swap out only main menu for logged in users

Question

I found this tutorial online that allows me to have a different menu for logged in and logged out users http://www.wpbeginner.com/wp-themes/how-to-show-different-menus-to-logged-in-users-in-wordpress/

it works great except one thing, it swaps out every menu I have, I just want to to change the main menu in the header, not my sidebar menus as well

Answer 1

You have the elements of the $args array from wp_nav_menu() available. You can use them with the wp_nav_menu_args filter. In your case you probably want to use theme_location or menu. Exemplary usage:

add_filter( 'wp_nav_menu_args', 'check_for_args_element' );
function check_for_args_element( $args ) {
  if ( $args[ 'theme_location' ] == 'main' ) {
    // code
  }
  return $args;
}