CodeGurus

/**
 * WP_nav_menu separate submenu output.
 *
 * Optional $args contents:
 *
 * string theme_location - The menu that is desired.  Accepts (matching in order) id, slug, name. Defaults to blank.
 * string xpath - Optional. xPath syntax.
 * string before - Optional. Text before the menu tree.
 * string after - Optional. Text after the menu tree.
 * bool echo - Optional, default is TRUE. Whether to echo the menu or return it.
 *
 * @author Tauno Hanni
 * @param array $args Arguments
 * @return String If $echo value is set to FALSE.
 */
function px_the_submenu( $args = array() )
{

	$defaults = array(
		'theme_location' => '',
		'xpath' => "./li[contains(@class,'current-menu-item') or contains(@class,'current-menu-ancestor')]/ul",
		'before' => '',
		'after' => '',
		'echo' => true
	);
	$args = wp_parse_args( $args, $defaults );
	$args = (object) $args;

	$output = array();

	$menu_tree = wp_nav_menu( array( 'theme_location' => $args->theme_location, 'container' => '', 'echo' => false ) );
	$menu_tree_XML = new SimpleXMLElement( $menu_tree );
	$path = $menu_tree_XML->xpath( $args->xpath );

	$output[] = $args->before;

	if( ! empty( $path ) )
	{
		$output[] = $path[0]->asXML();
	}

	$output[] = $args->after;

	if( $args->echo )
		echo implode('', $output );
	else
		return implode('', $output );

}