locale.inc

<?php
// $Id$

/**
 * @file
 * Administration functions for locale.module.
 */

/**
 * Regular expression pattern used to localize JavaScript strings.
 */
define('LOCALE_JS_STRING', '(?:(?:\'(?:\\\\\'|[^\'])*\'|"(?:\\\\"|[^"])*")(?:\s*\+\s*)?)+');

/**
 * Translation import mode overwriting all existing translations
 * if new translated version available.
 */
define('LOCALE_IMPORT_OVERWRITE', 0);

/**
 * Translation import mode keeping existing translations and only
 * inserting new strings.
 */
define('LOCALE_IMPORT_KEEP', 1);

/**
 * URL language negotiation: use the path prefix as URL language
 * indicator.
 */
define('LOCALE_LANGUAGE_NEGOTIATION_URL_PREFIX', 0);

/**
 * URL language negotiation: use the domain as URL language
 * indicator.
 */
define('LOCALE_LANGUAGE_NEGOTIATION_URL_DOMAIN', 1);

/**
 * @defgroup locale-language-overview Language overview functionality
 * @{
 */

/**
 * User interface for the language overview screen.
 */
function locale_languages_overview_form() {
  drupal_static_reset('language');
  $languages = language_list('language');

  $options = array();
  $form['weight'] = array('#tree' => TRUE);
  foreach ($languages as $langcode => $language) {

    $options[$langcode] = '';
    if ($language->enabled) {
      $enabled[] = $langcode;
    }
    $form['weight'][$langcode] = array(
      '#type' => 'weight',
      '#default_value' => $language->weight,
      '#attributes' => array('class' => array('language-order-weight')),
    );
    $form['name'][$langcode] = array('#markup' => check_plain($language->name));
    $form['native'][$langcode] = array('#markup' => check_plain($language->native));
    $form['direction'][$langcode] = array('#markup' => ($language->direction == LANGUAGE_RTL ? t('Right to left') : t('Left to right')));
  }
  $form['enabled'] = array('#type' => 'checkboxes',
    '#options' => $options,
    '#default_value' => $enabled,
  );
  $form['site_default'] = array('#type' => 'radios',
    '#options' => $options,
    '#default_value' => language_default('language'),
  );
  $form['submit'] = array('#type' => 'submit', '#value' => t('Save configuration'));
  $form['#theme'] = 'locale_languages_overview_form';

  return $form;
}

/**
 * Theme the language overview form.
 *
 * @param $variables
 *   An associative array containing:
 *   - form: @todo: document
 *
 * @return
 *   A themed HTML string representing the form.
 *
 * @ingroup themeable
 */
function theme_locale_languages_overview_form($variables) {
  $form = $variables['form'];
  $default = language_default();
  foreach ($form['name'] as $key => $element) {
    // Do not take form control structures.
    if (is_array($element) && element_child($key)) {
      // Disable checkbox for the default language, because it cannot be disabled.
      if ($key == $default->language) {
        $form['enabled'][$key]['#attributes']['disabled'] = 'disabled';
      }
      $rows[] = array(
        'data' => array(
          '<strong>' . drupal_render($form['name'][$key]) . '</strong>',
          drupal_render($form['native'][$key]),
          check_plain($key),
          drupal_render($form['direction'][$key]),
          array('data' => drupal_render($form['enabled'][$key]), 'align' => 'center'),
          drupal_render($form['site_default'][$key]),
          drupal_render($form['weight'][$key]),
          l(t('edit'), 'admin/config/regional/language/edit/' . $key) . (($key != 'en' && $key != $default->language) ? ' ' . l(t('delete'), 'admin/config/regional/language/delete/' . $key) : '')
        ),
        'class' => array('draggable'),
      );
    }
  }
  $header = array(array('data' => t('English name')), array('data' => t('Native name')), array('data' => t('Code')), array('data' => t('Direction')), array('data' => t('Enabled')), array('data' => t('Default')), array('data' => t('Weight')), array('data' => t('Operations')));
  $output = theme('table', array('header' => $header, 'rows' => $rows, 'attributes' => array('id' => 'language-order')));
  $output .= drupal_render_children($form);

  drupal_add_tabledrag('language-order', 'order', 'sibling', 'language-order-weight');

