Drupal 7: Invoking Custom Callback in Maintenance Mode

Custom Callback in Drupal 7

In a Drupal site, if we have any module upgrade or configuration-related work to be done in our live site, it is recommended to put the site in maintenance mode, so we can prevent end-users from experiencing glitches.

When the site is operating in maintenance mode, any page request would return only a maintenance message. Some pages are allowed to access though. The login functionality for instance will work in the maintenance mode. Recently, I faced such requirements in which a custom module's callback to be invoked as to let Single Sign On (SSO) work for admin in maintenance mode. I would like to explain the way I fixed the same in this blog.

There is a hook in Drupal 7 for that, hook_menu_site_status_alter(). With this hook we can control the site status before menu dispatching, So we can change the site status for the particular path.

function MY_MODULE_menu_site_status_alter(&$menu_site_status, $path) {
  if ($path == 'my_module/authentication') {
    $menu_site_status = MENU_SITE_ONLINE;
  }
}

Now the my_module/authentication path will be working in the site maintenance mode.