i18n.module

<?php
// $Id$

/**
 * @file
 * Internationalization (i18n) module
 *
 * @author Jose A. Reyero, 2004
 *
 */

// Some constants. Language support modes for content
define('LANGUAGE_SUPPORT_NONE', 0);
define('LANGUAGE_SUPPORT_NORMAL', 1);
define('LANGUAGE_SUPPORT_EXTENDED', 2);

/**
 * Module initialization
 * 
 * Get language from path if exists and Initialize i18n system
 */

/**
 * This one expects to be called first from common.inc
 */
function i18n_get_lang($setlanguage = NULL) {
  static $i18n_language;
  //see if the language is already set.
  if ($setlanguage) {
    $i18n_language = $setlanguage;
  } elseif ($i18n_language) {
    return $i18n_language;
  } else {
    _i18n_init();
    return $i18n_language = _i18n_get_lang();
  }
}

/**
 * Minimum initialization
 */
function _i18n_init(){
  global $i18n_langpath;
  $path = _i18n_get_original_path();
  $i18n_langpath = i18n_get_lang_prefix($path);
}  

/**
 * Language block
 * 
 * This is a simple language switcher which knows nothing about translations
 */
function i18n_block($op = 'list', $delta = 0) {
  if ($op == 'list') {
    $blocks[0]['info'] = t('Language switcher');
  }
  elseif($op == 'view') {
    $blocks['subject'] = t('Languages');
    $query = drupal_query_string_encode($_GET, array('q'));
    $blocks['content'] = theme('item_list', i18n_get_links($_GET['q'], empty($query) ? NULL : $query));
  }
  return $blocks;
}

/**
 * Implementation of hook_init()
 * 
 * May do a redirect from home page for not to get wrong versions in cache
 * Warning: when in bootstrap mode, this may be called before i18n_get_lang()
 */
function i18n_init(){
  global $i18n_langpath;
  $lang = i18n_get_lang();
  $path = _i18n_get_original_path();
  // Init selection mode
  i18n_selection_mode(variable_get('i18n_selection_mode', 'simple'));
  // Multi tables, for backwards compatibility and experimentation
  _i18n_set_db_prefix($lang);

  if ($path == '') { // Main page
    // Check for update or cron scripts to disable rewriting and redirection
    if(preg_match('|/(?!index\.php)\w+\.php|', request_uri())){
      i18n_selection_mode('off');
    } elseif ($lang != i18n_default_language()) {
      // Redirect to main page in $lang when it's not default language.
      _i18n_goto($lang);
    } else {
      $_GET['q'] = i18n_frontpage($lang);
    } 
  } elseif ($lang == $path) { // When path is only language code
    $_GET['q'] = i18n_frontpage($lang);
  }
  elseif ($i18n_langpath) {
    //search alias with and without lang and remove lang.
    $_GET['q'] = i18n_get_normal_path($path);
  }
  // If not in bootstrap, variable init
  if(!_i18n_is_bootstrap()){
    //include drupal_get_path('module', 'i18n').'/i18n.inc';
    i18n_variable_init();    
  }  
}

/**
 * Implementation of hook_help().
 */
function i18n_help($section = 'admin/help#i18n' ) {
  switch ($section) {
    case 'admin/help#i18n' :
      $output = '<p>'.t('This module provides support for multilingual content in Drupal sites:').'</p>';
      $output .= '<ul>';
      $output .= '<li>'.t('Translation of the user interface for anonymous users (combined with locale)').'</li>';
      $output .= '<li>'.t('Multi-language for content. Adds a language field for nodes and taxonomy vocabularies and terms').'</li>';
      $output .= '<li>'.t('Browser language detection').'</li>';
      $output .= '<li>'.t('Keeps the language setting accross consecutive requests using URL rewriting').'</li>';
      $output .= '<li>'.t('Provides a block for language selection and two theme functions: <i>i18n_flags</i> and <i>i18n_links</i>').'</li>';
      $output .= '<li>'.t('Support for long locale names').'</li>';
      $output .= '<li>'.t('Multilingual menu items').'</li>';      
      $output .= '</ul>';
      $output .= '<p>'. t('For more information please read the <a href="@i18n">on-line help pages</a>.', array('@i18n' =>'http://drupal.org/node/31631')) .'</p>';
      return $output;
    case 'admin/settings/i18n':
      $output .= '<p>'.t('To enable multilingual support for specific content types go to !configure_content_types.', array('!configure_content_types' => l(t('configure content types'), 'admin/content/types'), )).'</p>';
      return $output;
  }
}