  return $output;
}

/**
 * Process language overview form submissions, updating existing languages.
 */
function locale_languages_overview_form_submit($form, &$form_state) {
  $languages = language_list();
  $default = language_default();
  $enabled_count = 0;
  foreach ($languages as $langcode => $language) {
    if ($form_state['values']['site_default'] == $langcode || $default->language == $langcode) {
      // Automatically enable the default language and the language
      // which was default previously (because we will not get the
      // value from that disabled checkox).
      $form_state['values']['enabled'][$langcode] = 1;
    }
    if ($form_state['values']['enabled'][$langcode]) {
      $enabled_count++;
      $language->enabled = 1;
    }
    else {
      $language->enabled = 0;
    }
    $language->weight = $form_state['values']['weight'][$langcode];
    db_update('languages')
      ->fields(array(
        'enabled' => $language->enabled,
        'weight' => $language->weight,
      ))
      ->condition('language', $langcode)
      ->execute();
    $languages[$langcode] = $language;
  }
  drupal_set_message(t('Configuration saved.'));
  variable_set('language_default', $languages[$form_state['values']['site_default']]);
  variable_set('language_count', $enabled_count);

  // Changing the language settings impacts the interface.
  cache_clear_all('*', 'cache_page', TRUE);
  module_invoke_all('multilingual_settings_changed');

  $form_state['redirect'] = 'admin/config/regional/language';
  return;
}
/**
 * @} End of "locale-language-overview"
 */

/**
 * @defgroup locale-language-add-edit Language addition and editing functionality
 * @{
 */

/**
 * User interface for the language addition screen.
 */
function locale_languages_add_screen() {
  $build['predefined'] = drupal_get_form('locale_languages_predefined_form');
  $build['custom'] = drupal_get_form('locale_languages_custom_form');
  return $build;
}

/**
 * Predefined language setup form.
 */
function locale_languages_predefined_form($form) {
  $predefined = _locale_prepare_predefined_list();
  $form['language list'] = array('#type' => 'fieldset',
    '#title' => t('Predefined language'),
    '#collapsible' => TRUE,
  );
  $form['language list']['langcode'] = array('#type' => 'select',
    '#title' => t('Language name'),
    '#default_value' => key($predefined),
    '#options' => $predefined,
    '#description' => t('Select the desired language and click the <em>Add language</em> button. (Use the <em>Custom language</em> options if your desired language does not appear in this list.)'),
  );
  $form['language list']['submit'] = array('#type' => 'submit', '#value' => t('Add language'));
  return $form;
}

/**
 * Custom language addition form.
 */
function locale_languages_custom_form($form) {
  $form['custom language'] = array('#type' => 'fieldset',
    '#title' => t('Custom language'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );
  _locale_languages_common_controls($form['custom language']);
  $form['custom language']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Add custom language')
  );
  // Reuse the validation and submit functions of the predefined language setup form.
  $form['#submit'][] = 'locale_languages_predefined_form_submit';
  $form['#validate'][] = 'locale_languages_predefined_form_validate';
  return $form;
}

/**
 * Editing screen for a particular language.
 *
 * @param $langcode
 *   Language code of the language to edit.
 */
function locale_languages_edit_form($form, &$form_state, $langcode) {
  if ($language = db_query("SELECT * FROM {languages} WHERE language = :language", array(':language' => $langcode))->fetchObject()) {
    _locale_languages_common_controls($form, $language);
    $form['submit'] = array(
      '#type' => 'submit',
      '#value' => t('Save language')
    );
    $form['#submit'][] = 'locale_languages_edit_form_submit';
    $form['#validate'][] = 'locale_languages_edit_form_validate';
    return $form;
  }
  else {
    drupal_not_found();
  }
}

