The variables array generated here is a mirror of template_preprocess_page(). This preprocessor will run its course when theme_maintenance_page() is invoked.
An alternate template file of "maintenance-page--offline.tpl.php" can be used when the database is offline to hide errors and completely replace the content.
The $variables array contains the following arguments:
function template_preprocess_maintenance_page(&$variables) {
global $theme;
$language_interface = language(LANGUAGE_TYPE_INTERFACE);
// Retrieve the theme data to list all available regions.
$theme_data = list_themes();
$regions = $theme_data[$theme]->info['regions'];
// Add favicon
if (theme_get_setting('toggle_favicon')) {
$favicon = theme_get_setting('favicon');
$type = theme_get_setting('favicon_mimetype');
drupal_add_html_head_link(array(
'rel' => 'shortcut icon',
'href' => drupal_strip_dangerous_protocols($favicon),
'type' => $type,
));
}
// Get all region content set with drupal_add_region_content().
foreach (array_keys($regions) as $region) {
// Assign region to a region variable.
$region_content = drupal_get_region_content($region);
isset($variables[$region]) ? $variables[$region] .= $region_content : ($variables[$region] = $region_content);
}
// Setup layout variable.
$variables['layout'] = 'none';
if (!empty($variables['sidebar_first'])) {
$variables['layout'] = 'first';
}
if (!empty($variables['sidebar_second'])) {
$variables['layout'] = $variables['layout'] == 'first' ? 'both' : 'second';
}
$site_config = config('system.site');
$site_name = $site_config
->get('name');
$site_slogan = $site_config
->get('slogan');
// Construct page title
if (drupal_get_title()) {
$head_title = array(
'title' => strip_tags(drupal_get_title()),
'name' => check_plain($site_name),
);
}
else {
$head_title = array(
'name' => check_plain($site_name),
);
if ($site_slogan) {
$head_title['slogan'] = strip_tags(filter_xss_admin($site_slogan));
}
}
$variables['head_title_array'] = $head_title;
$variables['head_title'] = implode(' | ', $head_title);
$variables['base_path'] = base_path();
$variables['front_page'] = url();
$variables['breadcrumb'] = '';
$variables['feed_icons'] = '';
$variables['help'] = '';
$variables['language'] = $language_interface;
$variables['language']->dir = $language_interface->direction ? 'rtl' : 'ltr';
$variables['logo'] = theme_get_setting('logo');
$variables['messages'] = $variables['show_messages'] ? theme('status_messages') : '';
$variables['main_menu'] = array();
$variables['secondary_menu'] = array();
$variables['site_name'] = theme_get_setting('toggle_name') ? check_plain($site_name) : '';
$variables['site_slogan'] = theme_get_setting('toggle_slogan') ? filter_xss_admin($site_slogan) : '';
$variables['tabs'] = '';
$variables['title'] = drupal_get_title();
// Compile a list of classes that are going to be applied to the body element.
$variables['attributes']['class'][] = 'in-maintenance';
if (isset($variables['db_is_active']) && !$variables['db_is_active']) {
$variables['attributes']['class'][] = 'db-offline';
}
if ($variables['layout'] == 'both') {
$variables['attributes']['class'][] = 'two-sidebars';
}
elseif ($variables['layout'] == 'none') {
$variables['attributes']['class'][] = 'no-sidebars';
}
else {
$variables['attributes']['class'][] = 'one-sidebar';
$variables['attributes']['class'][] = 'sidebar-' . $variables['layout'];
}
// Dead databases will show error messages so supplying this template will
// allow themers to override the page and the content completely.
if (isset($variables['db_is_active']) && !$variables['db_is_active']) {
$variables['theme_hook_suggestion'] = 'maintenance_page__offline';
}
}