/**
 * Implementation of hook_menu().
 * Modify rewriting conditions when viewing specific nodes
 */
function i18n_menu($may_cache) {
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/settings/i18n',
      'title' => t('Multilingual system'),
      'description' => t('Configure multilingual content and translation.'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('i18n_admin_settings'),
      'access' => user_access('administer site configuration'),
      );
    $items[] = array(
      'path' => 'admin/settings/i18n/main',
      'title' => t('Internationalization'),
      'type' => MENU_DEFAULT_LOCAL_TASK
      );
    $items[] = array('path' => 'admin/settings/i18n/language',
      'title' => t('Manage languages'),
      'description' => t('Configure languages.'),
      'callback' => 'locale_admin_manage',
      'type' => MENU_LOCAL_TASK);  
  } else {   
    if (arg(0) == 'node') {
      if(isset($_POST['language']) && $_POST['language']) {
        $language = $_POST['language'];
      } elseif( is_numeric(arg(1)) && $node = node_load(arg(1)) ) {
        // Node language when loading specific nodes
        $language = $node->language;
      }
      if($language) i18n_selection_mode('node', db_escape_string($language));
    } elseif(arg(0) == 'admin' && user_access('administer all languages')) {
      // No restrictions for administration pages
      i18n_selection_mode('off');
    }
  }

  return $items;
}

/**
 * Implementation of hook_nodeapi().
 */
function i18n_nodeapi(&$node, $op, $teaser = NULL, $page = NULL) {
  if (variable_get("i18n_node_$node->type", 0)) {
      switch ($op) {
      case 'load':
        return db_fetch_array(db_query("SELECT trid, language, status AS i18n_status FROM {i18n_node} WHERE nid=%d", $node->nid));
      case 'insert':
      case 'update':
        db_query("DELETE FROM {i18n_node} WHERE nid=%d",$node->nid);
        if($node->language){
          db_query("INSERT INTO {i18n_node} (nid, trid, language, status) VALUES(%d, '%d', '%s', '%d')", $node->nid, $node->trid, $node->language, $node->i18n_status);
        }
        // Handle menu items. Fixes duplication issue and language for menu items which happens when editing nodes in languages other than current.
        if (isset($node->menu) && !$node->menu['delete'] && $node->menu['title']) {
          $item = $node->menu;
          $item['path'] = ($item['path']) ? $item['path'] : "node/$node->nid";

          if ($item['mid']) {
            // Update menu item 
            db_query("UPDATE {menu} SET pid = %d, path = '%s', title = '%s', description = '%s', weight = %d, type = %d, language = '%s' WHERE mid = %d", $item['pid'], $item['path'], $item['title'], $item['description'], $item['weight'], $item['type'], $item['mid'], $node->language);
            drupal_set_message(t('The menu item %title has been updated with node language.', array('%title' => $item['title'])));
          } elseif(SAVED_NEW == menu_save_item($item)) {
            // Creating new menu item with node language
            db_query("UPDATE {menu} SET language = '%s' WHERE mid = %d", $node->language, $item['mid']);
            drupal_set_message(t('The menu item %title has been added with node language.',  array('%title' => $item['title'])));         
          }
          menu_rebuild();
          unset($node->menu); // Avoid further processing by menu module
        }
        break;
      case 'delete': 
        db_query('DELETE FROM {i18n_node} WHERE nid=%d', $node->nid);
        break;
      }
  }   
}


/**
 * Implementation of hook_taxonomy
 * 
 * $edit parameter may be an array or an object !!
 */
function i18n_taxonomy($op, $type, $edit = NULL) {
  $edit = (array)$edit;
  switch ("$type/$op") {
    case 'term/insert':
    case 'term/update':
        $language = isset($edit['language']) ? $edit['language'] : '';
      db_query("UPDATE {term_data} SET language='%s' WHERE tid=%d", $language, $edit['tid']);    
      break;
    case 'vocabulary/insert':    
    case 'vocabulary/update':
        $language = isset($edit['language']) ? $edit['language'] : '';
        db_query("UPDATE {vocabulary} SET language='%s' WHERE vid=%d", $language, $edit['vid']);    
        if ($language && $op == 'update') {
          db_query("UPDATE {term_data} SET language='%s' WHERE vid=%d", $edit['language'], $edit['vid']);
          drupal_set_message(t('Reset language for all terms.'));
        }
        break;
  }
}