/**
 * Common elements of the language addition and editing form.
 *
 * @param $form
 *   A parent form item (or empty array) to add items below.
 * @param $language
 *   Language object to edit.
 */
function _locale_languages_common_controls(&$form, $language = NULL) {
  if (!is_object($language)) {
    $language = new stdClass();
  }
  if (isset($language->language)) {
    $form['langcode_view'] = array(
      '#type' => 'item',
      '#title' => t('Language code'),
      '#markup' => $language->language
    );
    $form['langcode'] = array(
      '#type' => 'value',
      '#value' => $language->language
    );
  }
  else {
    $form['langcode'] = array('#type' => 'textfield',
      '#title' => t('Language code'),
      '#size' => 12,
      '#maxlength' => 60,
      '#required' => TRUE,
      '#default_value' => @$language->language,
      '#disabled' => (isset($language->language)),
      '#description' => t('<a href="@rfc4646">RFC 4646</a> compliant language identifier. Language codes typically use a country code, and optionally, a script or regional variant name. <em>Examples: "en", "en-US" and "zh-Hant".</em>', array('@rfc4646' => 'http://www.ietf.org/rfc/rfc4646.txt')),
    );
  }
  $form['name'] = array('#type' => 'textfield',
    '#title' => t('Language name in English'),
    '#maxlength' => 64,
    '#default_value' => @$language->name,
    '#required' => TRUE,
    '#description' => t('Name of the language in English. Will be available for translation in all languages.'),
  );
  $form['native'] = array('#type' => 'textfield',
    '#title' => t('Native language name'),
    '#maxlength' => 64,
    '#default_value' => @$language->native,
    '#required' => TRUE,
    '#description' => t('Name of the language in the language being added.'),
  );
  $form['prefix'] = array('#type' => 'textfield',
    '#title' => t('Path prefix'),
    '#maxlength' => 64,
    '#default_value' => @$language->prefix,
    '#description' => t('Language code or other custom string for pattern matching within the path. With language negotiation set to <em>Path prefix only</em> or <em>Path prefix with language fallback</em>, this site is presented in this language when the Path prefix value matches an element in the path. For the default language, this value may be left blank. <strong>Modifying this value will break existing URLs and should be used with caution in a production environment.</strong> <em>Example: Specifying "deutsch" as the path prefix for German results in URLs in the form "www.example.com/deutsch/node".</em>')
  );
  $form['domain'] = array('#type' => 'textfield',
    '#title' => t('Language domain'),
    '#maxlength' => 128,
    '#default_value' => @$language->domain,
    '#description' => t('Language-specific URL, with protocol. With language negotiation set to <em>Domain name only</em>, the site is presented in this language when the URL accessing the site references this domain. For the default language, this value may be left blank. <strong>This value must include a protocol as part of the string.</strong> <em>Example: Specifying "http://example.de" or "http://de.example.com" as language domains for German results in URLs in the forms "http://example.de/node" and "http://de.example.com/node", respectively.</em>'),
  );
  $form['direction'] = array('#type' => 'radios',
    '#title' => t('Direction'),
    '#required' => TRUE,
    '#description' => t('Direction that text in this language is presented.'),
    '#default_value' => @$language->direction,
    '#options' => array(LANGUAGE_LTR => t('Left to right'), LANGUAGE_RTL => t('Right to left'))
  );
  return $form;
}

/**
 * Validate the language addition form.
 */
function locale_languages_predefined_form_validate($form, &$form_state) {
  $langcode = $form_state['values']['langcode'];

  if (($duplicate = db_query("SELECT COUNT(*) FROM {languages} WHERE language = :language", array(':language' => $langcode))->fetchField()) != 0) {
    form_set_error('langcode', t('The language %language (%code) already exists.', array('%language' => $form_state['values']['name'], '%code' => $langcode)));
  }

  if (!isset($form_state['values']['name'])) {
    // Predefined language selection.
    include_once DRUPAL_ROOT . '/includes/iso.inc';
    $predefined = _locale_get_predefined_list();
    if (!isset($predefined[$langcode])) {
      form_set_error('langcode', t('Invalid language code.'));
    }
  }
  else {
    // Reuse the editing form validation routine if we add a custom language.
    locale_languages_edit_form_validate($form, $form_state);
  }
}

/**
 * Process the language addition form submission.
 */
function locale_languages_predefined_form_submit($form, &$form_state) {
  $langcode = $form_state['values']['langcode'];
  if (isset($form_state['values']['name'])) {
    // Custom language form.
    locale_add_language($langcode, $form_state['values']['name'], $form_state['values']['native'], $form_state['values']['direction'], $form_state['values']['domain'], $form_state['values']['prefix']);
    drupal_set_message(t('The language %language has been created and can now be used. More information is available on the <a href="@locale-help">help screen</a>.', array('%language' => t($form_state['values']['name']), '@locale-help' => url('admin/help/locale'))));
  }
  else {
    // Predefined language selection.
    include_once DRUPAL_ROOT . '/includes/iso.inc';
    $predefined = _locale_get_predefined_list();
    locale_add_language($langcode);
    drupal_set_message(t('The language %language has been created and can now be used. More information is available on the <a href="@locale-help">help screen</a>.', array('%language' => t($predefined[$langcode][0]), '@locale-help' => url('admin/help/locale'))));
  }

