wp-includes/pomo/translations.php

   1 <?php
   2 /**
   3  * Class for a set of entries for translation and their associated headers
   4  *
   5  * @version $Id: translations.php 406 2010-02-07 11:10:24Z nbachiyski $
   6  * @package pomo
   7  * @subpackage translations
   8  */
   9
  10 require_once dirname(__FILE__) . '/entry.php';
  11
  12 if ( !class_exists( 'Translations' ) ):
  13 class Translations {
  14         var $entries = array();
  15         var $headers = array();
  16
  17         /**
  18          * Add entry to the PO structure
  19          *
  20          * @param object &$entry
  21          * @return bool true on success, false if the entry doesn't have a key
  22          */
  23         function add_entry($entry) {
  24                 if (is_array($entry)) {
  25                         $entry = new Translation_Entry($entry);
  26                 }
  27                 $key = $entry->key();
  28                 if (false === $key) return false;
  29                 $this->entries[$key] = &$entry;
  30                 return true;
  31         }
  32
  33         /**
  34          * Sets $header PO header to $value
  35          *
  36          * If the header already exists, it will be overwritten
  37          *
  38          * TODO: this should be out of this class, it is gettext specific
  39          *
  40          * @param string $header header name, without trailing :
  41          * @param string $value header value, without trailing \n
  42          */
  43         function set_header($header, $value) {
  44                 $this->headers[$header] = $value;
  45         }
  46
  47         function set_headers(&$headers) {
  48                 foreach($headers as $header => $value) {
  49                         $this->set_header($header, $value);
  50                 }
  51         }
  52
  53         function get_header($header) {
  54                 return isset($this->headers[$header])? $this->headers[$header] : false;
  55         }
  56
  57         function translate_entry(&$entry) {
  58                 $key = $entry->key();
  59                 return isset($this->entries[$key])? $this->entries[$key] : false;
  60         }
  61
  62         function translate($singular, $context=null) {
  63                 $entry = new Translation_Entry(array('singular' => $singular, 'context' => $context));
  64                 $translated = $this->translate_entry($entry);
  65                 return ($translated && !empty($translated->translations))? $translated->translations[0] : $singular;
  66         }
  67
  68         /**
  69          * Given the number of items, returns the 0-based index of the plural form to use
  70          *
  71          * Here, in the base Translations class, the commong logic for English is implmented:
  72          *      0 if there is one element, 1 otherwise
  73          *
  74          * This function should be overrided by the sub-classes. For example MO/PO can derive the logic
  75          * from their headers.
  76          *
  77          * @param integer $count number of items
  78          */
  79         function select_plural_form($count) {
  80                 return 1 == $count? 0 : 1;
  81         }
  82
  83         function get_plural_forms_count() {
  84                 return 2;
  85         }
  86
  87         function translate_plural($singular, $plural, $count, $context = null) {
  88                 $entry = new Translation_Entry(array('singular' => $singular, 'plural' => $plural, 'context' => $context));
  89                 $translated = $this->translate_entry($entry);
  90                 $index = $this->select_plural_form($count);
  91                 $total_plural_forms = $this->get_plural_forms_count();
  92                 if ($translated && 0 <= $index && $index < $total_plural_forms &&
  93                                 is_array($translated->translations) &&
  94                                 isset($translated->translations[$index]))
  95                         return $translated->translations[$index];
  96                 else
  97                         return 1 == $count? $singular : $plural;
  98         }
  99
 100         /**
 101          * Merge $other in the current object.
 102          *
 103          * @param Object &$other Another Translation object, whose translations will be merged in this one
 104          * @return void
 105          **/
 106         function merge_with(&$other) {
 107                 foreach( $other->entries as $entry ) {
 108                         $this->entries[$entry->key()] = $entry;
 109                 }
 110         }
 111 }
 112
 113 class Gettext_Translations extends Translations {
 114         /**
 115          * The gettext implmentation of select_plural_form.
 116          *
 117          * It lives in this class, because there are more than one descendand, which will use it and
 118          * they can't share it effectively.