/**
 * Implementation of hook_user()
 * 
 * Switch to user's language after login
 */
function i18n_user($op, &$edit, &$account, $category = NULL) {
  if($op == 'login' && $account->language) {
    $_SESSION['language'] = $account->language;
    i18n_get_lang($account->language);
  }
}

/**
 * Form builder function.
 * 
 * Some options have been removed from previous versions:
 * - Languages are now taken from locale module unless defined in settings file
 * - Language dependent tables are authomatically used if defined in settings file
 */
function i18n_admin_settings() {
  // Check languages
  $languages = variable_get('i18n_languages', array());
  if (!count($languages) || ! count($languages['active']) > 1 ) {
    drupal_set_message(t('No languages enabled. Visit the !locale_admin page to set up your languages.', array('!locale_admin' => l(t('Manage languages'), 'admin/settings/locale/'))), 'error');
  }
  $form['i18n_browser'] = array(
    '#type' => 'radios',
    '#title' => t('Browser language detection'),
    '#default_value' => variable_get('i18n_browser', 0),
    '#options' => array(t('Disabled'), t('Enabled' )),
    '#description' => t("User browser language for home page and links without language prefix."),
  );
  
  // Language icons
  $form['icons'] = array(
    '#type' => 'fieldset',
    '#title' => t('Language icons settings'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
  );
  $form['icons']['i18n_icon_path'] = array(
    '#type' => 'textfield',
    '#title' => t('Language icons path'),
    '#default_value' => variable_get('i18n_icon_path', drupal_get_path('module', 'i18n').'/flags/*.png'),
    '#size' => 70,
    '#maxlength' => 180,
    '#description' => t('Path for language icons, relative to Drupal installation. \'*\' is a placeholder for language code.'),
  );
  $form['icons']['i18n_icon_size'] = array(
    '#type' => 'textfield',
    '#title' => t('Language icons size'),
    '#default_value' => variable_get('i18n_icon_size', '16x12'),
    '#size' => 10,
    '#maxlength' => 10,
    '#description' => t('Image size for language icons, in the form "width x height".'),
  );

  // Advanced options
  $form['advanced'] = array(
    '#type' => 'fieldset',
    '#title' => t('Advanced settings'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );
  $form['advanced']['i18n_selection_mode'] = array(
    '#type' => 'radios',
    '#title' => t('Content selection mode'),
    '#default_value' => variable_get('i18n_selection_mode', 'simple'),
    '#options' => _i18n_selection_mode(),
    '#description' => t('Determines which content to show depending on language.'),
  );
    
  return system_settings_form($form);
}

/**
 * Simple i18n API
 */

/**
 * Get localized language list
 * @param $all
 *   TRUE for all languages, not only enabled
 */
function i18n_language_list($all = FALSE) {
  static $languages;
  $type = $all ? 'name' : 'active';
  if(isset($languages[$type])) {
    return $languages[$type];
  } else {
    return $languages[$type] = array_map('t', i18n_languages($type));
  }
}

/**
 * Get list of supported languages
 * @param $all
 *   TRUE to get all defined languages
 */
function i18n_supported_languages($all = FALSE) {
  return i18n_languages($all ? 'name' :'active');
}

/**
 * Returns default language
 */
function i18n_default_language(){
  return i18n_languages('site_default'); 
}

/**
 * Check whether language is RTL
 * 
 * @param $language
 *   Language to check, defaults to current language
 */
function i18n_language_rtl($language = NULL) {
  $language = $language ? $language : i18n_get_lang();
  return i18n_language_property($language, 'rtl') ? TRUE : FALSE;
}

/**
 * Get language properties
 * 
 * @param $code
 *   Language code
 * @param $property
 *   It may be 'name', 'native', 'ltr'...
 */
function i18n_language_property($code, $property = 'native') {
  $languages = i18n_languages($property);
  return $languages[$code];
}

/**
 * Get locale languages plus i18n language settings
 * 
 * @param $key
 *   Data to be returned, defaults to 'active'
 *   'active' => array of enabled languages with native name
 *   'enabled' => array of enabled languages with english name
 *   'name' => all languages defined in locale module with english name
 *   'site_default' => code of default site language
 */
function i18n_languages($key = 'active') {
  static $languages;
  if (!$languages) {
    if($languages = variable_get('i18n_languages', 0)) {
      foreach($languages['name'] as $code => $name) {
        if($languages['enabled'][$code]) {
          $languages['active'][$code] = $name;
        }
      }
    } else {
      // It is possible that languages are not initialized
      if (function_exists('locale_supported_languages')) {
        $languages = locale_supported_languages();
      } else {
        // Worst case scenario: locale module not loaded, for cached pages, at least this won't break everything
        unset($languages); // There's some PHP bug: http://www.zend.com/zend/week/week98.php
        $languages['name'] = array('en' => 'English');
      }
      $languages['site_default'] = key($languages['name']);
      $languages['active'] = $languages['name'];
      $languages['native'] = $languages['name'];
    }
  }
  return $key ? $languages[$key] : $languages;
}