  // See if we have language files to import for the newly added
  // language, collect and import them.
  if ($batch = locale_batch_by_language($langcode, '_locale_batch_language_finished')) {
    batch_set($batch);
  }

  module_invoke_all('multilingual_settings_changed');

  $form_state['redirect'] = 'admin/config/regional/language';
  return;
}

/**
 * Validate the language editing form. Reused for custom language addition too.
 */
function locale_languages_edit_form_validate($form, &$form_state) {
  if (!empty($form_state['values']['domain']) && !empty($form_state['values']['prefix'])) {
    form_set_error('prefix', t('Domain and path prefix values should not be set at the same time.'));
  }
  if (!empty($form_state['values']['domain']) && $duplicate = db_query("SELECT language FROM {languages} WHERE domain = :domain AND language <> :language", array(':domain' => $form_state['values']['domain'], ':language' => $form_state['values']['langcode']))->fetchField()) {
    form_set_error('domain', t('The domain (%domain) is already tied to a language (%language).', array('%domain' => $form_state['values']['domain'], '%language' => $duplicate->language)));
  }
  if (empty($form_state['values']['prefix']) && language_default('language') != $form_state['values']['langcode'] && empty($form_state['values']['domain'])) {
    form_set_error('prefix', t('Only the default language can have both the domain and prefix empty.'));
  }
  if (!empty($form_state['values']['prefix']) && $duplicate = db_query("SELECT language FROM {languages} WHERE prefix = :prefix AND language <> :language", array(':prefix' => $form_state['values']['prefix'], ':language' => $form_state['values']['langcode']))->fetchField()) {
    form_set_error('prefix', t('The prefix (%prefix) is already tied to a language (%language).', array('%prefix' => $form_state['values']['prefix'], '%language' => $duplicate->language)));
  }
}

/**
 * Process the language editing form submission.
 */
function locale_languages_edit_form_submit($form, &$form_state) {
  db_update('languages')
    ->fields(array(
      'name' => $form_state['values']['name'],
      'native' => $form_state['values']['native'],
      'domain' => $form_state['values']['domain'],
      'prefix' => $form_state['values']['prefix'],
      'direction' => $form_state['values']['direction'],
    ))
    ->condition('language',  $form_state['values']['langcode'])
    ->execute();
  $default = language_default();
  if ($default->language == $form_state['values']['langcode']) {
    $properties = array('name', 'native', 'direction', 'enabled', 'plurals', 'formula', 'domain', 'prefix', 'weight');
    foreach ($properties as $keyname) {
      if (isset($form_state['values'][$keyname])) {
        $default->$keyname = $form_state['values'][$keyname];
      }
    }
    variable_set('language_default', $default);
  }
  $form_state['redirect'] = 'admin/config/regional/language';
  return;
}
/**
 * @} End of "locale-language-add-edit"
 */

/**
 * @defgroup locale-language-delete Language deletion functionality
 * @{
 */

/**
 * User interface for the language deletion confirmation screen.
 */
function locale_languages_delete_form($form, &$form_state, $langcode) {

  // Do not allow deletion of English locale.
  if ($langcode == 'en') {
    drupal_set_message(t('The English language cannot be deleted.'));
    drupal_goto('admin/config/regional/language');
  }

  if (language_default('language') == $langcode) {
    drupal_set_message(t('The default language cannot be deleted.'));
    drupal_goto('admin/config/regional/language');
  }

  // For other languages, warn user that data loss is ahead.
  $languages = language_list();

  if (!isset($languages[$langcode])) {
    drupal_not_found();
  }
  else {
    $form['langcode'] = array('#type' => 'value', '#value' => $langcode);
    return confirm_form($form, t('Are you sure you want to delete the language %name?', array('%name' => t($languages[$langcode]->name))), 'admin/config/regional/language', t('Deleting a language will remove all interface translations associated with it, and posts in this language will be set to be language neutral. This action cannot be undone.'), t('Delete'), t('Cancel'));
  }
}

