What corrections does this code need?

Question

I have a function which adds an extra item (and sub-menu items) to the admin bar.

It shows a debug error of... Notice: WP_Admin_Bar::add_node was called incorrectly. The menu ID should not be empty.

function add_admin_bar_menu_misc() {
global $wp_admin_bar;
if ( !is_super_admin() || !is_admin_bar_showing() )
return;

$wp_admin_bar->add_menu( array(
'id' => 'misc',
'title' => 'Misc',
'href' => FALSE ) );

$wp_admin_bar->add_menu( array(
'parent' => 'misc',
'title' => 'Export',
'href' => admin_url('export.php'), ) );

$wp_admin_bar->add_menu( array(
'parent' => 'misc',
'title' => 'Back-up',
'href' => admin_url('admin.php?page=wp-dbmanager%2Fdatabase-    backup.php'), ) );

}
add_action('admin_bar_menu', 'add_admin_bar_menu_misc', 999);

What do I need to do to fix it?

Answer 1

The answer is in the error message:

The menu ID should not be empty.

Notice in the first call there is an id field:

$wp_admin_bar->add_menu( array(
'id' => 'misc',
'title' => 'Misc',
'href' => FALSE ) );

But, in the second and third there is no ID!

$wp_admin_bar->add_menu( array(
'parent' => 'misc',
'title' => 'Export',
'href' => admin_url('export.php'), ) );

$wp_admin_bar->add_menu( array(
'parent' => 'misc',
'title' => 'Back-up',
'href' => admin_url('admin.php?page=wp-dbmanager%2Fdatabase-    backup.php'), ) );

Therefore it is empty, and that is not allowed.

If we look at the official documentation for add_menu we see that id is required and not optional:

https://developer.wordpress.org/reference/classes/wp_admin_bar/add_menu/

We also see that the user notes on that page link to examples on related hooks, and all of them have an id, e.g.

    $wp_admin_bar->add_menu(
        array(
            'parent' => $menu_id,
            'title'  => __( 'Disable', 'text-domain'  ),
            'id'     => 'new-order-notification-disable',
            'href'   => admin_url( 'admin.php?page=custom-submenu-slug' ),

        )
    );