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 718 2012-10-31 00:32:02Z 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 $headers = array();
  16
  17         /**
  18          * Add entry to the PO structure
  19          *
  20          * @param array|Translation_Entry &$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          * @param array|Translation_Entry $entry
  35          * @return bool
  36          */
  37         function add_entry_or_merge($entry) {
  38                 if (is_array($entry)) {
  39                         $entry = new Translation_Entry($entry);
  40                 }
  41                 $key = $entry->key();
  42                 if (false === $key) return false;
  43                 if (isset($this->entries[$key]))
  44                         $this->entries[$key]->merge_with($entry);
  45                 else
  46                         $this->entries[$key] = &$entry;
  47                 return true;
  48         }
  49
  50         /**
  51          * Sets $header PO header to $value
  52          *
  53          * If the header already exists, it will be overwritten
  54          *
  55          * TODO: this should be out of this class, it is gettext specific
  56          *
  57          * @param string $header header name, without trailing :
  58          * @param string $value header value, without trailing \n
  59          */
  60         function set_header($header, $value) {
  61                 $this->headers[$header] = $value;
  62         }
  63
  64         /**
  65          * @param array $headers
  66          */
  67         function set_headers($headers) {
  68                 foreach($headers as $header => $value) {
  69                         $this->set_header($header, $value);
  70                 }
  71         }
  72
  73         /**
  74          * @param string $header
  75          */
  76         function get_header($header) {
  77                 return isset($this->headers[$header])? $this->headers[$header] : false;
  78         }
  79
  80         /**
  81          * @param Translation_Entry $entry
  82          */
  83         function translate_entry(&$entry) {
  84                 $key = $entry->key();
  85                 return isset($this->entries[$key])? $this->entries[$key] : false;
  86         }
  87
  88         /**
  89          * @param string $singular
  90          * @param string $context
  91          * @return string
  92          */
  93         function translate($singular, $context=null) {
  94                 $entry = new Translation_Entry(array('singular' => $singular, 'context' => $context));
  95                 $translated = $this->translate_entry($entry);
  96                 return ($translated && !empty($translated->translations))? $translated->translations[0] : $singular;
  97         }
  98
  99         /**
 100          * Given the number of items, returns the 0-based index of the plural form to use
 101          *
 102          * Here, in the base Translations class, the common logic for English is implemented:
 103          *      0 if there is one element, 1 otherwise
 104          *
 105          * This function should be overrided by the sub-classes. For example MO/PO can derive the logic
 106          * from their headers.
 107          *
 108          * @param integer $count number of items
 109          */
 110         function select_plural_form($count) {
 111                 return 1 == $count? 0 : 1;
 112         }
 113
 114         function get_plural_forms_count() {
 115                 return 2;
 116         }
 117
 118         /**
 119          * @param string $singular
 120          * @param string $plural
 121          * @param int    $count
 122          * @param string $context
 123          */
 124         function translate_plural($singular, $plural, $count, $context = null) {
 125                 $entry = new Translation_Entry(array('singular' => $singular, 'plural' => $plural, 'context' => $context));
 126                 $translated = $this->translate_entry($entry);
 127                 $index = $this->select_plural_form($count);
 128                 $total_plural_forms = $this->get_plural_forms_count();
 129                 if ($translated && 0 <= $index && $index < $total_plural_forms &&
 130                                 is_array($translated->translations) &&
 131                                 isset($translated->translations[$index]))
 132                         return $translated->translations[$index];
 133                 else
 134                         return 1 == $count? $singular : $plural;
 135         }
 136
 137         /**
 138          * Merge $other in the current object.
 139          *
 140          * @param Object &$other Another Translation object, whose translations will be merged in this one
 141          * @return void
 142          **/
 143         function merge_with(&$other) {
 144                 foreach( $other->entries as $entry ) {
 145                         $this->entries[$entry->key()] = $entry;
 146                 }
 147         }
 148
 149         function merge_originals_with(&$other) {
 150                 foreach( $other->entries as $entry ) {
 151                         if ( !isset( $this->entries[$entry->key()] ) )
 152                                 $this->entries[$entry->key()] = $entry;
 153                         else
 154                                 $this->entries[$entry->key()]->merge_with($entry);
 155                 }
 156         }
 157 }
 158
 159 class Gettext_Translations extends Translations {
 160         /**
 161          * The gettext implementation of select_plural_form.
 162          *
 163          * It lives in this class, because there are more than one descendand, which will use it and
 164          * they can't share it effectively.
