Multilevel drop-down menu in WordPress with Bootstrap 3

To integrate Bootstrap 3 navigation menu to WordPress you can use the following walker class:

https://github.com/twittem/wp-bootstrap-navwalker

But, the problem is it only allows a single dropdown level to honer BootStrap 3's mobile first philosophy. Fortunately, the guy this blog post had done a little hack to bootstrap and the walker class above to support multilevel drop-down menu:

Blog post: http://www.jeffmould.com/2014/01/09/responsive-multi-level-bootstrap-menu/

Github repo: https://github.com/jeffmould/multi-level-bootstrap-menu


Basically, what you should do to have a bootstrap 3 style dropdown menu in your WordPress theme are:

1. Copy the wp-bootstrap-navwalker.php file from the github repo to the theme's root directory

2. Add this style to your theme:

.dropdown-submenu{position:relative;}
.dropdown-submenu>.dropdown-menu{top:0;left:100%;-webkit-border-radius:0 6px 6px 6px;-moz-border-radius:0 6px 6px 6px;border-radius:0 6px 6px 6px;}
.dropdown-submenu:active>.dropdown-menu, .dropdown-submenu:hover>.dropdown-menu {
       display: block;
       right:162px;
}
.dropdown-submenu>a:after{display:block;content:" ";float:right;width:0;height:0;border-color:transparent;border-style:solid;border-width:5px 0 5px 5px;border-left-color:#cccccc;margin-top:5px;margin-right:-10px;}
.dropdown-submenu:active>a:after{border-left-color:#ffffff;}
.dropdown-submenu.pull-left{float:none;}.dropdown-submenu.pull-left>.dropdown-menu{left:-100%;margin-left:10px;-webkit-border-radius:6px 0 6px 6px;-moz-border-radius:6px 0 6px 6px;border-radius:6px 0 6px 6px;}

(the red line is my modification to move the submenu pan to the left a little bit)

3. Use the bootstrap.js file from the above github repo instead.

4. Add these lines to functions.php to register the menu:

# Menu
require_once('wp_bootstrap_navwalker.php');
function register_my_menu() {
register_nav_menu('my-menu',__( 'My Menu' ));
}
add_action( 'init', 'register_my_menu' );

5. Display the menu in your theme:

<?php 
$menu_args = array(
'menu' => 'my-menu',
'theme_location' => 'my-menu',
'depth' => 4,
'container' => false,
'menu_class' => 'nav navbar-nav navbar-right',
'fallback_cb'       => 'wp_bootstrap_navwalker::fallback',
'walker' => new wp_bootstrap_navwalker()
);
wp_nav_menu($menu_args);
?>

This is will add 4 level dropdown menu to your template.


Notes:

1. If the origin github repo is down or deleted for some reasons, you can try my folked repo: https://github.com/dangtrinh/multi-level-bootstrap-menu.

2. Please note that this is against the original design philosophy of Bootstrap which is mobile first which may causes bad UX on the mobile devices.