The Problem with your code is that its not actually adding the links to the menu and only to the menu's output, hence the use of a filter (add_filter) so you are just filtering the output of the menu in fact even if you don't have a menu your link will be shown with the code you are using. But to create a link and add it to a menu you can use this code:
$run_once = get_option('menu_check'); if (!$run_once){ //give your menu a name $name = 'theme default menu'; //create the menu $menu_id = wp_create_nav_menu($name); //then get the menu object by its name $menu = get_term_by( 'name', $name, 'nav_menu' ); //then add the actuall link/ menu item and you do this for each item you want to add wp_update_nav_menu_item($menu->term_id, 0, array( 'menu-item-title' => __('Home'), 'menu-item-classes' => 'home', 'menu-item-url' => home_url( '/' ), 'menu-item-status' => 'publish')); //then you set the wanted theme location $locations = get_theme_mod('nav_menu_locations'); $locations['main-menu'] = $menu->term_id; set_theme_mod( 'nav_menu_locations', $locations ); // then update the menu_check option to make sure this code only runs once update_option('menu_check', true); }
I commented all over to make it simpler.
To create a child page/sub page/second level menu (how ever you may call it), you just need to set the menu-item-parent-id in the new item for example:
//create the top level menu item (home) $top_menu = wp_update_nav_menu_item($menu->term_id, 0, array( 'menu-item-title' => __('Home'), 'menu-item-classes' => 'home', 'menu-item-url' => home_url( '/' ), 'menu-item-status' => 'publish' 'menu-item-parent-id' => 0, )); //Sub menu item (first child) $first_child = wp_update_nav_menu_item($menu->term_id, 0, array( 'menu-item-title' => __('First_Child'), 'menu-item-classes' => 'home', 'menu-item-url' => home_url( '/' ), 'menu-item-status' => 'publish' 'menu-item-parent-id' => $top_menu, )); //Sub Sub menu item (first child) $Second_child = wp_update_nav_menu_item($menu->term_id, 0, array( 'menu-item-title' => __('Second_Child'), 'menu-item-classes' => 'home', 'menu-item-url' => home_url( '/' ), 'menu-item-status' => 'publish' 'menu-item-parent-id' => $first_child, ));
also you can set the position by code with menu-item-position and i think its done like this:
- First item - 'menu-item-position' => 1
- First item first child - 'menu-item-position' => 1
- First item second child - 'menu-item-position' => 1
- First item second child first child - 'menu-item-position' => 1
- Second item - 'menu-item-position' => 2
- 3rd item - 'menu-item-position' => 3
- 4th item - 'menu-item-position' => 4