Override Topmenu Block in Magento 2 - php

Question

I am trying to override the Topmenu block in Magento 2 so that I can change the HTML structure of my sub menus but I can't seem to get past this problem.
What I have done
I have created a module called Ecommerce\Topmenu.
Files
app/code/Ecommerce/Topmenu
-- etc/
--- di.xml
--- module.xml
-- Plugin/
--- Topmenu.php
-- registration.php
Topmenu.php
<?php
/**
* Copyright © 2013-2017 Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
namespace Ecommerce\Topmenu\Plugin;
use \Magento\Framework\DataObject\IdentityInterface;
use \Magento\Framework\View\Element\Template;
use \Magento\Framework\Data\TreeFactory;
use \Magento\Framework\Data\Tree\Node;
use \Magento\Framework\Data\Tree\NodeFactory;
/**
* Html page top menu block
*/
class Topmenu extends \Magento\Theme\Block\Html\Topmenu
{
/**
* Get top menu html
*
* #param string $outermostClass
* #param string $childrenWrapClass
* #param int $limit
* #return string
*/
public function getHtml($outermostClass = '', $childrenWrapClass = '', $limit = 0)
{
$this->_eventManager->dispatch(
'page_block_html_topmenu_gethtml_before',
['menu' => $this->_menu, 'block' => $this]
);
$this->_menu->setOutermostClass($outermostClass);
$this->_menu->setChildrenWrapClass($childrenWrapClass);
$html = $this->_getHtml($this->_menu, $childrenWrapClass, $limit);
$transportObject = new \Magento\Framework\DataObject(['html' => $html]);
$this->_eventManager->dispatch(
'page_block_html_topmenu_gethtml_after',
['menu' => $this->_menu, 'transportObject' => $transportObject]
);
$html = $transportObject->getHtml();
return $html;
}
/**
* Count All Subnavigation Items
*
* #param \Magento\Backend\Model\Menu $items
* #return int
*/
protected function _countItems($items)
{
$total = $items->count();
foreach ($items as $item) {
/** #var $item \Magento\Backend\Model\Menu\Item */
if ($item->hasChildren()) {
$total += $this->_countItems($item->getChildren());
}
}
return $total;
}
/**
* Building Array with Column Brake Stops
*
* #param \Magento\Backend\Model\Menu $items
* #param int $limit
* #return array|void
*
* #todo: Add Depth Level limit, and better logic for columns
*/
protected function _columnBrake($items, $limit)
{
$total = $this->_countItems($items);
if ($total <= $limit) {
return;
}
$result[] = ['total' => $total, 'max' => (int)ceil($total / ceil($total / $limit))];
$count = 0;
$firstCol = true;
foreach ($items as $item) {
$place = $this->_countItems($item->getChildren()) + 1;
$count += $place;
if ($place >= $limit) {
$colbrake = !$firstCol;
$count = 0;
} elseif ($count >= $limit) {
$colbrake = !$firstCol;
$count = $place;
} else {
$colbrake = false;
}
$result[] = ['place' => $place, 'colbrake' => $colbrake];
$firstCol = false;
}
return $result;
}
/**
* Add sub menu HTML code for current menu item
*
* #param \Magento\Framework\Data\Tree\Node $child
* #param string $childLevel
* #param string $childrenWrapClass
* #param int $limit
* #return string HTML code
*/
protected function _addSubMenu($child, $childLevel, $childrenWrapClass, $limit)
{
$html = '';
if (!$child->hasChildren()) {
return $html;
}
$colStops = null;
if ($childLevel == 0 && $limit) {
$colStops = $this->_columnBrake($child->getChildren(), $limit);
}
$html .= '<ul class="level' . $childLevel . ' megaSub">';
$html .= $this->_getHtml($child, $childrenWrapClass, $limit, $colStops);
$html .= '</ul>';
return $html;
}
/**
* Recursively generates top menu html from data that is specified in $menuTree
*
* #param \Magento\Framework\Data\Tree\Node $menuTree
* #param string $childrenWrapClass
* #param int $limit
* #param array $colBrakes
* #return string
*
* #SuppressWarnings(PHPMD.CyclomaticComplexity)
* #SuppressWarnings(PHPMD.NPathComplexity)
*/
protected function _getHtml(
\Magento\Framework\Data\Tree\Node $menuTree,
$childrenWrapClass,
$limit,
$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 ? $parentPositionClass . '-' : 'nav-';
