Custom menus (and much more) for logged in WordPress users

members.php

<?php
/*
Plugin Name: Gallery Members (for wpse32840)
Description: Only allow members to view one page
Author: Christopher Davis
Author URI: http://www.christopherguitar.net/
*/

register_activation_hook( __FILE__, 'wpse32840_activation' );
function wpse32840_activation()
{
	flush_rewrite_rules();
}	

add_action( 'init', 'wpse32840_register_post_type' );
function wpse32840_register_post_type()
{
	register_post_type(
		'client_gallery',
		array(
			'label' 				=> __( 'Client Galleries' ), // probably needs better labels
			'public' 				=> true, // allow people to see this on the front end
			'exclude_from_search'	=> true, // cant be brought up via a search
			'show_in_nav_menus'		=> false, // not in nav menus (we'll do this manually)
			'rewrite'				=> array( 'slug' => 'gallery' )
		)
	);		
}

/**
 * When we register a user, add a 'client_gallery' post
 * If that fails, set the gallery id to 0, so we can set it later.
 */
add_action( 'user_register', 'wpse32840_capture_register' );
function wpse32840_capture_register( $user_id )
{
	$userobj = get_user_by( 'id', $user_id );
	
	$gallery_id = wp_insert_post(
		array(
			'post_type' 	=> 'client_gallery',
			'post_title'	=> sprintf( '%s gallery', $userobj->user_login )
		), 
		true
	);
	
	if( is_wp_error( $gallery_id ) ) $gallery_id = 0;
	
	update_user_meta( $user_id, 'wpse32840_gallery_id', absint( $gallery_id ) );
}

/**
 * We should also be able to give users acces to gallery manually,
 * so let's add some fields to the user profile page
 */
add_action( 'edit_user_profile', 'wpse32840_user_profile' );
function wpse32840_user_profile( $user )
{
	$gallery_id = get_user_meta( $user->ID, 'wpse32840_gallery_id', true );
	
	// get all of our galleries!
	$galleries = get_posts(
		array(
			'post_type' 	=> 'client_gallery',
			'numberposts'	=> -1,
			'post_status'	=> 'any'
		)
	);
	
	// no galleries?  bail.
	if( ! $galleries ) return;
	
	// nonce
	wp_nonce_field( 'wpse32840_nonce', 'wpse32840_nonce', false );
	
	// our fields
	echo '<h3>' . __( 'Gallery' ) . '</h3>';
	echo '<select name="wpse32840_gallery">';
	echo '<option ' . selected( $gallery_id, 0, false ). ' value="0">No gallery</option>';
	foreach( $galleries as $g )
	{
		echo '<option ' . selected( $gallery_id, $g->ID, false ) . ' value="' . absint( $g->ID ) . '">' . esc_html( $g->post_title ) . '</option>';
	}
	echo '</select>';
}

/**
 * Save the user's gallery ID from the user edit page.
 */
add_action( 'edit_user_profile_update', 'wpse32840_save_user' );
function wpse32840_save_user( $user_id )
{
	if( ! isset( $_POST['wpse32840_nonce'] ) || ! wp_verify_nonce( $_POST['wpse32840_nonce'], 'wpse32840_nonce' ) ) 
		return;
	
	if( ! isset( $_POST['wpse32840_gallery' ] ) )
		return;
	
	update_user_meta( $user_id, 'wpse32840_gallery_id', absint( $_POST['wpse32840_gallery'] ) );
}

/**
 * Hook into template redirect to stop normal visitor from accessing galleries
 */
add_action( 'template_redirect', 'wpse32840_check_user' );
function wpse32840_check_user()
{
	// not on a client gallery?  bail
	if( ! is_singular( 'client_gallery' ) ) return;
	
	// is the is an admin?
	if( current_user_can( 'manage_options' ) ) return;
	
	// thrown non logged in users back to the home page
	if( ! is_user_logged_in() )
	{
		wp_redirect( home_url(), 302 );
		exit();
	}
	
	$user = wp_get_current_user();
	$gallery_id = get_queried_object_id();
	
	// if the user isn't an admin or isn't assigned this gallery, send them back to the home page
	if( $gallery_id != get_user_meta( $user->ID, 'wpse32840_gallery_id', true ) )
	{
		wp_redirect( home_url(), 302 );
		exit();
	}
	// By here, the user is authenticated, let them continue on their merry way.
}

/**
 * Filter the nav menu so logged in users only see certain things
 */
add_filter( 'wp_nav_menu_items', 'wpse32840_filter_nav', 10, 2 );
function wpse32840_filter_nav( $items, $args )
{
	/**
	 * you can check for theme location here via $args... check to see if this is the main nav
	 * in twenty eleven, we can check to see if this is the "primary" menu
	 * Other thigns will be different.  If we're not in the primary menu, bail
	 */
	if( 'primary' != $args->theme_location ) return $menu;
	
	// Not logged in?  return the menu
	if( ! is_user_logged_in() ) return $items;
	
	// if this is an admin, return the menu unaltered.
	if( current_user_can( 'manage_options' ) ) return $items;
	
	// our user is logged in an not an admin, build them a new menu
	
	// get our current user
	$user = wp_get_current_user();
	
	// get the users gallery
	$gallery_id = get_user_meta( $user->ID, 'wpse32840_gallery_id', true );
	$gallery = get_post( absint( $gallery_id ) );
	
	$items = '<li class="menu-item"><a href="' . esc_url( home_url() ) . '">Home</a></li>';
	$items .= '<li class="menu-item"><a href="' . esc_url( get_permalink( $gallery ) ) . '">Gallery</a></li>';
	return $items;
}