Add a Custom Menu Panel with Easy Digital Download Pages | http://www.ibenic.com/custom-menu-panel-edd-pages

metabox.php

<?php

add_action( 'load-nav-menus.php', 'ibenic_add_edd_menu_panel' );

/**
* Adding the menu panel metabox 
*/
function ibenic_add_edd_menu_panel() {
	add_meta_box( 
		'edd-menu-panel', 
		__( 'Easy Digital Downloads', 'edd-menu-panel' ), // Menu Panel Title
		'ibenic_render_edd_menu_panel', // Rendering Function, HTML
		'nav-menus', 
		'side', 
		'default');
}

render_function.php

<?php

function ibenic_render_edd_menu_panel() {
	global $nav_menu_selected_id; // The current menu selected ID

	$walker = new EDD_Menu_Panel_Walker( false ); // Custom Walker
  
	$args   = array( 'walker' => $walker ); // Arguments for the Walker

	$edd_pages = array();
  
  // Here we will define our pages
 
	$edd_pages = apply_filters( 'edd_menu_panel_pages', $edd_pages );
	
	?>
  <!-- Custom Panel with id #edd-menu-panel -->
	<div id="edd-menu-panel" class="posttypediv">
		<p><?php _e( '<em>Links defined in Easy Digital Downloads Settings</em>', 'edd-menu-panel' ); ?></p>
    <!-- Holding the Pages -->
		<div id="tabs-panel-posttype-edd-menu" class="tabs-panel tabs-panel-active">
			<ul id="edd-menu-checklist-loggedin" class="categorychecklist form-no-clear">
        <!-- Walker -->
				<?php echo walk_nav_menu_tree( array_map( 'wp_setup_nav_menu_item', $edd_pages ), 0, (object) $args );?>
			</ul>
		</div>
    
    
		<?php
		$removed_args = array(
			'action',
			'customlink-tab',
			'edit-menu-item',
			'menu-item',
			'page-tab',
			'_wpnonce',
		);
		?>

		<p class="button-controls">
			<span class="list-controls">
        <!-- Adding a Select All option -->
				<a href="<?php
				echo esc_url( add_query_arg(
					array(
						'edd-menu-tab' => 'all',
						'selectall'              => 1,
					),
					remove_query_arg( $removed_args )
				) );
				?>#edd-menu-panel" class="select-all"><?php _e( 'Select All', 'edd-menu-panel' ); ?></a>
			</span>
			<span class="add-to-menu">
				<input type="submit"<?php if ( function_exists( 'wp_nav_menu_disabled_check' ) ) : wp_nav_menu_disabled_check( $nav_menu_selected_id ); endif; ?> class="button-secondary submit-add-to-menu right" value="<?php esc_attr_e( 'Add to Menu', 'edd-menu-panel' ); ?>" name="add-custom-menu-item" id="submit-edd-menu-panel" />
				<span class="spinner"></span>
			</span>
		</p>
	</div><!-- /#buddypress-menu -->
	<?php
}
 

render_function2.php

<?php

// ...

$edd_pages = array();

$edd_checkout = edd_get_option( 'purchase_page' );

if( $edd_checkout ) {
  $page = get_post( $edd_checkout );
  $edd_pages[ $page->post_name ] = $page;
}

$edd_success = edd_get_option( 'success_page' );

if( $edd_success ) {
  $page = get_post( $edd_success );
  $edd_pages[ $page->post_name ] = $page;
}

$edd_failed = edd_get_option( 'failure_page' );

if( $edd_failed ) {
  $page = get_post( $edd_failed );
  $edd_pages[ $page->post_name ] = $page;
}

$edd_history = edd_get_option( 'purchase_history_page' );

if( $edd_history ) {
  $page = get_post( $edd_history );
  $edd_pages[ $page->post_name ] = $page;
}

$edd_login_redirect = edd_get_option( 'login_redirect_page' );

if( $edd_login_redirect ) {
  $page = get_post( $edd_login_redirect );
  $edd_pages[ $page->post_name ] = $page;
}

