- Modified version of patch #32622 by kbahey: added 'site offline/maintenance' feature.

  (Untested because the admin/settings page doesn't work yet.)

includes/common.inc

@@ -252,6 +252,17 @@ function drupal_goto($path = '', $query = NULL, $fragment = NULL) {
   exit();
 }
 
+
+/**
+ * Generates a site offline message
+ */
+function drupal_site_offline() {
+  header('HTTP/1.0 503 Service unavailable');
+  drupal_set_title(t('Site offline'));
+  print theme('maintenance_page', variable_get('site_offline_message',
+    t('%site is currently under maintenance. We should be back shortly. Thank you for your patience.', array('%site' => variable_get('site_name', t('This drupal site'))))));
+}
+
 /**
  * Generates a 404 error if the request can not be handled.
  */

includes/menu.inc

@@ -164,6 +164,7 @@
 define('MENU_FOUND', 1);
 define('MENU_NOT_FOUND', 2);
 define('MENU_ACCESS_DENIED', 3);
+define('MENU_SITE_OFFLINE', 4);
 
 /**
  * @} End of "Menu status codes".
@@ -324,6 +325,10 @@ function menu_set_location($location) {
  * act as if the user were in a different location on the site.
  */
 function menu_execute_active_handler() {
+  if (_menu_site_is_offline()) {
+    return MENU_SITE_OFFLINE;
+  }
+
   $menu = menu_get_menu();
 
   // Determine the menu item containing the callback.
@@ -1040,3 +1045,19 @@ function _menu_build_local_tasks($pid) {
   return $forked;
 }
 
+/**
+ * Returns TRUE if the is offline for maintenance.
+ */
+function _menu_site_is_offline() {
+  // Check if site is set to offline mode
+  if (variable_get('site_offline', 0)) {
+    // Check if the user has administration privileges
+    if (!user_access('administer site configuration')) {
+      // Check if this is an attempt to login
+      if (drupal_get_normal_path($_GET['q']) != 'user/login') {
+        return TRUE;
+      }
+    }
+  }
+  return FALSE;
+}

index.php

@@ -20,6 +20,9 @@
   case MENU_ACCESS_DENIED:
     drupal_access_denied();
     break;
+  case MENU_SITE_OFFLINE:
+    drupal_site_offline();
+    break;
   default:
     if (!empty($return)) {
       print theme('page', $return);

modules/system.module

@@ -412,6 +412,29 @@ function system_view_general() {
   );
 
 
+  // Site offline/maintenance settings
+  $form['site_status'] = array(
+    type => 'fieldset',
+    title => t('Site maintenance'),
+    collapsible => TRUE,
+    collapsed => TRUE);
+
+  $form['site_status']['site_offline'] = array(
+    type => 'radios',
+    title => t('Site status'),
+    default_value => variable_get('site_offline', 0),
+    options => array(t('Online'), t('Offline')),
+    description => t('When set to "Online", all visitors will be able to browse your site normally. When set to "Offline", only users with the "administer site configuration" permission will be able to access your site to perform maintenance, all other visitors will see the site offline message configured below.')
+  );
+
+  $form['site_status']['site_offline_message'] = array(
+    type => 'textarea',
+    rows => 5,
+    title => t('Site offline message'),
+    default_value => variable_get('site_offline_message', t('%site is currently under maintenance. We should be back shortly. Thank you for your patience.', array('%site' => variable_get('site_name', t('This drupal site'))))),
+    description => t('Message to show visitors when site is offline.')
+  );
+
   // String handling: report status and errors.
   $form['strings'] = array(type => 'fieldset', title => t('String handling'), collapsible => TRUE, collapsed => TRUE);
   $form['strings'] = array_merge($form['strings'], unicode_settings());
@@ -638,7 +661,7 @@ function system_settings_form($form_id, $form) {
   $form['buttons']['reset'] = array(type => 'submit', value => t('Reset to defaults') );
 
   if (!empty($_POST) && form_get_errors()) {
-    drupal_set_message(t('Your settings are not saved because of the errors above'), 'error');
+    drupal_set_message(t('The settings have not been saved because of the errors.'), 'error');
   }
 
   return drupal_get_form($form_id, $form, 'system_settings_form');

modules/system/system.module

@@ -412,6 +412,29 @@ function system_view_general() {
   );
 
 
+  // Site offline/maintenance settings
+  $form['site_status'] = array(
+    type => 'fieldset',
+    title => t('Site maintenance'),
+    collapsible => TRUE,
+    collapsed => TRUE);
+
+  $form['site_status']['site_offline'] = array(
+    type => 'radios',
+    title => t('Site status'),
+    default_value => variable_get('site_offline', 0),
+    options => array(t('Online'), t('Offline')),
+    description => t('When set to "Online", all visitors will be able to browse your site normally. When set to "Offline", only users with the "administer site configuration" permission will be able to access your site to perform maintenance, all other visitors will see the site offline message configured below.')
+  );
+
+  $form['site_status']['site_offline_message'] = array(
+    type => 'textarea',
+    rows => 5,
+    title => t('Site offline message'),
+    default_value => variable_get('site_offline_message', t('%site is currently under maintenance. We should be back shortly. Thank you for your patience.', array('%site' => variable_get('site_name', t('This drupal site'))))),
+    description => t('Message to show visitors when site is offline.')
+  );
+
   // String handling: report status and errors.
   $form['strings'] = array(type => 'fieldset', title => t('String handling'), collapsible => TRUE, collapsed => TRUE);
   $form['strings'] = array_merge($form['strings'], unicode_settings());
@@ -638,7 +661,7 @@ function system_settings_form($form_id, $form) {
   $form['buttons']['reset'] = array(type => 'submit', value => t('Reset to defaults') );
 
   if (!empty($_POST) && form_get_errors()) {
-    drupal_set_message(t('Your settings are not saved because of the errors above'), 'error');
+    drupal_set_message(t('The settings have not been saved because of the errors.'), 'error');
   }
 
   return drupal_get_form($form_id, $form, 'system_settings_form');