source: trunk/www.guidonia.net/wp/wp-includes/pomo/translations.php@ 44

<?php
/**
 * Class for a set of entries for translation and their associated headers
 *
 * @version $Id: translations.php 114 2009-05-11 17:30:38Z nbachiyski $
 * @package pomo
 * @subpackage translations
 */

require_once dirname(__FILE__) . '/entry.php';

class Translations {
        var $entries = array();
        var $headers = array();

        /**
         * Add entry to the PO structure
         *
         * @param object &$entry
         * @return bool true on success, false if the entry doesn't have a key
         */
        function add_entry($entry) {
                if (is_array($entry)) {
                        $entry = new Translation_Entry($entry);
                }
                $key = $entry->key();
                if (false === $key) return false;
                $this->entries[$key] = $entry;
                return true;
        }

        /**
         * Sets $header PO header to $value
         *
         * If the header already exists, it will be overwritten
         *
         * TODO: this should be out of this class, it is gettext specific
         *
         * @param string $header header name, without trailing :
         * @param string $value header value, without trailing \n
         */
        function set_header($header, $value) {
                $this->headers[$header] = $value;
        }

        function set_headers(&$headers) {
                foreach($headers as $header => $value) {
                        $this->set_header($header, $value);
                }
        }

        function get_header($header) {
                return isset($this->headers[$header])? $this->headers[$header] : false;
        }

        function translate_entry(&$entry) {
                $key = $entry->key();
                return isset($this->entries[$key])? $this->entries[$key] : false;
        }

        function translate($singular, $context=null) {
                $entry = new Translation_Entry(array('singular' => $singular, 'context' => $context));
                $translated = $this->translate_entry($entry);
                return ($translated && !empty($translated->translations))? $translated->translations[0] : $singular;
        }

        /**
         * Given the number of items, returns the 0-based index of the plural form to use
         *
         * Here, in the base Translations class, the commong logic for English is implmented:
         *      0 if there is one element, 1 otherwise
         *
         * This function should be overrided by the sub-classes. For example MO/PO can derive the logic
         * from their headers.
         *
         * @param integer $count number of items
         */
        function select_plural_form($count) {
                return 1 == $count? 0 : 1;
        }

        function get_plural_forms_count() {
                return 2;
        }

        function translate_plural($singular, $plural, $count, $context = null) {
                $entry = new Translation_Entry(array('singular' => $singular, 'plural' => $plural, 'context' => $context));
                $translated = $this->translate_entry($entry);
                $index = $this->select_plural_form($count);
                $total_plural_forms = $this->get_plural_forms_count();
                if ($translated && 0 <= $index && $index < $total_plural_forms &&
                                is_array($translated->translations) &&
                                isset($translated->translations[$index]))
                        return $translated->translations[$index];
                else
                        return 1 == $count? $singular : $plural;
        }

        /**
         * Merge $other in the current object.
         *
         * @param Object &$other Another Translation object, whose translations will be merged in this one
         * @return void
         **/
        function merge_with(&$other) {
                $this->entries = array_merge($this->entries, $other->entries);
        }
}

class Gettext_Translations extends Translations {
        /**
         * The gettext implmentation of select_plural_form.
         *
         * It lives in this class, because there are more than one descendand, which will use it and
         * they can't share it effectively.
         *
         */
        function gettext_select_plural_form($count) {
                if (!isset($this->_gettext_select_plural_form) || is_null($this->_gettext_select_plural_form)) {
                        $plural_header = $this->get_header('Plural-Forms');
                        $this->_gettext_select_plural_form = $this->_make_gettext_select_plural_form($plural_header);
                }
                return call_user_func($this->_gettext_select_plural_form, $count);
        }

        /**
         * Makes a function, which will return the right translation index, according to the
         * plural forms header
         */
        function _make_gettext_select_plural_form($plural_header) {
                $res = create_function('$count', 'return 1 == $count? 0 : 1;');
                if ($plural_header && (preg_match('/^\s*nplurals\s*=\s*(\d+)\s*;\s+plural\s*=\s*(.+)$/', $plural_header, $matches))) {
                        $nplurals = (int)$matches[1];
                        $this->_nplurals = $nplurals;
                        $plural_expr = trim($this->_parenthesize_plural_exression($matches[2]));
                        $plural_expr = str_replace('n', '$n', $plural_expr);
                        $func_body = "
                                \$index = (int)($plural_expr);
                                return (\$index < $nplurals)? \$index : $nplurals - 1;";
                        $res = create_function('$n', $func_body);
                }
                return $res;
        }

        /**
         * Adds parantheses to the inner parts of ternary operators in
         * plural expressions, because PHP evaluates ternary oerators from left to right
         * 
         * @param string $expression the expression without parentheses
         * @return string the expression with parentheses added
         */
        function _parenthesize_plural_exression($expression) {
                $expression .= ';';
                $res = '';
                $depth = 0;
                for ($i = 0; $i < strlen($expression); ++$i) {
                        $char = $expression[$i];
                        switch ($char) {
                                case '?':
                                        $res .= ' ? (';
                                        $depth++;
                                        break;
                                case ':':
                                        $res .= ') : (';
                                        break;
                                case ';':
                                        $res .= str_repeat(')', $depth) . ';';
                                        $depth= 0;
                                        break;
                                default:
                                        $res .= $char;
                        }
                }
                return rtrim($res, ';');
        }
        
        function make_headers($translation) {
                $headers = array();
                // sometimes \ns are used instead of real new lines
                $translation = str_replace('\n', "\n", $translation);
                $lines = explode("\n", $translation);
                foreach($lines as $line) {
                        $parts = explode(':', $line, 2);
                        if (!isset($parts[1])) continue;
                        $headers[trim($parts[0])] = trim($parts[1]);
                }
                return $headers;
        }

        function set_header($header, $value) {
                parent::set_header($header, $value);
                if ('Plural-Forms' == $header)
                        $this->_gettext_select_plural_form = $this->_make_gettext_select_plural_form($value);
        }

        
}

?>