1.12.x admin_bar.module admin_bar_js_cache()
1.10.x admin_bar.module admin_bar_js_cache()
1.11.x admin_bar.module admin_bar_js_cache()
1.7.x admin_bar.module admin_bar_js_cache()

Menu callback; Output administration bar for HTTP caching via AJAX request.

See also



modules/admin_bar/admin_bar.module, line 327
Render an administrative bar as a dropdown menu at the top of the window.


function admin_bar_js_cache() {
  global $conf;

  // Enforce page caching.
  $conf['cache'] = 1;

  // If we have a cache, serve it.
  // @see _backdrop_bootstrap_page_cache()
  $cache = backdrop_page_get_cache();
  if (is_object($cache)) {
    backdrop_add_http_header('X-Backdrop-Cache', 'HIT');

  // Otherwise, create a new page response (that will be cached).
  backdrop_add_http_header('X-Backdrop-Cache', 'MISS');

  // The Expires HTTP header is the heart of the client-side HTTP caching. The
  // additional server-side page cache only takes effect when the client
  // accesses the callback URL again (e.g., after clearing the browser cache or
  // when force-reloading a Backdrop page).
  $max_age = 3600 * 24 * 365;
  backdrop_add_http_header('Expires', gmdate(DATE_RFC1123, REQUEST_TIME + $max_age));
  backdrop_add_http_header('Cache-Control', 'private, max-age=' . $max_age);

  // Retrieve and return the rendered menu.
  module_load_include('inc', 'admin_bar');
  return admin_bar_output();