Loader That assists with adding admin bars menus to a WordPress website.

composer require underpin/loaders--admin-bar-menus

This plugin uses a built-in autoloader, so as long as it is required before Underpin, it should work as-expected.

require_once(__DIR__ . '/underpin-admin-bar-menus/underpin-admin-bar-menus.php');

1. Install Underpin. See Underpin Docs
2. Register new admin menus as-needed.

A very basic example could look something like this.

\Underpin\underpin()->admin_bar_menus()->add( 'menu_bar_key', [ 'children' => [], 'capability' => 'administrator', 'id' => 'menu_bar_id', // Required 'args' => [ /* See WP_Admin_Bar::add_menu */ ], 'position' => 200, 'name' => 'Menu Bar', 'description' => 'A menu bar example', ] );

Alternatively, you can extend Admin_Bar_Menu and reference the extended class directly, like so:

underpin()->admin_bar_menus()->add('menu_bar-key','Namespace\To\Class');