Move custom post menu to under plugin admin menu

Question

I have a custom plugin with a set of menus. I also have working a custom post type, but I am not sure how to push the custom post under the plugin's admin menu item.

The code for the custom post, with taxonomies is as follows:

function mmd_list_admin_manualentry() {
  $labels = array(
    'name'               => _x( 'Manage Lists', 'mmd_list' ),
    'singular_name'      => _x( 'Manage List', 'mmd_lists' ),
    'add_new'            => _x( 'New List', 'mmd_list' ),
    'add_new_item'       => __( 'Add New List' ),
    'edit_item'          => __( 'Edit List' ),
    'new_item'           => __( 'New List' ),
    'all_items'          => __( 'Manage Lists' ),
    'view_item'          => __( 'View List' ),
    'search_items'       => __( 'Search List' ),
    'not_found'          => __( 'No Listing found' ),
    'not_found_in_trash' => __( 'No Listings found in the Trash' ), 
    'parent_item_colon'  => '',
    'menu_name'          => 'CUSTOM POST TEST'
   );

  $args = array(
  'labels'        => $labels,
  'description'   => 'This post type holds all posts for your directory items.',
  'public'        => true,
  'menu_position' => 10,
  'show_ui'       => true,
  'show_in_menu'  => 'mmd_list_options',           // Use the plugin menu slug
  'supports'      => array( 'title' ),
  'has_archive'   => true,
  );
  register_post_type( 'mmd_list', $args ); 
}
add_action( 'init', 'mmd_list_admin_manualentry', 0 );


function mmd_list_taxonomies() {
  $labels = array(
        'name'              => _x( 'List Categories', 'List Categories' ),
        'singular_name'     => _x( 'Category', 'taxonomy singular name' ),
        'search_items'      => __( 'Search List Categories' ),
        'all_items'         => __( 'All List Categories' ),
        'parent_item'       => __( 'Parent List Categories' ),
        'parent_item_colon' => __( 'Parent List Category:' ),
        'edit_item'         => __( 'Edit List Category' ),
        'update_item'       => __( 'Update List Category' ),
        'add_new_item'      => __( 'Add New List Category' ),
        'new_item_name'     => __( 'New List Category Name' ),
        'menu_name'         => __( 'List Categories')
  );

$args = array(
    'hierarchical'      => true,
    'labels'            => $labels,
    'show_ui'           => true,
    'show_admin_column' => true,
    'query_var'         => true,
    'rewrite'           => array( 'slug' => 'mmd_list_cat' )
  );

  register_taxonomy( 'mmd_list_cat', 'mmd_list', $args );
}
add_action( 'init', 'mmd_list_taxonomies', 0 );

add_action( 'add_meta_boxes', 'mmd_listings_add_entryfield' );
function mmd_listings_add_entryfield() 
 {

// add_meta_box( $id, $title, $callback, $page, $context, $priority, $callback_args );  
    add_meta_box( 
        'mmd_listings_List_Group',
        __( 'Manual Entry', 'myplugin_textdomain' ),
        'mmd_listing_EntryForm',
        'mmd_list',
        'normal',
        'high'
    );
}

The code for the standard WordPress plugin is not remarkable.

add_action( 'admin_menu', 'mmd_list_Define_admin_menu' );                        
// Add menu items
function mmd_list_Define_admin_menu()
{
    add_menu_page( 'MMD Lists',                     // The page title.
               'Lists',                         // The menu title displayed on dashboard.
               'manage_options',                       // Minimum capability to view the menu.
               'mmd_list_options',                     // Unique name used as a slug for menu item.
               'mmd_maplist_DrawAdminPage',            // A callback function used to display page content.
               'dashicons-media-spreadsheet',          // URL to custom image used as icon.
               6
               );

add_submenu_page('mmd_list_options',                        // Parent Slug from add_menu_page 
                 'Manage Lists',                            // Title of page
                 'Manage Lists',                            // Menu title
                 'manage_options',                          // Minimum capability to view the menu.
                 'mmd_manage_lists_slug',                   // Unqiue Slug Name
                 '' );            // Custom Post menu.


}                    

I am just not sure how to get the custom post to fall under the plugin admin menu WITH all of its submenus including: categories, Manage List, Add List and proper post pages etc.

I have tried various assignments, including leaving the submenu call back function blank and references it with the slug name in the post registration, but that just leads to a "unknown page 404" code. If I use the main menu page and use that name, yes the custom post single menu item comes up, but I do not have access to the admin page I need for the plugin.

Been all over the function reference. There just does not seem to be the equivalent of a "parent" like in the admin menus. https://codex.wordpress.org/Function_Reference/register_post_type

Been scouring the web and the subject is either post-type or plugin type, not a blending of both.

Any thoughts on this?

Answer 1

Well it took me a while, but my solution was to reverse it. Use the custom post the primary admin menu option and then you can add a standard admin page as a submenu by doing the following:

  $labels = array(
    'name'               => _x( 'Manage Lists', 'mmd_list' ),
    'singular_name'      => _x( 'Manage List', 'mmd_lists' ),
    'add_new'            => _x( 'New List', 'mmd_list' ),
    'add_new_item'       => __( 'Add New List' ),
    'edit_item'          => __( 'Edit List' ),
    'new_item'           => __( 'New List' ),
    'all_items'          => __( 'Manage Lists' ),
    'view_item'          => __( 'View List' ),
    'search_items'       => __( 'Search List' ),
    'not_found'          => __( 'No Listing found' ),
    'not_found_in_trash' => __( 'No Listings found in the Trash' ), 
    'parent_item_colon'  => '',
    'menu_name'          => 'Lists'
   );
  $args = array(
      'labels'        => $labels,
      'description'   => 'This post type holds all posts for your directory items.',
      'public'        => true,
      'menu_position' => 10,
      'show_ui'       => true,
      'supports'      => array( 'title' ),
      'has_archive'   => true,
      'menu_icon'   => 'dashicons-media-spreadsheet',
      );
  register_post_type( 'mmd_list', $args ); 


add_submenu_page('edit.php?post_type=mmd_list',             // Parent Slug from 
add_menu_page 
             'Settings',                     // Title of page
             'Settings',                     // Menu title
             'manage_options',               // Minimum capability to view the menu.
             'mmd_list_options_slug',        // Unqiue Slug Name
             'mmd_maplist_DrawAdminPage' );  // A callback function used 
to display page content.

The key is to swap out the parent slug for the custom post type: edit.php?post_type="Your Post Type"