i18n.module

<?php
// $Id: i18n.module,v 1.41.2.49.2.1 2010/09/14 11:30:30 jareyero Exp $

/**
 * @file
 * Internationalization (i18n) module.
 *
 * This module extends multilingual support being the base module for the i18n package.
 * - Multilingual variables
 * - Extended languages for nodes
 * - Extended language API
 *
 * @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);
define('LANGUAGE_SUPPORT_EXTENDED_NOT_DISPLAYED', 3);

/**
 * Implements hook_init().
 *
 * Special fix for site_frontpage, that may have been used before the language variables are loaded.
 */
function i18n_init() {
  // If not in bootstrap, variable init. Otherwise we are serving a cached page so we don't need anything else.
  if (!_i18n_is_bootstrap()) {
    _i18n_init_mode();
  }
}

/**
 * Initialize selection mode
 */
function _i18n_init_mode() {
  if (i18n_selection_mode() != 'off') {
    // Node language when loading specific nodes or creating translations.
    if (arg(0) == 'node' ) {
      if (($node = menu_get_object('node')) && $node->language) {
        i18n_selection_mode('node', $node->language);
      }
      elseif (arg(1) == 'add' && !empty($_GET['translation']) && !empty($_GET['language'])) {
        i18n_selection_mode('translation', db_escape_string($_GET['language']));
      }
    }
    elseif (arg(0) == 'admin') {
      // There are some exceptions for admin pages.
      if (arg(1) == 'content' && user_access('administer all languages')) {
        // No restrictions for administration pages.
        i18n_selection_mode('off');
      }
      elseif (arg(1) == 'build' && (arg(2) == 'menu-customize' || arg(2) == 'menu')) {
        // All nodes available when editing custom menu items.
        i18n_selection_mode('off');
      }
    }
  }
}

/**
 * Implements hook_help().
 */
function i18n_help($path = 'admin/help#i18n', $arg) {
  switch ($path) {
    case 'admin/help#i18n' :
      $output = '<p>'. t('This module improves support for multilingual content in Drupal sites:') .'</p>';
      $output .= '<ul>';
      $output .= '<li>'. t('Shows content depending on page language.') .'</li>';
      $output .= '<li>'. t('Handles multilingual variables.') .'</li>';
      $output .= '<li>'. t('Extended language option for chosen content types. For these content types transations will be allowed for all defined languages, not only for enabled ones.') .'</li>';
      $output .= '<li>'. t('Provides a block for language selection and two theme functions: <em>i18n_flags</em> and <em>i18n_links</em>.') .'</li>';
      $output .= '</ul>';
      $output .= '<p>'. t('This is the base module for several others adding different features:') .'</p>';
      $output .= '<ul>';
      $output .= '<li>'. t('Multilingual menu items.') .'</li>';
      $output .= '<li>'. t('Multilingual taxonomy adds a language field for taxonomy vocabularies and terms.') .'</li>';
      $output .= '</ul>';
      $output .= '<p>'. t('For more information, see the online handbook entry for <a href="@i18n">Internationalization module</a>.', array('@i18n' => 'http://drupal.org/node/133977')) .'</p>';
      return $output;

    case 'admin/config/language/i18n':
      $output = '<ul>';
      $output .= '<li>'. t('To enable multilingual support for specific content types go to <a href="@configure_content_types">configure content types</a>.', array('@configure_content_types' => url('admin/structure/types'))) .'</li>';
      $output .= '</ul>';
      return $output;
  }
}

/**
 * Implements hook_menu().
 */
function i18n_menu() {
  $items['admin/config/regional/i18n'] = array(
    'title' => 'Multilingual system',
    'description' => 'Configure extended options for multilingual content and translations.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('i18n_admin_settings'),
    'access arguments' => array('administer site configuration'),
    'file' => 'i18n.admin.inc',
    'weight' => 10,
  );
  $items['admin/config/regional/i18n/configure'] = array(
    'title' => 'Multilingual system',
    'description' => 'Configure extended options for multilingual content and translations.',
    //'page callback' => 'drupal_get_form',
    //'page arguments' => array('i18n_admin_settings'),
    //'access arguments' => array('administer site configuration'),
    'file' => 'i18n.admin.inc',
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );
  return $items;
}

