Customising Primary Nav Menu

Hi Tom,

Thank you for the fantastic GeneratePress WordPress theme. It's clean, easy-to-work with, and has offered a great entry point into WordPress.

Being at that entry point... I've created a child theme for the site I'm working on at http://www.webeatthegame.com/ It's a development site for a gaming... blog? So, I'm slowly building it as I come to terms with the wonders of WordPress actions, classes, hooks, filters, functions, and objects.

Our current problem : We'd like to customise the primary <nav> menu displayed on the page based on :

• Whether a user's logged in
• A user's WordPress role.

A menu has been created in the WordPress Dashboard > Appearance > Menus section for each scenario. i.e. 'public_menu' for users who are not logged in; 'member_menu' for members; and 'admin_menu' for site administrators.

The functions relating to a user being logged in, and WordPress user roles I've got a handle on. Where I'm failing is how to replace the primary <nav> menu in the functions.php file.

I imagine the code will need to look something like this based on my research thus far (this is a basic 'logged in/not logged in example only for simplicity's sake) :

<?php
unregister_nav_menu( 'primary' );

if ( is_user_logged_in() ) {
  register_nav_menu( //some code// );
  wp_nav_menu( array ( 'menu' => 'member_menu' ) );
}
else {
  register_nav_menu( //some code// );
  wp_nav_menu( array ( 'menu' => 'public_menu' ) );
}

If you can offer any assistance, it'd be appreciated!

Regards,
Mark