How can i automatically add CPT single pages as sub menu items

Question

is there any way to setup wordpress so that when I create a CPT and then have a menu item (preferably the archive page) that will automatically create a dropdown of all the actual posts and the links will be to the CPT single pages?

so for instance if i had stores as my CPT the menu would look like this:

Stores (to archive page)

• location 1(to location 1 single)

• location 2(to location 2 single)

• location 3(to location 3 single)

and then if i add a new store location a new link would be created in this menu that would go to location 4(to location single)

my custom post type is currently created by a custom plugin so i would be interested in adding the code to there if possible. I saw another question that said i may have to use wp_nav_menu but i'm not sure where to start with that.

Answer 1

This should work:

add_filter( 'wp_get_nav_menu_items', 'cpt_locations_filter', 10, 3 );

function cpt_locations_filter( $items, $menu, $args ) {
  $child_items = array(); 
  $menu_order = count($items); 
  $parent_item_id = 0;

  foreach ( $items as $item ) {
    if ( in_array('locations-menu', $item->classes) ){ //add this class to your menu item
        $parent_item_id = $item->ID;
    }
  }

  if($parent_item_id > 0){

      foreach ( get_posts( 'post_type=cpt-post-type-here&numberposts=-1' ) as $post ) {
        $post->menu_item_parent = $parent_item_id;
        $post->post_type = 'nav_menu_item';
        $post->object = 'custom';
        $post->type = 'custom';
        $post->menu_order = ++$menu_order;
        $post->title = $post->post_title;
        $post->url = get_permalink( $post->ID );
        array_push($child_items, $post);
      }

  }

  return array_merge( $items, $child_items );
}

Answer 2

Did you tried with "" at the bottom of the menu page. It add's any post or page automatically to menu even if it is custom. I just have no idea about adding it to submenu.