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 35 2009-02-16 12:54:57Z nbachiyski $
   6  * @package pomo
   7  * @subpackage translations
   8  */
   9
  10 require_once dirname(__FILE__) . '/entry.php';
  11
  12 class Translations {
  13         var $entries = array();
  14         var $headers = array();
  15
  16         /**
  17          * Add entry to the PO structure
  18          *
  19          * @param object &$entry
  20          * @return bool true on success, false if the entry doesn't have a key
  21          */
  22         function add_entry(&$entry) {
  23                 $key = $entry->key();
  24                 if (false === $key) return false;
  25                 $this->entries[$key] = &$entry;
  26                 return true;
  27         }
  28
  29         /**
  30          * Sets $header PO header to $value
  31          *
  32          * If the header already exists, it will be overwritten
  33          *
  34          * TODO: this should be out of this class, it is gettext specific
  35          *
  36          * @param string $header header name, without trailing :
  37          * @param string $value header value, without trailing \n
  38          */
  39         function set_header($header, $value) {
  40                 $this->headers[$header] = $value;
  41         }
  42
  43         function set_headers(&$headers) {
  44                 foreach($headers as $header => $value) {
  45                         $this->set_header($header, $value);
  46                 }
  47         }
  48
  49         function get_header($header) {
  50                 return isset($this->headers[$header])? $this->headers[$header] : false;
  51         }
  52
  53         function translate_entry(&$entry) {
  54                 $key = $entry->key();
  55                 return isset($this->entries[$key])? $this->entries[$key] : false;
  56         }
  57
  58         function translate($singular, $context=null) {
  59                 $entry = new Translation_Entry(array('singular' => $singular, 'context' => $context));
  60                 $translated = $this->translate_entry($entry);
  61                 return ($translated && !empty($translated->translations))? $translated->translations[0] : $singular;
  62         }
  63
  64         /**
  65          * Given the number of items, returns the 0-based index of the plural form to use
  66          *
  67          * Here, in the base Translations class, the commong logic for English is implmented:
  68          *      0 if there is one element, 1 otherwise
  69          *
  70          * This function should be overrided by the sub-classes. For example MO/PO can derive the logic
  71          * from their headers.
  72          *
  73          * @param integer $count number of items
  74          */
  75         function select_plural_form($count) {
  76                 return 1 == $count? 0 : 1;
  77         }
  78
  79         function get_plural_forms_count() {
  80                 return 2;
  81         }
  82
  83         function translate_plural($singular, $plural, $count, $context = null) {
  84                 $entry = new Translation_Entry(array('singular' => $singular, 'plural' => $plural, 'context' => $context));
  85                 $translated = $this->translate_entry($entry);
  86                 $index = $this->select_plural_form($count);
  87                 $total_plural_forms = $this->get_plural_forms_count();
  88                 if ($translated && 0 <= $index && $index < $total_plural_forms &&
  89                                 is_array($translated->translations) &&
  90                                 count($translated->translations) == $total_plural_forms)
  91                         return $translated->translations[$index];
  92                 else
  93                         return 1 == $count? $singular : $plural;
  94         }
  95
  96         /**
  97          * The gettext implmentation of select_plural_form.
  98          *
  99          * It lives in this class, because there are more than one descendand, which will use it and
 100          * they can't share it effectively.
 101          *
 102          */
 103         function gettext_select_plural_form($count) {
 104                 if (!isset($this->_gettext_select_plural_form) || is_null($this->_gettext_select_plural_form)) {
 105                         $plural_header = $this->get_header('Plural-Forms');
 106                         $this->_gettext_select_plural_form = $this->_make_gettext_select_plural_form($plural_header);
 107                 }
 108                 return call_user_func($this->_gettext_select_plural_form, $count);
 109         }
 110
 111         /**
 112          * Makes a function, which will return the right translation index, according to the
 113          * plural forms header
 114          */
 115         function _make_gettext_select_plural_form($plural_header) {
 116                 $res = create_function('$count', 'return 1 == $count? 0 : 1;');
 117                 if ($plural_header && (preg_match('/^\s*nplurals\s*=\s*(\d+)\s*;\s+plural\s*=\s*(.+)$/', $plural_header, $matches))) {
 118                         $nplurals = (int)$matches[1];
 119                         $this->_nplurals = $nplurals;
 120                         $plural_expr = trim($this->_parenthesize_plural_exression($matches[2]));
 121                         $plural_expr = str_replace('n', '$n', $plural_expr);
 122                         $func_body = "
 123                                 \$index = (int)($plural_expr);
 124                                 return (\$index < $nplurals)? \$index : $nplurals - 1;";
 125                         $res = create_function('$n', $func_body);
 126                 }
 127                 return $res;
 128         }
 129
 130         /**
 131          * Adds parantheses to the inner parts of ternary operators in
 132          * plural expressions, because PHP evaluates ternary oerators from left to right
 133          *
 134          * @param string $expression the expression without parentheses
 135          * @return string the expression with parentheses added
 136          */
 137         function _parenthesize_plural_exression($expression) {
 138                 $expression .= ';';
 139                 $res = '';
 140                 $depth = 0;
 141                 for ($i = 0; $i < strlen($expression); ++$i) {
 142                         $char = $expression[$i];
 143                         switch ($char) {
 144                                 case '?':
 145                                         $res .= ' ? (';
 146                                         $depth++;
 147                                         break;
 148                                 case ':':
 149                                         $res .= ') : (';
 150                                         break;
 151                                 case ';':
 152                                         $res .= str_repeat(')', $depth) . ';';
 153                                         $depth= 0;
 154                                         break;
 155                                 default:
 156                                         $res .= $char;
 157                         }
 158                 }
 159                 return rtrim($res, ';');
 160         }
 161
 162         /**
 163          * Merge $other in the current object.
 164          *
 165          * @param Object &$other Another Translation object, whose translations will be merged in this one
 166          * @return void
 167          **/
 168         function merge_with(&$other) {
 169                 $this->entries = array_merge($this->entries, $other->entries);
 170         }
 171 }
 172
 173 ?>