function _drupal_maintenance_theme

Sets up the theming system for maintenance page.

Used for site installs, updates and when the site is in maintenance mode. It also applies when the database is unavailable or bootstrap was not complete. Seven is always used for the initial install and update operations. In other cases, Bartik is used, but this can be overridden by setting a "maintenance_theme" key in the $conf variable in settings.php.

File

drupal/core/includes/theme.maintenance.inc, line 17

Theming for maintenance pages.

Code

function _drupal_maintenance_theme() {
  global $theme, $theme_key, $conf;

  // If $theme is already set, assume the others are set too, and do nothing.
  if (isset($theme)) {
    return;
  }
  require_once DRUPAL_ROOT . '/' . variable_get('path_inc', 'core/includes/path.inc');
  require_once DRUPAL_ROOT . '/core/includes/theme.inc';
  require_once DRUPAL_ROOT . '/core/includes/common.inc';
  require_once DRUPAL_ROOT . '/core/includes/unicode.inc';
  require_once DRUPAL_ROOT . '/core/includes/file.inc';
  require_once DRUPAL_ROOT . '/core/includes/module.inc';
  unicode_check();

  // Install and update pages are treated differently to prevent theming overrides.
  if (defined('MAINTENANCE_MODE') && (MAINTENANCE_MODE == 'install' || MAINTENANCE_MODE == 'update')) {
    $custom_theme = isset($conf['maintenance_theme']) ? $conf['maintenance_theme'] : 'seven';
  }
  else {

    // The bootstrap was not complete. So we are operating in a crippled
    // environment, we need to bootstrap just enough to allow hook invocations
    // to work. See _drupal_log_error().
    if (!class_exists('Drupal\\Core\\Database\\Database', FALSE)) {
      require_once DRUPAL_ROOT . '/core/includes/database.inc';
    }

    // We use the default theme as the maintenance theme. If a default theme
    // isn't specified in the database or in settings.php, we use Bartik.
    // @todo Should use the actual default theme configured, but that depends on
    //   configuration being available while possibly not having a working
    //   database connection (yet). And only if that fails, should fall back to
    //   Stark otherwise. Since there is no low-level access to configuration
    //   currently, we only consult settings.php and fall back to Bartik
    //   otherwise, as it looks generic enough and way more user-friendly.
    $custom_theme = variable_get('maintenance_theme', variable_get('theme_default', 'bartik'));
  }

  // Ensure that system.module is loaded.
  if (!function_exists('_system_rebuild_theme_data')) {
    $module_list['system']['filename'] = 'core/modules/system/system.module';
    module_list(NULL, $module_list);
    drupal_load('module', 'system');
  }
  $themes = list_themes();

  // list_themes() triggers a drupal_alter() in maintenance mode, but we can't
  // let themes alter the .info data until we know a theme's base themes. So
  // don't set global $theme until after list_themes() builds its cache.
  $theme = $custom_theme;

  // Store the identifier for retrieving theme settings with.
  $theme_key = $theme;

  // Find all our ancestor themes and put them in an array.
  $base_theme = array();
  $ancestor = $theme;
  while ($ancestor && isset($themes[$ancestor]->base_theme)) {
    $base_theme[] = $new_base_theme = $themes[$themes[$ancestor]->base_theme];
    $ancestor = $themes[$ancestor]->base_theme;
  }
  _drupal_theme_initialize($themes[$theme], array_reverse($base_theme), '_theme_load_offline_registry');

  // These are usually added from system_init() -except maintenance.css.
  // When the database is inactive it's not called so we add it here.
  $path = drupal_get_path('module', 'system');
  drupal_add_css($path . '/system.base.css');
  drupal_add_css($path . '/system.admin.css');
  drupal_add_css($path . '/system.theme.css');
  drupal_add_css($path . '/system.maintenance.css');
}