How to Display Vertical mega menu in Magento 2?

Question

I want to display a vertical menu instead of the default horizontal menu for category and subcategory

Answer 1

create a di.xml file in your module etc folder and add the folowing code

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
  <preference for="Magento\Theme\Block\Html\Topmenu" type="Vendor\ModuleName\Block\Topmenu" />
</config>

and create a block file in vendor/modulename/Block/Topmenu.php and override function that is creating the menu by using following code;

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Vendor\ModuleName\Block;


class Topmenu extends \Magento\Theme\Block\Html\Topmenu
{

  protected function _addSubMenu($child, $childLevel, $childrenWrapClass, $limit)
    {
        $html = '';
        if (!$child->hasChildren()) {
            return $html;
        }

        $colStops = [];
        if ($childLevel == 0 && $limit) {
            $colStops = $this->_columnBrake($child->getChildren(), $limit);
        }

        $html .= '<ul class="level' . $childLevel . ' ' . $childrenWrapClass . '">';
        $html .= $this->_getHtml($child, $childrenWrapClass, $limit, $colStops);
        $html .= '</ul>';

        return $html;
    }

 protected function _getHtml(
        \Magento\Framework\Data\Tree\Node $menuTree,
        $childrenWrapClass,
        $limit,
        array $colBrakes = []
    ) {
        $html = '';

        $children = $menuTree->getChildren();
        $parentLevel = $menuTree->getLevel();
        $childLevel = $parentLevel === null ? 0 : $parentLevel + 1;

        $counter = 1;
        $itemPosition = 1;
        $childrenCount = $children->count();

        $parentPositionClass = $menuTree->getPositionClass();
        $itemPositionClassPrefix = $parentPositionClass ? $parentPositionClass . '-' : 'nav-';

        /** @var \Magento\Framework\Data\Tree\Node $child */
        foreach ($children as $child) {
            if ($childLevel === 0 && $child->getData('is_parent_active') === false) {
                continue;
            }
            $child->setLevel($childLevel);
            $child->setIsFirst($counter == 1);
            $child->setIsLast($counter == $childrenCount);
            $child->setPositionClass($itemPositionClassPrefix . $counter);

            $outermostClassCode = '';
            $outermostClass = $menuTree->getOutermostClass();

            if ($childLevel == 0 && $outermostClass) {
                $outermostClassCode = ' class="' . $outermostClass . '" ';
                $currentClass = $child->getClass();

                if (empty($currentClass)) {
                    $child->setClass($outermostClass);
                } else {
                    $child->setClass($currentClass . ' ' . $outermostClass);
                }
            }

            if (is_array($colBrakes) && count($colBrakes) && $colBrakes[$counter]['colbrake']) {
                $html .= '</ul></li><li class="column"><ul>';
            }

            $html .= '<li ' . $this->_getRenderedMenuItemAttributes($child) . '>';
            $html .= '<a href="' . $child->getUrl() . '" ' . $outermostClassCode . '><span>' . $this->escapeHtml(
                $child->getName()
            ) . '</span></a>' . $this->_addSubMenu(
                $child,
                $childLevel,
                $childrenWrapClass,
                $limit
            ) . '</li>';
            $itemPosition++;
            $counter++;
        }

        if (is_array($colBrakes) && count($colBrakes) && $limit) {
            $html = '<li class="column"><ul>' . $html . '</ul></li>';
        }

        return $html;
    }
 protected function _getMenuItemClasses(\Magento\Framework\Data\Tree\Node $item)
    {
        $classes = [];

        $classes[] = 'level' . $item->getLevel();
        $classes[] = $item->getPositionClass();

        if ($item->getIsCategory()) {
            $classes[] = 'category-item';
        }

        if ($item->getIsFirst()) {
            $classes[] = 'first';
        }

        if ($item->getIsActive()) {
            $classes[] = 'active';
        } elseif ($item->getHasActive()) {
            $classes[] = 'has-active';
        }

        if ($item->getIsLast()) {
            $classes[] = 'last';
        }

        if ($item->getClass()) {
            $classes[] = $item->getClass();
        }

        if ($item->hasChildren()) {
            $classes[] = 'parent';
        }

        return $classes;
    }


}

Use your vendor and module name

Answer 2

I have the same question. Can you please help me?

Best: Top navigation only CMS Pages and Main Category and vertical menu all categories with all subcategories.

OK: Same Menu, that I tweak only with CSS that it looks like in {Best}.

I have a own Template (copy of Luma) but I cant find in Magento_Theme/ a folder templates, only layout and web. Where are the files? In blank theme there are also missing.