 119          *
 120          */
 121         function gettext_select_plural_form($count) {
 122                 if (!isset($this->_gettext_select_plural_form) || is_null($this->_gettext_select_plural_form)) {
 123                         list( $nplurals, $expression ) = $this->nplurals_and_expression_from_header($this->get_header('Plural-Forms'));
 124                         $this->_nplurals = $nplurals;
 125                         $this->_gettext_select_plural_form = $this->make_plural_form_function($nplurals, $expression);
 126                 }
 127                 return call_user_func($this->_gettext_select_plural_form, $count);
 128         }
 129
 130         function nplurals_and_expression_from_header($header) {
 131                 if (preg_match('/^\s*nplurals\s*=\s*(\d+)\s*;\s+plural\s*=\s*(.+)$/', $header, $matches)) {
 132                         $nplurals = (int)$matches[1];
 133                         $expression = trim($this->parenthesize_plural_exression($matches[2]));
 134                         return array($nplurals, $expression);
 135                 } else {
 136                         return array(2, 'n != 1');
 137                 }
 138         }
 139
 140         /**
 141          * Makes a function, which will return the right translation index, according to the
 142          * plural forms header
 143          */
 144         function make_plural_form_function($nplurals, $expression) {
 145                 $expression = str_replace('n', '$n', $expression);
 146                 $func_body = "
 147                         \$index = (int)($expression);
 148                         return (\$index < $nplurals)? \$index : $nplurals - 1;";
 149                 return create_function('$n', $func_body);
 150         }
 151
 152         /**
 153          * Adds parantheses to the inner parts of ternary operators in
 154          * plural expressions, because PHP evaluates ternary oerators from left to right
 155          *
 156          * @param string $expression the expression without parentheses
 157          * @return string the expression with parentheses added
 158          */
 159         function parenthesize_plural_exression($expression) {
 160                 $expression .= ';';
 161                 $res = '';
 162                 $depth = 0;
 163                 for ($i = 0; $i < strlen($expression); ++$i) {
 164                         $char = $expression[$i];
 165                         switch ($char) {
 166                                 case '?':
 167                                         $res .= ' ? (';
 168                                         $depth++;
 169                                         break;
 170                                 case ':':
 171                                         $res .= ') : (';
 172                                         break;
 173                                 case ';':
 174                                         $res .= str_repeat(')', $depth) . ';';
 175                                         $depth= 0;
 176                                         break;
 177                                 default:
 178                                         $res .= $char;
 179                         }
 180                 }
 181                 return rtrim($res, ';');
 182         }
 183
 184         function make_headers($translation) {
 185                 $headers = array();
 186                 // sometimes \ns are used instead of real new lines
 187                 $translation = str_replace('\n', "\n", $translation);
 188                 $lines = explode("\n", $translation);
 189                 foreach($lines as $line) {
 190                         $parts = explode(':', $line, 2);
 191                         if (!isset($parts[1])) continue;
 192                         $headers[trim($parts[0])] = trim($parts[1]);
 193                 }
 194                 return $headers;
 195         }
 196
 197         function set_header($header, $value) {
 198                 parent::set_header($header, $value);
 199                 if ('Plural-Forms' == $header) {
 200                         list( $nplurals, $expression ) = $this->nplurals_and_expression_from_header($this->get_header('Plural-Forms'));
 201                         $this->_nplurals = $nplurals;
 202                         $this->_gettext_select_plural_form = $this->make_plural_form_function($nplurals, $expression);
 203                 }
 204         }
 205 }
 206 endif;
 207
 208 if ( !class_exists( 'NOOP_Translations' ) ):
 209 /**
 210  * Provides the same interface as Translations, but doesn't do anything
 211  */
 212 class NOOP_Translations {
 213         var $entries = array();
 214         var $headers = array();
 215
 216         function add_entry($entry) {
 217                 return true;
 218         }
 219
 220         function set_header($header, $value) {
 221         }
 222
 223         function set_headers(&$headers) {
 224         }
 225
 226         function get_header($header) {
 227                 return false;
 228         }
 229
 230         function translate_entry(&$entry) {
 231                 return false;
 232         }
 233
 234         function translate($singular, $context=null) {
 235                 return $singular;
 236         }
 237
 238         function select_plural_form($count) {
 239                 return 1 == $count? 0 : 1;
 240         }
 241
 242         function get_plural_forms_count() {
 243                 return 2;
 244         }
 245
 246         function translate_plural($singular, $plural, $count, $context = null) {
 247                         return 1 == $count? $singular : $plural;
 248         }
 249
 250         function merge_with(&$other) {
 251         }
 252 }
 253 endif;