 165          *
 166          * @param int $count
 167          */
 168         function gettext_select_plural_form($count) {
 169                 if (!isset($this->_gettext_select_plural_form) || is_null($this->_gettext_select_plural_form)) {
 170                         list( $nplurals, $expression ) = $this->nplurals_and_expression_from_header($this->get_header('Plural-Forms'));
 171                         $this->_nplurals = $nplurals;
 172                         $this->_gettext_select_plural_form = $this->make_plural_form_function($nplurals, $expression);
 173                 }
 174                 return call_user_func($this->_gettext_select_plural_form, $count);
 175         }
 176
 177         /**
 178          * @param string $header
 179          * @return array
 180          */
 181         function nplurals_and_expression_from_header($header) {
 182                 if (preg_match('/^\s*nplurals\s*=\s*(\d+)\s*;\s+plural\s*=\s*(.+)$/', $header, $matches)) {
 183                         $nplurals = (int)$matches[1];
 184                         $expression = trim($this->parenthesize_plural_exression($matches[2]));
 185                         return array($nplurals, $expression);
 186                 } else {
 187                         return array(2, 'n != 1');
 188                 }
 189         }
 190
 191         /**
 192          * Makes a function, which will return the right translation index, according to the
 193          * plural forms header
 194          * @param int    $nplurals
 195          * @param string $expression
 196          */
 197         function make_plural_form_function($nplurals, $expression) {
 198                 $expression = str_replace('n', '$n', $expression);
 199                 $func_body = "
 200                         \$index = (int)($expression);
 201                         return (\$index < $nplurals)? \$index : $nplurals - 1;";
 202                 return create_function('$n', $func_body);
 203         }
 204
 205         /**
 206          * Adds parentheses to the inner parts of ternary operators in
 207          * plural expressions, because PHP evaluates ternary oerators from left to right
 208          *
 209          * @param string $expression the expression without parentheses
 210          * @return string the expression with parentheses added
 211          */
 212         function parenthesize_plural_exression($expression) {
 213                 $expression .= ';';
 214                 $res = '';
 215                 $depth = 0;
 216                 for ($i = 0; $i < strlen($expression); ++$i) {
 217                         $char = $expression[$i];
 218                         switch ($char) {
 219                                 case '?':
 220                                         $res .= ' ? (';
 221                                         $depth++;
 222                                         break;
 223                                 case ':':
 224                                         $res .= ') : (';
 225                                         break;
 226                                 case ';':
 227                                         $res .= str_repeat(')', $depth) . ';';
 228                                         $depth= 0;
 229                                         break;
 230                                 default:
 231                                         $res .= $char;
 232                         }
 233                 }
 234                 return rtrim($res, ';');
 235         }
 236
 237         /**
 238          * @param string $translation
 239          * @return array
 240          */
 241         function make_headers($translation) {
 242                 $headers = array();
 243                 // sometimes \ns are used instead of real new lines
 244                 $translation = str_replace('\n', "\n", $translation);
 245                 $lines = explode("\n", $translation);
 246                 foreach($lines as $line) {
 247                         $parts = explode(':', $line, 2);
 248                         if (!isset($parts[1])) continue;
 249                         $headers[trim($parts[0])] = trim($parts[1]);
 250                 }
 251                 return $headers;
 252         }
 253
 254         /**
 255          * @param string $header
 256          * @param string $value
 257          */
 258         function set_header($header, $value) {
 259                 parent::set_header($header, $value);
 260                 if ('Plural-Forms' == $header) {
 261                         list( $nplurals, $expression ) = $this->nplurals_and_expression_from_header($this->get_header('Plural-Forms'));
 262                         $this->_nplurals = $nplurals;
 263                         $this->_gettext_select_plural_form = $this->make_plural_form_function($nplurals, $expression);
 264                 }
 265         }
 266 }
 267 endif;
 268
 269 if ( !class_exists( 'NOOP_Translations' ) ):
 270 /**
 271  * Provides the same interface as Translations, but doesn't do anything
 272  */
 273 class NOOP_Translations {
 274         var $entries = array();
 275         var $headers = array();
 276
 277         function add_entry($entry) {
 278                 return true;
 279         }
 280
 281         function set_header($header, $value) {
 282         }
 283
 284         function set_headers($headers) {
 285         }
 286
 287         function get_header($header) {
 288                 return false;
 289         }
 290
 291         function translate_entry(&$entry) {
 292                 return false;
 293         }
 294
 295         /**
 296          * @param string $singular
 297          * @param string $context
 298          */
 299         function translate($singular, $context=null) {
 300                 return $singular;
 301         }
 302
 303         function select_plural_form($count) {
 304                 return 1 == $count? 0 : 1;
 305         }
 306
 307         function get_plural_forms_count() {
 308                 return 2;
 309         }
 310
 311         /**
 312          * @param string $singular
 313          * @param string $plural
 314          * @param int    $count
 315          * @param string $context
 316          */
 317         function translate_plural($singular, $plural, $count, $context = null) {
 318                         return 1 == $count? $singular : $plural;
 319         }
 320
 321         function merge_with(&$other) {
 322         }
 323 }
 324 endif;