/**
 * Process language deletion submissions.
 */
function locale_languages_delete_form_submit($form, &$form_state) {
  $languages = language_list();
  if (isset($languages[$form_state['values']['langcode']])) {
    // Remove translations first.
    db_delete('locales_target')
      ->condition('language', $form_state['values']['langcode'])
      ->execute();
    cache_clear_all('locale:' . $form_state['values']['langcode'], 'cache');
    // With no translations, this removes existing JavaScript translations file.
    _locale_rebuild_js($form_state['values']['langcode']);
    // Remove the language.
    db_delete('languages')
      ->condition('language', $form_state['values']['langcode'])
      ->execute();
    db_update('node')
      ->fields(array('language' => ''))
      ->condition('language', $form_state['values']['langcode'])
      ->execute();
    module_invoke_all('multilingual_settings_changed');
    $variables = array('%locale' => $languages[$form_state['values']['langcode']]->name);    
    drupal_set_message(t('The language %locale has been removed.', $variables));
    watchdog('locale', 'The language %locale has been removed.', $variables);
  }

  // Changing the language settings impacts the interface:
  cache_clear_all('*', 'cache_page', TRUE);

  $form_state['redirect'] = 'admin/config/regional/language';
  return;
}
/**
 * @} End of "locale-language-add-edit"
 */

/**
 * @defgroup locale-languages-negotiation Language negotiation options
 * @{
 */

/**
 * Setting for language negotiation options
 */
function locale_languages_configure_form() {
  include_once DRUPAL_ROOT . '/includes/language.inc';

  $form = array(
    '#submit' => array('locale_languages_configure_form_submit'),
    '#theme' => 'locale_languages_configure_form',
    '#language_types' => language_types_configurable(),
    '#language_types_info' => language_types_info(),
    '#language_providers' => language_negotiation_info(),
  );

  foreach ($form['#language_types'] as $type) {
    _locale_languages_configure_form_language_table($form, $type);
  }

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save settings'),
  );

  return $form;
}

/**
 * Helper function to build a language provider table.
 */
function _locale_languages_configure_form_language_table(&$form, $type) {
  $info = $form['#language_types_info'][$type];

  $table_form = array(
    '#title' => t('@type language', array('@type' => $info['name'])),
    '#tree' => TRUE,
    '#description' => $info['description'],
    '#language_providers' => array(),
    '#show_operations' => FALSE,
    'weight' => array('#tree' => TRUE),
    'enabled' => array('#tree' => TRUE),
  );

  $language_providers = $form['#language_providers'];
  $enabled_providers = variable_get("locale_language_providers_enabled_$type", array());
  $providers_weight = variable_get("locale_language_providers_weight_$type", array());

  // Add missing data to the providers lists.
  foreach ($language_providers as $id => $provider) {
    if (!isset($providers_weight[$id])) {
      $providers_weight[$id] = language_provider_weight($provider);
    }
    if (!isset($enabled_providers[$id])) {
      $enabled_providers[$id] = FALSE;
    }
  }

  // Order providers list by weight.
  asort($providers_weight);

  foreach ($providers_weight as $id => $weight) {
    $enabled = $enabled_providers[$id];
    $provider = $language_providers[$id];

    // List the provider only if the current type is defined in its 'types' key.
    // If it is not defined default to all the configurabe language types.
    $types = array_flip(isset($provider['types']) ? $provider['types'] : $form['#language_types']);

    if (isset($types[$type])) {
      $table_form['#language_providers'][$id] = $provider;

      $table_form['weight'][$id] = array(
        '#type' => 'weight',
        '#default_value' => $weight,
        '#attributes' => array('class' => array("language-provider-weight-$type")),
      );

      $table_form['title'][$id] = array('#markup' => check_plain($provider['name']));

      $table_form['enabled'][$id] = array('#type' => 'checkbox', '#default_value' => $enabled);
      if ($id === LANGUAGE_NEGOTIATION_DEFAULT) {
        $table_form['enabled'][$id]['#default_value'] = TRUE;
        $table_form['enabled'][$id]['#attributes'] = array('disabled' => 'disabled');
      }