/**
 * Implements hook_user_login().
 *
 * Switch to user's language after login.
 */
function i18n_user_login(&$edit, &$account) {
  if ($account->language) {
    $_SESSION['language'] = $account->language;
    i18n_get_lang($account->language);
  }
}

/**
 * Simple i18n API
 */

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

/**
 * Selection mode for content.
 *
 * Warning: when used with params they need to be escaped, as some values are thrown directly in queries.
 *
 * 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'".
 *
 * @param $reset
 * 	 Whether to reset the internal cache for the selection mode.
 */
function i18n_selection_mode($mode = NULL, $params = NULL, $reset = FALSE) {
  $current_mode = &drupal_static(__FUNCTION__ . '_mode', NULL, $reset);
  $current_mode = &drupal_static(__FUNCTION__ . '_value', '', $reset);
  $store = &drupal_static(__FUNCTION__ . '_store', '', $reset);

  // Initialization, first time this runs
  if (!isset($current_mode)) {
    $current_mode = variable_get('i18n_selection_mode', 'simple');
  }

  if (!$mode) {
    return $current_mode;
  }
  elseif ($mode == 'params') {
    return $current_value;
  }
  elseif ($mode == 'reset') {
    list($current_mode, $current_value) = array_pop($store);
  }
  else {
    array_push($store, array($current_mode, $current_value));
    $current_mode = $mode;
    $current_value = $params;
  }
}

/**
 * Implements hook_db_rewrite_sql().
 *
 * Rewrite node queries so language selection options are enforced.
 */
function i18n_db_rewrite_sql($query, $primary_table, $primary_key, $args = array()) {
  // If mode is 'off' = no rewrite, we cannot return any empty 'where' string so check here.
  $mode = i18n_selection_mode();
  if ($mode == 'off') return;

  // Disable language conditions for views.
  if (array_key_exists('view', $args)) return;

  switch ($primary_table) {
    case 'n':
    case 'node':
      // No rewrite for queries with subselect ? (views count queries).
      // @ TO DO Actually these queries look un-rewrittable, check with other developers.
      if (preg_match("/FROM \(SELECT/", $query)) return;
      // No rewrite for translation module queries.
      if (preg_match("/.*FROM {node} $primary_table WHERE.*$primary_table\.tnid/", $query)) return;
      // When loading specific nodes, language conditions shouldn't apply.
      if (preg_match("/WHERE.*\s$primary_table.nid\s*=\s*(\d|%d)/", $query)) return;
      // If language conditions already there, get out.
      if (preg_match("/i18n/", $query)) return;


      // Mixed mode is a bit more complex, we need to join in one more table
      // and add some more conditions, but only if language is not default.
      if ($mode == 'mixed') {
        $result['where'] = i18n_db_rewrite_where($primary_table, 'node', 'simple');
        if (i18n_get_lang() != i18n_default_language()) {
          $result['join'] = "LEFT JOIN {node} i18n ON $primary_table.tnid > 0 AND $primary_table.tnid = i18n.tnid AND i18n.language = '". i18n_get_lang() ."'";
          // So we show also nodes that have default language.
          $result['where'] .= " OR $primary_table.language = '". i18n_default_language() ."' AND i18n.nid IS NULL";
        }
      }
      else {
        $result['where'] = i18n_db_rewrite_where($primary_table, 'node', $mode);
      }
      return $result;
  }
}

/**
 * Rewrites queries depending on rewriting mode.
 *
 * @return DatabaseCondition
 */
function i18n_db_rewrite_where($alias, $type, $mode = NULL) {
  if (!$mode) {
    // Some exceptions for query rewrites.
    $mode = i18n_selection_mode();
  }