/**
 * Get language from browser settings, but only if it is a valid language
 */
function i18n_get_browser_lang() {
  $languages = i18n_supported_languages();
  $exploded_server = explode(";", $_SERVER["HTTP_ACCEPT_LANGUAGE"]);
  $accept=explode(',', array_shift($exploded_server));
  foreach ($accept as $lang) {
    if(empty($lang)) {
      continue;
    } elseif (array_key_exists($lang, $languages)) {
      return $lang;
    } elseif (array_key_exists(substr($lang, 0, 2), $languages)) {
      return substr($lang, 0, 2);
    }
  }
}

/**
 * Get language code from path.
 *
 * @param $path
 * @param $trim
 *   TRUE to remove language code from $path
 */
function i18n_get_lang_prefix(&$path, $trim = FALSE) {
  $exploded_path = explode('/', $path);
  $maybelang = array_shift($exploded_path);
  $languages = i18n_supported_languages();
  if(array_key_exists($maybelang, $languages)){
    if($trim) {
      $path = trim(substr($path, strlen($maybelang)),'/');
    }
    return $maybelang;
  }
}

/**
 * Language dependent front page
 * This function will search for aliases like 'en/home', 'es/home'...
 */
function i18n_frontpage($lang = NULL) {
  $lang = $lang ? $lang : _i18n_get_lang();
  return i18n_get_normal_path($lang.'/'.variable_get('site_frontpage','node'));
}

/**
 * This function is similar to drupal_get_normal_path, but language-aware
 * Also removes language from path
 */
function i18n_get_normal_path($path) {
  $prefix = i18n_get_lang_prefix($path, TRUE);
  if(!$prefix || _i18n_is_bootstrap()){
    // If bootstrap, drupal_lookup_path is not defined
    return $path; 
  } // First, check alias with lang
  elseif($alias = drupal_lookup_path('source', $prefix.'/'.$path)){
    i18n_get_lang_prefix($alias, TRUE); // In case alias has language
    return $alias;
  } // Check alias without lang
  elseif($alias = drupal_lookup_path('source', $path)){
    i18n_get_lang_prefix($alias, TRUE);
    return $alias;
  } 
  else {
    return $path;
  }
}

/**
 * More i18n API
 */

/**
 * Produces i18n paths, with language prefix
 * If path is empty or site frontpage, path = 'lang'
 * Check for frontpage and search for alias before adding language
 */
function i18n_path($path, $lang) {
  if (!$path || $path == i18n_frontpage($lang)) {
    return $lang;
  } elseif($alias = drupal_lookup_path('alias', $path)) {
	  if($prefix = i18n_get_lang_prefix($alias)) {
      // This alias will be valid only if it has the same language
	    return ($prefix == $lang) ? $alias : $lang.'/'.$path;
	  } else { // Alias without language prefix
	    return $lang.'/'.$alias;
	  }
  } else { // Alias for language path will be searched later
    return $lang.'/'.$path;  
  } 
}

/**
 * Get node language
 */
function i18n_node_get_lang($nid, $default = '') {
  $lang = db_result(db_query('SELECT language FROM {i18n_node} WHERE nid=%d',$nid));
  return $lang ? $lang : $default ;
}

/**
 * Get allowed languages for node
 * 
 * This allows node types to define its own language list implementing hook 'language_list'
 */
function i18n_node_language_list($node) {
  if ($languages = node_invoke($node, 'language_list')) {
    return $languages; // The node module manages its own language list
  } elseif(variable_get('i18n_node_'.$node->type, 0) == LANGUAGE_SUPPORT_EXTENDED) {
    return i18n_language_list(TRUE); // All defined languages
  } else {
    return i18n_language_list(); // All enabled languages
  }
}

/**
 * Returns main language, two letter code
 */
function i18n_get_main_lang($lang = NULL){
  $lang = $lang ? $lang : i18n_get_lang();
  return substr($lang, 2);
}