foreach ($children as $child) {
$child->setLevel($childLevel);
$child->setIsFirst($counter == 1);
$child->setIsLast($counter == $childrenCount);
$child->setPositionClass($itemPositionClassPrefix . $counter);
$outermostClassCode = '';
$outermostClass = $menuTree->getOutermostClass();
if ($childLevel == 0 && $outermostClass) {
$outermostClassCode = ' class="' . $outermostClass . '" ';
$child->setClass($outermostClass);
}
if (count($colBrakes) && $colBrakes[$counter]['colbrake']) {
// $html .= '</ul></li><li class="column"><ul>';
}
if($counter > 1 && $childLevel == 1){
continue;
}
$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++;
$counter++;
}
if (count($colBrakes) && $limit) {
$html = '<li class="column"><ul>' . $html . '</ul></li>';
}
return $html;
}
/**
* Generates string with all attributes that should be present in menu item element
*
* #param \Magento\Framework\Data\Tree\Node $item
* #return string
*/
protected function _getRenderedMenuItemAttributes(\Magento\Framework\Data\Tree\Node $item)
{
$html = '';
$attributes = $this->_getMenuItemAttributes($item);
foreach ($attributes as $attributeName => $attributeValue) {
$html .= ' ' . $attributeName . '="' . str_replace('"', '\"', $attributeValue) . '"';
}
return $html;
}
/**
* Returns array of menu item's attributes
*
* #param \Magento\Framework\Data\Tree\Node $item
* #return array
*/
protected function _getMenuItemAttributes(\Magento\Framework\Data\Tree\Node $item)
{
$menuItemClasses = $this->_getMenuItemClasses($item);
return ['class' => implode(' ', $menuItemClasses)];
}
/**
* Returns array of menu item's classes
*
* #param \Magento\Framework\Data\Tree\Node $item
* #return array
*/
protected function _getMenuItemClasses(\Magento\Framework\Data\Tree\Node $item)
{
$classes = [];
$classes[] = 'level' . $item->getLevel();
$classes[] = $item->getPositionClass();
if ($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;
}
/**
* Add identity
*
* #param array $identity
* #return void
*/
public function addIdentity($identity)
{
if (!in_array($identity, $this->identities)) {
$this->identities[] = $identity;
}
}
/**
* Get identities
*
* #return array
*/
public function getIdentities()
{
return $this->identities;
}
/**
* Get cache key informative items
*
* #return array
*/
public function getCacheKeyInfo()
{
$keyInfo = parent::getCacheKeyInfo();
$keyInfo[] = $this->getUrl('*/*/*', ['_current' => true, '_query' => '']);
return $keyInfo;
}
/**
* Get tags array for saving cache
*
* #return array
*/
protected function getCacheTags()
{
return array_merge(parent::getCacheTags(), $this->getIdentities());
}
/**
* Get menu object.
*
* #return Node
*/
public function getMenu()
{
return $this->_menu;
}
}
** Expected behavour **
My module should override the Magento Topmenu module whilst inheriting it allowing me to change the output markup
The problem
After running setup:upgrade and recompiling, I am just presented with the following error:
Fatal error: Call to a member function setOutermostClass() on null in /var/www/myecom.co.uk/app/code/Ecommerce/Topmenu/Plugin/Topmenu.php on line 36
It's like my code is not correctly extending the Topmenu block.
Any ideas?

Answer 1

For fix this my solution is insert construct as below:
public function __construct(Template\Context $context, NodeFactory $nodeFactory, TreeFactory $treeFactory, array $data = [])
{
parent::__construct($context, $nodeFactory, $treeFactory, $data);
$this->nodeFactory = $nodeFactory;
$this->treeFactory = $treeFactory;
}

Answer 2

This problem is a result of a recent Magento update which explains why I was having this problem using code that had previously worked for me on earlier Magento versions.
Final Solution
The final solution to fix this after Magento's update is to replace $this->_menu with $this->getMenu()
Now the working version of my custom module extends the Magento top menu class and just overrides the _getHtml function to change the markup as required.