      $table_form['description'][$id] = array('#markup' => filter_xss_admin($provider['description']));

      $config_op = '';
      if (isset($provider['config'])) {
        $config_op = l(t('Configure'), $provider['config']);
        // If there is at least one operation enabled show the operation column.
        $table_form['#show_operations'] = TRUE;
      }
      $table_form['operation'][$id] = array('#markup' => $config_op);
    }
  }

  $form[$type] = $table_form;
}

/**
 * Theme the language configure form.
 *
 * @ingroup themeable
 */
function theme_locale_languages_configure_form($variables) {
  $form = $variables['form'];
  $output = '';

  foreach ($form['#language_types'] as $type) {
    $rows = array();
    $info = $form['#language_types_info'][$type];
    $title = '<label>' . $form[$type]['#title'] . '</label>';
    $description = '<div class="description">' . $form[$type]['#description'] . '</div>';

    foreach ($form[$type]['title'] as $id => $element) {
      // Do not take form control structures.
      if (is_array($element) && element_child($id)) {
        $row = array(
          'data' => array(
            '<strong>' . drupal_render($form[$type]['title'][$id]) . '</strong>',
            drupal_render($form[$type]['description'][$id]),
            drupal_render($form[$type]['enabled'][$id]),
            drupal_render($form[$type]['weight'][$id]),
          ),
          'class' => array('draggable'),
        );
        if ($form[$type]['#show_operations']) {
          $row['data'][] = drupal_render($form[$type]['operation'][$id]);
        }
        $rows[] = $row;
      }
    }

    $header = array(
      array('data' => t('Detection method')),
      array('data' => t('Description')),
      array('data' => t('Enabled')),
      array('data' => t('Weight')),
    );

    // If there is at least one operation enabled show the operation column.
    if ($form[$type]['#show_operations']) {
      $header[] = array('data' => t('Operations'));
    }

    $variables = array(
      'header' => $header,
      'rows' => $rows,
      'attributes' => array('id' => "language-negotiation-providers-$type"),
    );
    $table  = theme('table', $variables);
    $table .= drupal_render_children($form[$type]);

    drupal_add_tabledrag("language-negotiation-providers-$type", 'order', 'sibling', "language-provider-weight-$type");

    $output .= '<div class="form-item">' . $title . $description . $table . '</div>';
  }

  $output .= drupal_render_children($form);
  return $output;
}

/**
 * Submit handler for language negotiation settings.
 */
function locale_languages_configure_form_submit($form, &$form_state) {
  $language_types = array();
  $configurable_types = $form['#language_types'];

  foreach ($configurable_types as $type) {
    $negotiation = array();
    $enabled_providers = $form_state['values'][$type]['enabled'];
    $enabled_providers[LANGUAGE_NEGOTIATION_DEFAULT] = TRUE;
    $providers_weight = $form_state['values'][$type]['weight'];
    $language_types[$type] = TRUE;

    foreach ($providers_weight as $id => $weight) {
      if ($enabled_providers[$id]) {
        $provider = $form[$type]['#language_providers'][$id];
        $provider['weight'] = $weight;
        $negotiation[$id] = $provider;
      }
    }

    language_negotiation_set($type, $negotiation);
    variable_set("locale_language_providers_enabled_$type", $enabled_providers);
    variable_set("locale_language_providers_weight_$type", $providers_weight);
  }

  // Save non-configurable language types negotiation.
  $language_types_info = language_types_info();
  $defined_providers = $form['#language_providers'];
  foreach ($language_types_info as $type => $info) {
    if (isset($info['fixed'])) {
      $language_types[$type] = FALSE;
      $negotiation = array();
      foreach ($info['fixed'] as $id) {
        if (isset($defined_providers[$id])) {
          $negotiation[$id] = $defined_providers[$id];
        }
      }
      language_negotiation_set($type, $negotiation);
    }
  }

  // Save language types.
  variable_set('language_types', $language_types);

  $form_state['redirect'] = 'admin/config/regional/language';
  drupal_set_message(t('Language negotiation configuration saved.'));
}

/**
 * The URL language provider configuration form.
 */
function locale_language_providers_url_form() {
  $form = array();