/**
 * Function i18n_get_links
 * 
 * Returns an array of links for all languages, with or without names/flags
 * 
 * @param $path
 *   Drupal internal path
 * @param $query
 *   Query string
 * @param $names
 *   Names to use for the links. Defaults to native language names
 */
function i18n_get_links($path = '', $query = NULL, $names = NULL) {
  if($path == i18n_frontpage()) {
    $path = '';
  }
  $names = $names ? $names : i18n_languages('native');
  foreach (array_keys(i18n_supported_languages()) as $lang){
    $links[$lang]= theme('i18n_link', $names[$lang], i18n_path($path, $lang), $lang, $query);
  }
  return $links;  
}

/**
 * Returns list of enabled languages from locale module
 *
 * Some code borrowed from locale module.
 * And yes, if locale enabled, languages are cached twice. But better twice than never ;-)
 */
function _i18n_locale_supported_languages() {
  if(function_exists('locale_supported_languages')){
    $languages = locale_supported_languages();
    return $languages['name'];
  } else {
    $result = db_query('SELECT locale, name FROM {locales_meta} WHERE enabled = 1 ORDER BY isdefault DESC, name ASC');
    while ($row = db_fetch_object($result)) {
      $enabled[$row->locale] = $row->name;
    }
    return $enabled;
  }
}

/**
 * Emulates drupal_goto, it may not be loaded yet
 */
function _i18n_goto($lang){
  if(!function_exists('drupal_goto')){
    require_once './includes/common.inc';
    require_once './includes/path.inc';   
  }
  drupal_goto($lang);
}

/**
 * i18n_selection_mode
 * 
 * Allows several modes for query rewriting and to change them programatically
 * 	off = No language conditions inserted
 * 	simple = Only current language and no language
 * 	mixed = Only current and default languages
 *  strict = Only current language
 *  default = Only default language
 *  user = User defined, in the module's settings page
 *  params = Gets the stored params
 *  reset = Returns to previous
 *  custom = add custom where clause, like "%alias.language = 'en'"
 */
function i18n_selection_mode($mode= NULL, $params= NULL){
  static $current_mode = 'simple';
  static $current_value = '';
  static $store = array();
  
  if(!$mode) {
    return $current_mode;
  } elseif($mode == 'params'){
    return $current_value;
  } elseif($mode == 'reset'){
    list($current_mode, $current_value) = array_pop($store);
    //drupal_set_message("i18n mode reset mode=$current_mode value=$current_value");
  } else {
    array_push($store, array($current_mode, $current_value));
    $current_mode = $mode;
    $current_value = $params;
  } 
}
// List of selection modes
function _i18n_selection_mode(){
  return array(
    'simple' => t('Only current language and no language'),
    'mixed' => t('Only current and default languages and no language'),
    'default' => t('Only default language and no language'),    
    'strict' => t('Only current language'),
    'off' => t('All content. No language conditions apply'),    
  );
}
// List of language support modes for content
function _i18n_content_languages() {
  return array(
    LANGUAGE_SUPPORT_NONE => t('Disabled'),
    LANGUAGE_SUPPORT_NORMAL => t('Normal - All enabled languages will be allowed.'),
    LANGUAGE_SUPPORT_EXTENDED => t('Extended - All defined languages will be allowed.')
  );
}

/**
 * @name Themeable functions
 * @{
 */
  
/**
 * Produces a language link with the right flag
 */
function theme_i18n_link($text, $target, $lang, $query= NULL, $fragment = NULL){
  $output = '<span class="i18n-link">';
  $attributes = ($lang == i18n_get_lang()) ? array('class' => 'active') : NULL;
  $output .= l(theme('i18n_language_icon', $lang), $target, $attributes, $query, $fragment, FALSE, TRUE);
  $output .= "&nbsp;";
  $output .= l($text, $target, $attributes, $query, $fragment, FALSE, TRUE);
  $output .= '</span>';
  return $output;
}

/**
 * Theme language icon
 * 
 * This function can be overridden for no language icons
 */
function theme_i18n_language_icon($lang){
  if ($path = variable_get('i18n_icon_path', drupal_get_path('module', 'i18n').'/flags/*.png')) {
    $languages = i18n_supported_languages();
    $src = base_path().str_replace('*', $lang, $path);
    list($width, $height) = explode('x', variable_get('i18n_icon_size', '16x12'));
    $attribs = array('class' => 'i18n-icon', 'width' => $width, 'height' => $height, 'alt' => $languages[$lang]);
    return "<img src=\"$src\" ".drupal_attributes($attribs)." />";
  }  
}

