wp-bootstrap4-navwalker-Mega

A custom WordPress nav walker class to fully implement the Bootstrap 4.0+ navigation style with Mega Menu items in a custom theme using the WordPress built in menu manager.

http://prntscr.com/h7206f <- screenshot of menu

http://prntscr.com/h720sy < - screenshot of widgets screen

http://prntscr.com/h721hh <- screenshot of menu screen

This version adds the support for multi level dropdowns with Mega Menu type nav items

NOTE

This is a utility class that is intended to format your WordPress theme menu with the correct syntax and classes to utilize the Bootstrap dropdown navigation, and does not include the required Bootstrap JS files. You will have to include them manually.

Installation

Place wp_bootstrap4-mega-navwalker.php in your WordPress theme folder /wp-content/your-theme/

Open your WordPress themes functions.php file /wp-content/your-theme/functions.php and add the following code:

	// Register Custom Navigation Walker
	require_once('wp_bootstrap4-mega-navwalker.php');

Usage

Update your wp_nav_menu() function in header.php to use the new walker by adding a "walker" item to the wp_nav_menu array.

 <?php
       $args = array(
		  'theme_location' => 'mega_menu',
		  'depth' => 0,
		  'menu_class'  => 'navbar-nav mr-auto',
		  'walker'  => new BootstrapNavMenuWalker()
          );
    wp_nav_menu($args);
        ?>

Your menu will now be formatted with the correct syntax and classes to implement Bootstrap dropdown navigation.

You will also want to declare your new menu in your functions.php file.

register_nav_menus( array(
'mega_menu'   => __( 'Mega Menu', 'your-theme' ),
) );

Now you will need to add the Widget that will contain the mega-menu item's HTML. In your functions file add this code to the register sidebars function:

//register MegaMenu widget if the Mega Menu is set as the menu location
$location = 'mega_menu';
$css_class = 'mega-menu-parent';
$locations = get_nav_menu_locations();
if ( isset( $locations[ $location ] ) ) {
  $menu = get_term( $locations[ $location ], 'nav_menu' );
  if ( $items = wp_get_nav_menu_items( $menu->name ) ) {
    foreach ( $items as $item ) {
      if ( in_array( $css_class, $item->classes ) ) {
        register_sidebar( array(
          'id'   => 'mega-menu-item-' . $item->ID,
          'description' => 'Mega Menu items',
          'name' => $item->title . ' - Mega Menu',
          'before_widget' => '<li id="%1$s" class="mega-menu-item">',
          'after_widget' => '</li>', 

        ));
      }
    }
  }
}

Typically the menu is wrapped with additional markup, here is an example of a navbar-fixed-top menu that collapse for responsive navigation.

<nav class="navbar navbar-expand-md navbar-dark bg-dark fixed-top">
  <div class="container">
    <!-- custom calls to options stored in Admin section "Theme Options" to display the logo or not -->
     <a class="navbar-brand" id="logo" href="<?php echo site_url(); ?>"><img src="<?php header_image(); ?>" alt="Our Logo" class="img-responsive logo"/></a>
    <!-- custom calls to options stored in Admin section "Theme Options" to display the logo or not -->
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#bootstrap-nav-collapse" aria-controls="jd-bootstrap-nav-collapse" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>

    <!-- Collect the nav links from WordPress -->
    <div class="collapse navbar-collapse" id="bootstrap-nav-collapse">         
		  <?php 

      $args = array(
        'theme_location' => 'mega_menu', // primary_menu or mega-menu
        'depth' => 0,
        'container' => '',
        'menu_class'  => 'navbar-nav mr-auto',
        'walker'  => new BootstrapNavMenuWalker()
        );
      wp_nav_menu($args);
      ?>
    </div><!-- ./collapse -->
  </div><!-- /.container -->
</nav>

Displaying the Menu

To display the menu you must associate your menu with your theme location. You can do this by selecting your theme location in the Theme Locations list wile editing a menu in the WordPress menu manager and selecting mega-menu.

Displaying the Mega Menu

To display the mega menu items add the class "mega-menu-parent" to the menu item in the WordPress menu manager. This will create a new widget in the widgets section with the same name as the nav parent. Add a Custom HTML widget and code your mega menu items using default bootstrap containers, rows and cols. Add a search widget or any other widget, style the CSS by the item's ID.

Additional CSS to get the menu to display correctly:

/**Mega Menu **/
.navbar .container {
    position: relative;
}
.navbar-nav, .navbar .collapse, .navbar-nav li {
  position: static;
}
.menu-item-has-children, .menu-item-has-children .dropdown-menu {
  left: auto;
}
.menu-item-has-children .dropdown-menu {
  width: auto !important;
}

And optional css for a hover/fade inUp effect

/* Make dropdown visible on hover */
@media (min-width: 767px) {
  .dropdown > .dropdown-menu {
    position: absolute;
    top: 100%;
    left: auto;
    z-index: 1000;
    float: none;
    min-width: 10rem;
    padding: 1rem;
    list-style: none;
    border: none;
    border-radius: 0;
    box-shadow: none;
    opacity: 0;
    margin-top: 10px !important;
    display: block;
    visibility:hidden;
    min-width: 150px;
    transition: all  0.2s ease-in-out;
  }
  .dropdown:hover > .dropdown-menu {
    visibility:visible;
    display: block;
    opacity: 1;
    margin-top: 5px !important; 
    border-bottom-right-radius: 8px;
    border-bottom-left-radius: 8px;
    transition: all  0.2s ease-in-out;
  }
    .mega-menu-parent.dropdown .dropdown-menu {
    position: absolute;
    left:  0;
  }
}

jQuery for hover:

$('body').on('mouseenter mouseleave', '.dropdown', function (e) {
    var dropdown = $(e.target).closest('.dropdown');
    var menu = $('.dropdown-menu', dropdown);
    dropdown.addClass('show');
    menu.addClass('show');
    setTimeout(function () {
        dropdown[dropdown.is(':hover') ? 'addClass' : 'removeClass']('show');
        menu[dropdown.is(':hover') ? 'addClass' : 'removeClass']('show');
    }, 300);
});