  $form['locale_language_negotiation_url_part'] = array(
    '#title' => t('URL language indicator'),
    '#type' => 'radios',
    '#options' => array(
      LOCALE_LANGUAGE_NEGOTIATION_URL_PREFIX => t('Path prefix'),
      LOCALE_LANGUAGE_NEGOTIATION_URL_DOMAIN => t('Domain'),
    ),
    '#default_value' => variable_get('locale_language_negotiation_url_part', LOCALE_LANGUAGE_NEGOTIATION_URL_PREFIX),
    '#description' => t('Select which part of the URL will determine the language.'),
  );

  $form['#redirect'] = 'admin/config/regional/language/configure';

  return system_settings_form($form);
}

/**
 * The URL language provider configuration form.
 */
function locale_language_providers_session_form() {
  $form = array();

  $form['locale_language_negotiation_session_param'] = array(
    '#title' => t('Request/session parameter'),
    '#type' => 'textfield',
    '#default_value' => variable_get('locale_language_negotiation_session_param', 'language'),
    '#description' => t('This value will be the name of the request/session parameter which will be used to determine the desired language.'),
  );

  $form['#redirect'] = 'admin/config/regional/language/configure';

  return system_settings_form($form);
}

/**
 * Identify the language from the current content language.
 *
 * @return
 *   The current content language code.
 */
function locale_language_from_content() {
  global $language;
  return isset($language->language) ? $language->language : FALSE;
}

/**
 * Identify language from the Accept-language HTTP header we got.
 *
 * We perform browser accept-language parsing only if page cache is disabled,
 * otherwise we would cache a user-specific preference.
 *
 * @param $languages
 *   An array of valid language objects.
 *
 * @return
 *   A valid language code on success, FALSE otherwise.
 */
function locale_language_from_browser($languages) {
  // Specified by the user via the browser's Accept Language setting
  // Samples: "hu, en-us;q=0.66, en;q=0.33", "hu,en-us;q=0.5"
  $browser_langs = array();

  if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
    $browser_accept = explode(",", $_SERVER['HTTP_ACCEPT_LANGUAGE']);
    foreach ($browser_accept as $langpart) {
      // The language part is either a code or a code with a quality.
      // We cannot do anything with a * code, so it is skipped.
      // If the quality is missing, it is assumed to be 1 according to the RFC.
      if (preg_match("!([a-z-]+)(;q=([0-9\\.]+))?!", trim($langpart), $found)) {
        $browser_langs[$found[1]] = (isset($found[3]) ? (float) $found[3] : 1.0);
      }
    }
  }

  // Order the codes by quality
  arsort($browser_langs);

  // Try to find the first preferred language we have
  foreach ($browser_langs as $langcode => $q) {
    if (isset($languages[$langcode])) {
      return $langcode;
    }
  }

  return FALSE;
}

/**
 * Identify language from the user preferences.
 *
 * @param $languages
 *   An array of valid language objects.
 *
 * @return
 *   A valid language code on succes, FALSE otherwise.
 */
function locale_language_from_user($languages) {
  // User preference (only for logged users).
  global $user;

  if ($user->uid) {
    return $user->language;
  }

  // No language preference from the user.
  return FALSE;
}

/**
 * Identify language from a request/session parameter.
 *
 * @param $languages
 *   An array of valid language objects.
 *
 * @return
 *   A valid language code on succes, FALSE otherwise.
 */
function locale_language_from_session($languages) {
  $param = variable_get('locale_language_negotiation_session_param', 'language');

  // Request parameter.
  if (isset($_GET[$param]) && isset($languages[$langcode = $_GET[$param]])) {
    return $_SESSION[$param] = $langcode;
  }