/* @} */

/**
 * Implementation of conf_url_rewrite
 * 
 * This is a conditional definition, just in case it is defined somewhere else.
 * If so, path rewriting won't work properly but at least it won't break Drupal
 */

if(!function_exists('custom_url_rewrite')) {
  function custom_url_rewrite($type, $path, $original) {
    return i18n_url_rewrite($type, $path, $original);
  }
}  

/**
 * Rewrites path with current language
 */
function i18n_url_rewrite($type, $path, $original){
  if ($type == 'alias' && !i18n_get_lang_prefix($path) ){
    return $path ? i18n_get_lang() . '/'. $path : i18n_get_lang();
  } else {
    return $path;
  } 
} 

/**
 * Implementation of hook_db_rewrite_sql()
 */
function i18n_db_rewrite_sql($query, $primary_table, $primary_key){
  // Some exceptions for query rewrites
  $mode = i18n_selection_mode();
  // drupal_set_message("i18n_db_rewrite mode=$mode query=$query");
  if ($mode == 'off') return;
  // Special case. Selection mode is 'strict' but this should be only for node queries
  if ($mode == 'strict' && $primary_table != 'n' && $primary_table != 'node') {
    $mode = 'simple';
  }
  switch ($primary_table) {
    case 'n':
    case 'node':
      // Node queries. 
      // When loading specific nodes, language conditions shouldn't apply
      if (preg_match("/WHERE.*\s$primary_table.nid\s*=\s*(\d|%d)/", $query)) return;
      // If language conditions already there, get out
      if (preg_match("/i18n/", $query)) return;
      
      $result['join'] = "LEFT JOIN {i18n_node} i18n ON $primary_table.nid = i18n.nid";
      $result['where'] = i18n_db_rewrite_where('i18n', $mode);
      return $result;
    case 't':
    case 'v':
      // Taxonomy queries
      // When loading specific terms, vocabs, language conditions shouldn't apply
      if (preg_match("/WHERE.* $primary_table\.tid\s*(=\s*\d|IN)/", $query)) return;
      // Taxonomy for specific node
      if (preg_match("/WHERE r\.nid = \%d/", $query)) return;
      $result['where'] = i18n_db_rewrite_where($primary_table, $mode);
      return $result;
    case 'm':
      // Menu queries. Rewrite mode is always 'simple' to avoid trouble with cache
      $result['where'] = i18n_db_rewrite_where($primary_table, 'simple');
      return $result;
  }
}

/**
 * Rewrites queries depending on rewriting mode
 */
function i18n_db_rewrite_where($alias, $mode){
  switch($mode){
    case 'simple':
      return "$alias.language ='".i18n_get_lang()."' OR $alias.language ='' OR $alias.language IS NULL" ;
    case 'mixed':
      return "$alias.language ='".i18n_get_lang()."' OR $alias.language ='".i18n_default_language()."' OR $alias.language ='' OR $alias.language IS NULL" ;
    case 'strict':
      return "$alias.language ='".i18n_get_lang()."'" ;
    case 'node':
    case 'translation':
      return "$alias.language ='".i18n_selection_mode('params')."' OR $alias.language ='' OR $alias.language IS NULL" ;
    case 'default':
      return "$alias.language ='".i18n_default_language()."' OR $alias.language ='' OR $alias.language IS NULL" ;
    case 'custom':
      return str_replace('%alias', $alias, i18n_selection_mode('params'));
  }  
}

/**
 * Implementation of hook_exit
 */
function i18n_exit(){
  _i18n_variable_exit();
}

/**
 * Implementation of hook_form_alter
 * 
 * This is the place to add language fields to all forms
 */
function i18n_form_alter($form_id, &$form) {
  //drupal_set_message("DEBUG: i18n_form_alter form_id=$form_id ");
  switch($form_id){
    case 'taxonomy_overview_vocabularies':
      $vocabularies = taxonomy_get_vocabularies();
      $languages = i18n_supported_languages();
      foreach ($vocabularies as $vocabulary) {
        if($vocabulary->language) $form[$vocabulary->vid]['type']['#value'] = $form[$vocabulary->vid]['type']['#value'].'&nbsp('.$languages[$vocabulary->language].')';
      }
        break;
    case 'taxonomy_form_vocabulary': // Taxonomy vocabulary
      if(isset($form['vid'])) {
        $vocabulary = taxonomy_get_vocabulary($form['vid']['#value']);
      } 
      $form['i18n'] = array('#type' => 'fieldset', '#title' => t('Multilingual options'), '#collapsible' => TRUE, '#weight' => -20);
      $form['i18n']['language'] = _i18n_language_select(isset($vocabulary) ? $vocabulary->language : i18n_get_lang(),t('This language will be set for all terms in this vocabulary')); 
      break;
      
