class pages_from_nav extends Walker_Nav_Menu
{
function start_el(&$output, $item, $depth, $args)
{
$parentPageID = get_the_ID();
global $wp_query;
if ($item->post_parent == $parentPageID) {
$item_output .= $item->object_id;
$item_output .= ",";
}
$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}
}
function jawonio_pages_from_nav() {
wp_nav_menu(array(
'menu' => 'Main Navigation',
'container' => '',
'menu_id' => 'site-nav',
'depth' => 0,
'walker' => new pages_from_nav()
));
}