Render Menu

function.php

<?php

/**
 * Render_Menu
 * -----------------
 * Render a menu using simple, semantic HTML
 *
 * Usage: new Render_Menu(@name)
 *
 * @name (string) name of the menu ("main-navigation")
 *
 * Output:
 * <ul>
 *   <li><a href="/home">Home</a>
 *   <li><a href="/mission">Our Mission</a>
 *   <li class="has-self"><a href="/team">Our Team</a>
 *     <ul class="has-self">
 *       <li><a href="/team/jonathan">Jonathan</a>
 *       <li class="self"><a href="/team/christina">Christina</a>
 *     </ul>
 * </ul>
 */

class Render_Menu {
	function __construct($menu_name) {
		// get the id of the current document
		$currentId = get_queried_object_id();

		if (($locations = get_nav_menu_locations()) && isset($locations[$menu_name])) {
			// get the menu
			$menu = wp_get_nav_menu_object($locations[$menu_name]);

			// get all of the menu items
			$menu_items = wp_get_nav_menu_items($menu->term_id, 0);

			// create an empty array
			$menu_array = array();

			// loop through all of the menu items
			foreach ((array) $menu_items as $key => $menu_item) {
				// if the menu item is top level
				if ($menu_item->menu_item_parent == 0) {
					$menu_array[$menu_item->ID] = $menu_item;
				} else {
					// if the menu item's parent does not yet have an array for children
					if (!isset($menu_array[$menu_item->menu_item_parent]->children)) {
						$menu_array[$menu_item->menu_item_parent]->children = array();
					}

					// push the menu item to the parent's array for children
					array_push($menu_array[$menu_item->menu_item_parent]->children, $menu_item);
				}

				// assign whether the menu item represents the current document
				$menu_item->is_self = $menu_item->object_id == $currentId;

				// if the menu item represents the current document
				if ($menu_item->is_self) {
					// while menu_item exists
					while ($menu_item) {
						// assign the menu as either representing or containing the representative of the current document
						$menu_item->has_self = true;

						// assign menu_item as its parent
						$menu_item = $menu_array[$menu_item->menu_item_parent];
					}
				}
			}

			print($this->render($menu_array));
		}
	}

	function render($menu_items, $has_self = false) {
		$buffer = '<ul'.($has_self ? ' class="has-self"' : '').'>';

		foreach ((array) $menu_items as $menu_item) {
			$buffer.= '<li'.($menu_item->is_self ? ' class="self"' : ($menu_item->has_self ? ' class="has-self"' : '')).'>';
			$buffer.= '<a href="'.$menu_item->url.'">'.$menu_item->title.'</a>';

			$buffer.= $menu_item->children ? $this->render($menu_item->children, $menu_item->has_self) : '';
		}

		$buffer.='</ul>';

		return $buffer;
	}
}