<?php
if ( ! defined( 'ABSPATH' ) ) { exit; }
/**
 * Cleaner walker for wp_nav_menu()
 *
 * Walker_Nav_Menu (WordPress default) example output:
 *   <li id="menu-item-8" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-8"><a href="/">Home</a></li>
 *   <li id="menu-item-9" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-9"><a href="/sample-page/">Sample Page</a></l
 *
 * Roots_Nav_Walker example output:
 *   <li class="menu-home"><a href="/">Home</a></li>
 *   <li class="menu-sample-page"><a href="/sample-page/">Sample Page</a></li>
 */


/**
 * Remove the id="" on nav menu items
 * Return 'menu-slug' for nav menu classes
 */
function roots_nav_menu_css_class($classes, $item)
{
    $slug = sanitize_title($item->title);
    $classes = preg_replace('/(current(-menu-|[-_]page[-_])(item|parent|ancestor))/', 'active', $classes);
    $classes = preg_replace('/^((menu|page)[-_\w+]+)+/', '', $classes);

    $classes[] = 'menu-' . $slug;

    $classes = array_unique($classes);

    return array_filter($classes, 'is_element_empty');
}

function is_element_empty($element) {
	$element = trim($element);
	return empty($element) ? false : true;
}

add_filter('nav_menu_css_class', 'roots_nav_menu_css_class', 10, 2);
add_filter('nav_menu_item_id', '__return_null');

/**
 * Clean up wp_nav_menu_args
 *
 * Remove the container
 * Use Roots_Nav_Walker() by default
 */
function roots_nav_menu_args($args = '')
{
    $roots_nav_menu_args['container'] = false;

    if (!$args['items_wrap']) {
        $roots_nav_menu_args['items_wrap'] = '<ul class="%2$s">%3$s</ul>';
    }

    if (current_theme_supports('bootstrap-top-navbar')) {
        $roots_nav_menu_args['depth'] = 3;
    }

    if (!$args['walker']) {
        $roots_nav_menu_args['walker'] = new Roots_Nav_Walker();
    }

    return array_merge($args, $roots_nav_menu_args);
}

add_filter('wp_nav_menu_args', 'roots_nav_menu_args');