  // Get languages to simplify query building.
  $current = i18n_get_lang();
  $default = i18n_default_language();

  if ($mode == 'strict' && $type != 'node') {
    // Special case. Selection mode is 'strict' but this should be only for node queries.
    $mode = 'simple';
  }
  elseif ($mode == 'mixed' && $current == $default) {
    // If mode is mixed but current = default, is the same as 'simple'.
    $mode = 'simple';
  }

  switch ($mode) {
    case 'off':
      return '';

    case 'simple':
      return db_condition('OR')
        ->condition($alias . '.language', $current)
        ->condition($alias . '.language', '')
        ->condition($alias . '.language', NULL);

    case 'mixed':
      return db_condition('OR')
        ->condition($alias . '.language', $current)
        ->condition($alias . '.language', $default)
        ->condition($alias . '.language', '')
        ->condition($alias . '.language', NULL);

    case 'strict':
      return db_condition('AND')->condition($alias . '.language', $current);

    case 'node':
    case 'translation':
      return db_condition('OR')
        ->condition($alias . '.language', i18n_selection_mode('params'))
        ->condition($alias . '.language', '')
        ->condition($alias . '.language', NULL);

    case 'default':
      return db_condition('OR')
        ->condition($alias . '.language', $default)
        ->condition($alias . '.language', '')
        ->condition($alias . '.language', NULL);

    case 'custom':
      return str_replace('%alias', $alias, i18n_selection_mode('params'));
  }
}

/**
 * Implements hook_preprocess_page().
 *
 * Add the language code to the classes for the <body> tag. Unfortunately, some
 * themes will not respect the variable we're modifying to achieve this - in
 * particular, Garland and Minelli do not.
 */
function i18n_preprocess_page(&$variables) {
  if (isset($variables['body_classes'])) {
    global $language;
    $variables['body_classes'] .= ' i18n-' . $language->language;
  }
}


/**
 * Implements hook_permission().
 *
 * 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
 * - administer translations
 *   Will allow to add/remove existing nodes to/from translation sets.
 */
function i18n_permission() {
  return array(
    'administer all languages' => array(
        'title' => t('Administer all languages'),
        'description' => t('Administer all languages.'),
    ),
    'administer translations' => array(
      'title' => t('Administer translations'),
      'description' => t('Administer translations.'),
    ),
  );
}

/**
 * Process menu and menu item add/edit form submissions.
 */
function i18n_menu_edit_item_form_submit($form, &$form_state) {
  $mid = menu_edit_item_save($form_state['values']);
  db_query("UPDATE {menu} SET language = '%s' WHERE mid = %d", array($form_state['values']['language'], $mid));
  return 'admin/build/menu';
}

/**
 * Get language from context.
 */
function _i18n_get_context_lang() {
  // Node language when loading specific nodes or creating translations.
  if (arg(0) == 'node' ) {
    if (($node = menu_get_object('node')) && $node->language) {
      return $node->language;
    }
    elseif (arg(1) == 'add' && !empty($_GET['translation']) && !empty($_GET['language'])) {
      return $_GET['language'];
    }
  }
}

/**
 * Check whether we are in bootstrap mode.
 */
function _i18n_is_bootstrap() {
  return !function_exists('drupal_get_headers');
}

/**
 * Drupal 6, backwards compatibility layer.
 *
 * @ TO DO Fully upgrade all the modules and remove
 */

/**
 * This one expects to be called first from common.inc
 */
function i18n_get_lang() {
  global $language;
  return $language->language;
}

/**
 * @defgroup i18n_api Extended language API
 * @{
 * This is an extended language API to be used by modules in i18n package.
 */

/**
 * Returns default language code.
 */
function i18n_default_language() {
  return language_default('language');
}

/**
 * Get list of supported languages, native name.
 *
 * @param $all
 *   TRUE to get all defined languages.
 */
function i18n_supported_languages($all = FALSE) {
  return locale_language_list('native', $all);
}

/**
 * @} End of "defgroup i18n_api".
 */