Support hook_suppress() to hide the navbar

This patch adds support for hook_suppress().

Here is revised patch against the current dev branch.

I think that if someone calls the hook_suppress they don't want to display the unneeded JS either. This is the same way that hook_suppress is implemented in admin_menu.

I'll get this in. Thanks for the patch!

+++ b/navbar.moduleundefined
@@ -123,3 +126,26 @@ function navbar_view() {
+/**
+ * Implementation of hook_suppress()
+ *
+ * Allows other modules to suppress display of Navbar
+ *
+ * This function should be called from within another module's page callback
+ * (preferably using module_invoke()) when the menu should not be displayed.
+ * This is useful for modules that implement popup pages or other special
+ * pages where the chat would be distracting or break the layout.
+ *
+ * @param $set
+ *   Defaults to TRUE. If called before hook_footer(), the navbar will not be
+ *   displayed. If FALSE is passed, the suppression state is returned.
+ **/
+function navbar_suppress($set = TRUE) {
+  static $suppress = FALSE;
+  if (!empty($set) && $suppress === FALSE) {
+    $suppress = TRUE;
+	drupal_add_js(array('navbar' => array('suppress' => 1)), 'setting');
+  }
+  return $suppress;

I don't understand. If I pass FALSE, as in I don't want the navbar to be supressed, then $suppress will be set to TRUE and the JS navbar behaviors will be aborted, but the Navbar HTML will still be outputed?

And if I pass TRUE, as in I want to suppress the navbar, then nothing is suppressed and the Navbar behaviors are run?

Also, if we suppress the navbar at during the render stage, let's say in pre_render, we won't need to knock out the JS because it just won't be loaded.

Dave Reid, I don't quite follow. Is the point of hook_shutdown to completely prevent a module from adding to the render pipeline? Should we use hook_shutdown or hook_suppress?

I far as I understand, you end up delivering all the JS/CSS assets to the client and none of the HTML. I can't see a use case for this. Why would someone want to suppress output from any modules that happen to have this hook? It seems like you'd end up with a swiss-cheese page.

I fixed the issue summary to say hook_suppress() rather than hook_shutdown(). This hook should not be needed in D8, because there should be better ways of controlling what does/doesn't get rendered in different conditions. This issue is filed for 7.x-1.x though, and for that, it seems reasonable.

Rerolled patch against current dev

+++ b/navbar.module
@@ -961,3 +964,26 @@ function navbar_convert_libraries_to_library($library, $options) {
+ drupal_add_js(array('navbar' => array('suppress' => 1)), 'setting');

Indentation is all wrong.

Updated patch attached (though have found that Navbar broken in other ways atm)

I took out the JavaScript code because these assets are not loaded if the Navbar element isn't placed in the render tree. So there's no need to alter the JS behavior.

Is that sufficient for what you need?

Added in e3389576b2539d79d9546b6fbd9b35ddd37c98fd

Just for the record.

Admin menu module adds a JS setting in their hook_suppress, because admin_menu implements a special AJAX client-side caching . (Admin menu markup doesn't re-generate every page load).

Originally hook_suppress didn't have the JS setting, it was only added later on, with this feature #345984: Client-side caching of administration menu