    case 'taxonomy_form_term': // Taxonomy term
      if(isset($form['tid']) && is_numeric($form['tid']['#value'])) {
        $term = taxonomy_get_term($form['tid']['#value']);
      } 
      $form['language'] = _i18n_language_select(isset($term) ? $term->language : i18n_get_lang());
      break;
     
     case 'node_type_form':
       $node_type = $form['old_type']['#value'];
       $form['workflow']['i18n_node'] = array(
         '#type' => 'radios',
         '#title' => t('Multilingual support'),
         '#default_value' => variable_get('i18n_node_'.$node_type, 0),
         '#options' => _i18n_content_languages(),
         '#description' => t('Enables language field and multilingual support for this content type.'),
       );
       break;
     case '_locale_admin_manage_screen': // Locale language settings
       $languages = locale_supported_languages(TRUE, TRUE);
       $i18nlangs = variable_get('i18n_languages', array());
       $form['native'] = array('#tree' => TRUE);
       foreach ($languages['name'] as $key => $lang) {
          $options[$key] = '';

          $form['native'][$key] = array('#type' => 'textfield',
            '#default_value' => $i18nlangs['native'][$key] ? $i18nlangs['native'][$key] : $lang,
            '#size' => 15,
            '#maxlength' => 64,
          );
        }   
        $form['rtl'] = array(
          '#type' => 'checkboxes',
          '#options' => $options,
          '#default_value' => $i18nlangs['rtl']
        );
        $form['#base'] = 'i18n_admin_manage_screen';
        if(!is_array($form['#submit'])) {
          $form['#submit'] = array('_locale_admin_manage_screen_submit' => array());
        }
        $form['#submit'] = array('i18n_admin_manage_screen_submit' => array()) + $form['#submit'];
      break;
    case 'menu_edit_item_form':
      if ($mid = $form['mid']['#value']) {
        $language = db_result(db_query('SELECT language FROM {menu} WHERE mid = %d', $mid));
      } else {
        $language = '';
      }
      $form['language'] = _i18n_language_select($language, t('You can set a language for this menu item.')); 
      $form['#submit'] = array('i18n_menu_edit_item_form_submit' => array());
      break;   
    default:
      // Node edit form
      if (isset($form['type']) && $form['type']['#value'] .'_node_form' == $form_id && $node = $form['#node']) {
        // Language field
        if(variable_get('i18n_node_'.$form['type']['#value'], 0) && !isset($form['i18n']['language'])) {
          // Language field
          $form['i18n'] = array('#type' => 'fieldset', '#title' => t('Multilingual settings'), '#collapsible' => TRUE, '#collapsed' => FALSE, '#weight' => -4);
          // Language will default to current only when creating a node
          $language = isset($form['#node']->language) ? $form['#node']->language : (arg(1)=='add' ? i18n_get_lang() : '');
          $form['i18n']['language'] = _i18n_language_select($language, t('If you change the Language, you must click on <i>Preview</i> to get the right Categories &amp; Terms for that language.'), -4, i18n_node_language_list($node));
        }
        // Correction for lang/node/nid aliases generated by path module
        // if($form['#node']->path && $form['#node']->path == i18n_get_lang().'/node/'.$form['#node']->nid){
        if($node->path) {
          $alias = drupal_lookup_path('alias', 'node/'.$node->nid);
          if($alias && $alias != 'node/'.$node->nid){
            $form['#node']->path = $alias;
          } else {
            unset($form['#node']->path);
          }
        }
      }
      // Multilingual variables in settings form
      if ($form['#base'] == 'system_settings_form' && $variables = variable_get('i18n_variables', 0)) {
        if(i18n_form_alter_settings($form, $variables)) {
          $form['#submit'] = array('i18n_variable_form_submit' => array());
        }
      }
  }    
}

/**
 * Implementation of hook_perm().
 * 
 * Permissions defined
 * - administer all languages
 *   Disables language conditions for administration pages, so the user can view objects for all languages at the same time.
 *   This applies for: menu items, taxonomy
 */
function i18n_perm() {
  return array('administer all languages');
}
/**
 * Process menu and menu item add/edit form submissions.
 */
function i18n_menu_edit_item_form_submit($form_id, $form_values) {
  $mid = menu_edit_item_save($form_values);
  db_query("UPDATE {menu} SET language = '%s' WHERE mid = %d", $form_values['language'], $mid);
  return 'admin/build/menu';
}

