 | */ |
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313 | function extract_plural_forms_header_from_po_header($header) { |
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314 | if (preg_match("/(^|\n)plural-forms: ([^\n]*)\n/i", $header, $regs)) |
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315 | $expr = $regs[2]; |
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316 | else |
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317 | $expr = "nplurals=2; plural=n == 1 ? 0 : 1;"; |
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318 | return $expr; |
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319 | } |
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320 | |
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321 | /** |
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322 | * Get possible plural forms from MO header |
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323 | * |
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324 | * @access private |
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325 | * @return string plural form header |
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326 | */ |
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327 | function get_plural_forms() { |
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328 | // lets assume message number 0 is header |
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329 | // this is true, right? |
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330 | $this->load_tables(); |
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331 | |
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332 | // cache header field for plural forms |
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333 | if (! is_string($this->pluralheader)) { |
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334 | if ($this->enable_cache) { |
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335 | $header = $this->cache_translations[""]; |
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336 | } else { |
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337 | $header = $this->get_translation_string(0); |
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338 | } |
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339 | $expr = $this->extract_plural_forms_header_from_po_header($header); |
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340 | $this->pluralheader = $this->sanitize_plural_expression($expr); |
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341 | } |
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342 | return $this->pluralheader; |
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343 | } |
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344 | |
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345 | /** |
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346 | * Detects which plural form to take |
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347 | * |
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348 | * @access private |
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349 | * @param n count |
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350 | * @return int array index of the right plural form |
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351 | */ |
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352 | function select_string($n) { |
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353 | $string = $this->get_plural_forms(); |
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354 | $string = str_replace('nplurals',"\$total",$string); |
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355 | $string = str_replace("n",$n,$string); |
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356 | $string = str_replace('plural',"\$plural",$string); |
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357 | |
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358 | $total = 0; |
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359 | $plural = 0; |
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360 | |
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361 | eval("$string"); |
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362 | if ($plural >= $total) $plural = $total - 1; |
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363 | return $plural; |
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364 | } |
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365 | |
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366 | /** |
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367 | * Plural version of gettext |
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368 | * |
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369 | * @access public |
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370 | * @param string single |
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371 | * @param string plural |
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372 | * @param string number |
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373 | * @return translated plural form |
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374 | */ |
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375 | function ngettext($single, $plural, $number) { |
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376 | if ($this->short_circuit) { |
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377 | if ($number != 1) |
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378 | return $plural; |
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379 | else |
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380 | return $single; |
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381 | } |
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382 | |
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383 | // find out the appropriate form |
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384 | $select = $this->select_string($number); |
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385 | |
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386 | // this should contains all strings separated by NULLs |
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387 | $key = $single . chr(0) . $plural; |
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388 | |
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389 | |
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390 | if ($this->enable_cache) { |
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391 | if (! array_key_exists($key, $this->cache_translations)) { |
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392 | return ($number != 1) ? $plural : $single; |
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393 | } else { |
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394 | $result = $this->cache_translations[$key]; |
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395 | $list = explode(chr(0), $result); |
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396 | return $list[$select]; |
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397 | } |
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398 | } else { |
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399 | $num = $this->find_string($key); |
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400 | if ($num == -1) { |
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401 | return ($number != 1) ? $plural : $single; |
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402 | } else { |
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403 | $result = $this->get_translation_string($num); |
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404 | $list = explode(chr(0), $result); |
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405 | return $list[$select]; |
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406 | } |
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407 | } |
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408 | } |
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409 | |
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410 | function pgettext($context, $msgid) { |
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411 | $key = $context . chr(4) . $msgid; |
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412 | $ret = $this->translate($key); |
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413 | if (strpos($ret, "\004") !== FALSE) { |
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414 | return $msgid; |
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415 | } else { |
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416 | return $ret; |
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417 | } |
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418 | } |
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419 | |
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420 | function npgettext($context, $singular, $plural, $number) { |
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421 | $key = $context . chr(4) . $singular; |
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422 | $ret = $this->ngettext($key, $plural, $number); |
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423 | if (strpos($ret, "\004") !== FALSE) { |
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424 | return $singular; |
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425 | } else { |
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426 | return $ret; |
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427 | } |
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428 | |
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429 | } |
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430 | } |
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431 | |
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432 | ?> |
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