WordPress automatic submenu plugin

If no submenu item is explicitly set, this plugin automatically adds submenu items if the menu item points to a hierarchical post type.

The plugin acts on all menus and respects the 'depth' option. To disable the plugin for a specific menu, add a filter:

add_filter( 'submenu_3000', 'prefix_filter_submenu_3000', 10, 4 );

/**
 * Only add submenu items to a specific theme location.
 *
 * @param string   $item_output The menu item's starting HTML output.
 * @param WP_Post  $item        Menu item data object.
 * @param int      $depth       Depth of menu item. Used for padding.
 * @param stdClass $args        An object of wp_nav_menu() arguments.
 */
function prefix_filter_submenu_3000( $item_output, $item, $depth, $args ) {

    if ( 'primary' !== $args->theme_location ) {
        return false;
    }
}

Filter CSS classes and link attributes

• Filter the CSS classes for a submenu <ul> element: submenu_3000_submenu_css_class
• Filter he HTML attributes for a submenu
  element: submenu_3000_submenu_attributes
• Filter the CSS classes for a submenu item <li> element: submenu_3000_item_css_class
• Filter the HTML attributes for a submenu item link element: submenu_3000_menu_link_attributes

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