/**
 * Theme the locale admin manager form.
 */
function theme_i18n_admin_manage_screen($form) {
  foreach ($form['name'] as $key => $element) {
    // Do not take form control structures.
    if (is_array($element) && element_child($key)) {
      $rows[] = array(check_plain($key), drupal_render($form['name'][$key]), drupal_render($form['native'][$key]), drupal_render($form['enabled'][$key]), drupal_render($form['site_default'][$key]), drupal_render($form['rtl'][$key]),($key != 'en' ? drupal_render($form['translation'][$key]) : t('n/a')), ($key != 'en' ? l(t('delete'), 'admin/settings/locale/language/delete/'. $key) : ''));
    }
  }
  $header = array(array('data' => t('Code')), array('data' => t('English name')), array('data' => t('Native name')), array('data' => t('Enabled')), array('data' => t('Default')), array('data' => t('RTL')), array('data' => t('Translated')), array('data' => t('Operations')));
  $output = theme('table', $header, $rows);
  $output .= drupal_render($form);

  return $output;
}

/**
 * Save language settings in variable
 */
function i18n_admin_manage_screen_submit($form_id, $form_values) {
  // Save changes to existing languages.
  foreach(array('site_default', 'name', 'rtl', 'native', 'enabled') as $key) {
    $save[$key] = $form_values[$key];
  }
  $save['name']['en'] = 'English';
  $languages = locale_supported_languages(FALSE, TRUE);
  foreach($languages['name'] as $key => $lang) {
   // Nothing 
  }
  variable_set('i18n_languages', $save);
}
/**
 * Check for multilingual variables in form
 */
function i18n_form_alter_settings(&$form, &$variables) {
  $result = 0;
  foreach(element_children($form) as $field) {
    if($form[$field]['#type'] == 'fieldset') {
      $result += i18n_form_alter_settings($form[$field], $variables);
    }
    elseif (in_array($field, $variables)) {
      $form[$field]['#description'] .= ' <strong>'.t('This is a multilingual variable.').'</strong>';
      $result++;
    }
  }
  return $result;
}

/**
 * Save multilingual variables and remove them from form
 */
function i18n_variable_form_submit($form_id, $form_values) {
  $op = isset($form_values['op']) ? $form_values['op'] : '';
  $variables = variable_get('i18n_variables', array());
  $language = i18n_get_lang();
  foreach ($form_values as $key => $value) {
    if(in_array($key, $variables)) {
      if ($op == t('Reset to defaults')) {
        i18n_variable_del($key, $language);
      }
      else {
        if (is_array($value) && isset($form_values['array_filter'])) {
          $value = array_keys(array_filter($value));
        }
        i18n_variable_set($key, $value, $language);
      }
      unset($form_values[$key]);
    } 
  }
  // Re-submit form
  system_settings_form_submit($form_id, $form_values);
}

/**
 * Initialization of multilingual variables 
 */
function i18n_variable_init(){
  global $conf;
  global $i18n_conf;
  $lang = _i18n_get_lang();
  if($i18n_variables = variable_get('i18n_variables', '')){
    $i18n_conf = array();
    $variables = _i18n_variable_init();
    foreach($i18n_variables as $name){
      $i18n_conf[$name] = isset($variables[$name]) ? $variables[$name] : (isset($conf[$name]) ? $conf[$name] : '');
    }
    $conf = array_merge($conf, $i18n_conf);
  }
}

/**
 * Set a persistent language dependent variable.
 *
 * @param $name
 *   The name of the variable to set.
 * @param $value
 *   The value to set. This can be any PHP data type; these functions take care
 *   of serialization as necessary.
 */
function i18n_variable_set($name, $value, $language) {
  global $conf, $i18n_conf;

  db_lock_table('i18n_variable');
  db_query("DELETE FROM {i18n_variable} WHERE name = '%s' AND language='%s'", $name, $language);
  db_query("INSERT INTO {i18n_variable} (name, language, value) VALUES ('%s', '%s', '%s')", $name, $language, serialize($value));
  db_unlock_tables();

  cache_clear_all('variables:'.$language, 'cache');

  $conf[$name] = $value;
  $i18n_conf[$name] = $value;
}

/**
 * Unset a persistent multilingual variable.