$edd_pages = apply_filters( 'edd_menu_panel_pages', $edd_pages );

// ...

walker.php

<?php

/**
 * Custom Walker for EDD Pages
 */

class EDD_Menu_Panel_Walker extends Walker_Nav_Menu {

	/**
	 * Create the markup to start an element.
	 *
	 * @see Walker::start_el() for description of parameters.
	 *
	 * @param string       $output Passed by reference. Used to append additional
	 *                             content.
	 * @param object       $item   Menu item data object.
	 * @param int          $depth  Depth of menu item. Used for padding.
	 * @param object|array $args   See {@Walker::start_el()}.
	 * @param int          $id     See {@Walker::start_el()}.
	 */
	function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
		global $_nav_menu_placeholder;

		$_nav_menu_placeholder = ( 0 > $_nav_menu_placeholder ) ? intval($_nav_menu_placeholder) - 1 : -1;
		$possible_object_id = isset( $item->post_type ) && 'nav_menu_item' == $item->post_type ? $item->object_id : $_nav_menu_placeholder;
		$possible_db_id = ( ! empty( $item->ID ) ) && ( 0 < $possible_object_id ) ? (int) $item->ID : 0;

		$indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

		$output .= $indent . '<li>';
		$output .= '<label class="menu-item-title">';
		$output .= '<input type="checkbox" class="menu-item-checkbox';

		if ( property_exists( $item, 'label' ) ) {
			$title = $item->label;
		}

		$output .= '" name="menu-item[' . $possible_object_id . '][menu-item-object-id]" value="'. esc_attr( $item->object_id ) .'" /> ';
		$output .= isset( $title ) ? esc_html( $title ) : esc_html( $item->title );
		$output .= '</label>';

		if ( empty( $item->url ) ) {
			$item->url = $item->guid;
		}

		if ( ! in_array( array( 'edd-menu', 'edd-'. $item->post_name .'-nav' ), $item->classes ) ) {
			$item->classes[] = 'edd-menu';
			$item->classes[] = 'edd-'. $item->post_name .'-nav';
		}

		// Menu item hidden fields.
		$output .= '<input type="hidden" class="menu-item-db-id" name="menu-item[' . $possible_object_id . '][menu-item-db-id]" value="' . $possible_db_id . '" />';
		$output .= '<input type="hidden" class="menu-item-object" name="menu-item[' . $possible_object_id . '][menu-item-object]" value="'. esc_attr( $item->object ) .'" />';
		$output .= '<input type="hidden" class="menu-item-parent-id" name="menu-item[' . $possible_object_id . '][menu-item-parent-id]" value="'. esc_attr( $item->menu_item_parent ) .'" />';
		$output .= '<input type="hidden" class="menu-item-type" name="menu-item[' . $possible_object_id . '][menu-item-type]" value="'. esc_attr( $item->type ) .'" />';
		$output .= '<input type="hidden" class="menu-item-title" name="menu-item[' . $possible_object_id . '][menu-item-title]" value="'. esc_attr( $item->title ) .'" />';
		$output .= '<input type="hidden" class="menu-item-url" name="menu-item[' . $possible_object_id . '][menu-item-url]" value="'. esc_attr( $item->url ) .'" />';
		$output .= '<input type="hidden" class="menu-item-target" name="menu-item[' . $possible_object_id . '][menu-item-target]" value="'. esc_attr( $item->target ) .'" />';
		$output .= '<input type="hidden" class="menu-item-attr_title" name="menu-item[' . $possible_object_id . '][menu-item-attr_title]" value="'. esc_attr( $item->attr_title ) .'" />';
		$output .= '<input type="hidden" class="menu-item-classes" name="menu-item[' . $possible_object_id . '][menu-item-classes]" value="'. esc_attr( implode( ' ', $item->classes ) ) .'" />';
		$output .= '<input type="hidden" class="menu-item-xfn" name="menu-item[' . $possible_object_id . '][menu-item-xfn]" value="'. esc_attr( $item->xfn ) .'" />';
	}
}