  // Session parameter.
  if (isset($_SESSION[$param])) {
    return $_SESSION[$param];
  }

  return FALSE;
}

/**
 * Identify language via URL prefix or domain.
 *
 * @param $languages
 *   An array of valid language objects.
 *
 * @return
 *   A valid language code on succes, FALSE otherwise.
 */
function locale_language_from_url($languages) {
  $language_url = FALSE;

  switch (variable_get('locale_language_negotiation_url_part', LOCALE_LANGUAGE_NEGOTIATION_URL_PREFIX)) {
    case LOCALE_LANGUAGE_NEGOTIATION_URL_PREFIX:
      // $_GET['q'] might not be available at this time, because
      // path initialization runs after the language bootstrap phase.
      list($language, $_GET['q']) = language_url_split_prefix(isset($_GET['q']) ? $_GET['q'] : NULL, $languages);
      if ($language !== FALSE) {
        $language_url = $language->language;
      }
      break;

    case LOCALE_LANGUAGE_NEGOTIATION_URL_DOMAIN:
      foreach ($languages as $language) {
        $host = parse_url($language->domain, PHP_URL_HOST);
        if ($host && ($_SERVER['HTTP_HOST'] == $host)) {
          $language_url = $language->language;
          break;
        }
      }
      break;
  }

  return $language_url;
}

/**
 * Return the URL language switcher block. Translation links may be provided by
 * other modules.
 */
function locale_language_switcher_url($type, $path) {
  $languages = language_list('enabled');
  $links = array();

  foreach ($languages[1] as $language) {
    $links[$language->language] = array(
      'href'       => $path,
      'title'      => $language->native,
      'language'   => $language,
      'attributes' => array('class' => array('language-link')),
    );
  }

  return $links;
}

/**
 * Return the session language switcher block.
 */
function locale_language_switcher_session($type, $path) {
  drupal_add_css(drupal_get_path('module', 'locale') . '/locale.css');

  $param = variable_get('locale_language_negotiation_session_param', 'language');
  $language_query = isset($_SESSION[$param]) ? $_SESSION[$param] : $GLOBALS[$type]->language;

  $languages = language_list('enabled');
  $links = array();

  $query = $_GET;
  unset($query['q']);

  foreach ($languages[1] as $language) {
    $langcode = $language->language;
    $links[$langcode] = array(
      'href'       => $path,
      'title'      => $language->native,
      'attributes' => array('class' => array('language-link')),
      'query'      => $query,
    );
    if ($language_query != $langcode) {
      $links[$langcode]['query'][$param] = $langcode;
    }
    else {
      $links[$langcode]['attributes']['class'][] = ' session-active';
    }
  }

  return $links;
}

/**
 * Rewrite URLs for the URL language provider.
 */
function locale_language_url_rewrite_url(&$path, &$options) {
  // Language can be passed as an option, or we go for current URL language.
  if (!isset($options['language'])) {
    global $language_url;
    $options['language'] = $language_url;
  }

  if (isset($options['language'])) {
    switch (variable_get('locale_language_negotiation_url_part', LOCALE_LANGUAGE_NEGOTIATION_URL_PREFIX)) {
      case LOCALE_LANGUAGE_NEGOTIATION_URL_DOMAIN:
        if ($options['language']->domain) {
          // Ask for an absolute URL with our modified base_url.
          $options['absolute'] = TRUE;
          $options['base_url'] = $options['language']->domain;
        }
        break;

      case LOCALE_LANGUAGE_NEGOTIATION_URL_PREFIX:
        if (!empty($options['language']->prefix)) {
          $options['prefix'] = $options['language']->prefix . '/';
        }
        break;
    }
  }
}

/**
 * Rewrite URLs for the Session language provider.
 */
function locale_language_url_rewrite_session(&$path, &$options) {
  static $query_rewrite, $query_param, $query_value;

  // The following values are not supposed to change during a single page
  // request processing.
  if (!isset($query_rewrite)) {
    global $user;
    if (!$user->uid) {
      $languages = language_list('enabled');
      $languages = $languages[1];
      $query_param = check_plain(variable_get('locale_language_negotiation_session_param', 'language'));
      $query_value = isset($_GET[$query_param]) ? check_plain($_GET[$query_param]) : NULL;
      $query_rewrite = isset($languages[$query_value]) && language_negotiation_get_any(LOCALE_LANGUAGE_NEGOTIATION_SESSION);
    }
    else {
      $query_rewrite = FALSE;
    }
  }

  // If the user is anonymous, the user language provider is enabled, and the
  // corresponding option has been set, we must preserve any explicit user
  // language preference even with cookies disabled.
  if ($query_rewrite) {
    if (is_string($options['query'])) {
      $options['query'] = drupal_get_query_array($options['query']);
    }
    if (!isset($options['query'][$query_param])) {
      $options['query'][$query_param] = $query_value;
    }
  }
}