register View-Helper understanding issue - zend-framework

Question

I tried to register a View Helper for navigation, it is an example from olegkrivtsov,I chose this to learn more about the topic. I also read the posts about it. I thought it must be really easy, but it doesn't work, probably some more experienced Zend-developer will see the problem immediately.
First the folder I use, is this the right folder, what is the diffenrence to the folder helpers in the module Import for example?
Here is the content of menu.php
<?php
namespace Application\View\Helper;
use Zend\View\Helper\AbstractHelper;
// This view helper class displays a menu bar.
class Menu extends AbstractHelper
{
// Menu items array.
protected $items = [];
// Active item's ID.
protected $activeItemId = '';
// Constructor.
public function __construct($items=[])
{
$this->items = $items;
}
// Sets menu items.
public function setItems($items)
{
$this->items = $items;
}
// Sets ID of the active items.
public function setActiveItemId($activeItemId)
{
$this->activeItemId = $activeItemId;
}
// Renders the menu.
public function render()
{
if (count($this->items)==0)
return ''; // Do nothing if there are no items.
$result = '<nav class="navbar navbar-default" role="navigation">';
$result .= '<div class="navbar-header">';
$result .= '<button type="button" class="navbar-toggle" ';
$result .= 'data-toggle="collapse" data-target=".navbar-ex1-collapse">';
$result .= '<span class="sr-only">Toggle navigation</span>';
$result .= '<span class="icon-bar"></span>';
$result .= '<span class="icon-bar"></span>';
$result .= '<span class="icon-bar"></span>';
$result .= '</button>';
$result .= '</div>';
$result .= '<div class="collapse navbar-collapse navbar-ex1-collapse">';
$result .= '<ul class="nav navbar-nav">';
// Render items
foreach ($this->items as $item) {
$result .= $this->renderItem($item);
}
$result .= '</ul>';
$result .= '</div>';
$result .= '</nav>';
return $result;
}
// Renders an item.
protected function renderItem($item)
{
$id = isset($item['id']) ? $item['id'] : '';
$isActive = ($id==$this->activeItemId);
$label = isset($item['label']) ? $item['label'] : '';
$result = '';
if(isset($item['dropdown'])) {
$dropdownItems = $item['dropdown'];
$result .= '<li class="dropdown ' . ($isActive?'active':'') . '">';
$result .= '<a href="#" class="dropdown-toggle" data-toggle="dropdown">';
$result .= $label . ' <b class="caret"></b>';
$result .= '</a>';
$result .= '<ul class="dropdown-menu">';
foreach ($dropdownItems as $item) {
$link = isset($item['link']) ? $item['link'] : '#';
$label = isset($item['label']) ? $item['label'] : '';
$result .= '<li>';
$result .= ''.$label.'';
$result .= '</li>';
}
$result .= '</ul>';
$result .= '</a>';
$result .= '</li>';
} else {
$link = isset($item['link']) ? $item['link'] : '#';
$result .= $isActive?'<li class="active">':'<li>';
$result .= ''.$label.'';
$result .= '</li>';
}
return $result;
}
}
I posted the hole example for somebody who also wants to use it.
Here how I tried to register in my module.config.php
'view_helpers' => [
'factories' => [
View\Helper\Menu::class => InvokableFactory::class,
],
'aliases' => [
'mainMenu' => View\Helper\Menu::class
]
],
I placed it in the layout.phtml
<div class="collapse navbar-collapse">
<?php
$this->mainMenu()->setItems([
[
'id' => 'home',
'label' => 'Dashboard',
'link' => $this->url('home')
],
[
'id' => 'project',
'label' => 'Project',
'link' => $this->url("project", ['action'=>'index'])
],
[
'id' => 'unit',
'label' => 'Unit',
'dropdown' => [
[
'id' => 'add',
'label' => 'add Unit',
// 'link' => $this->url('unit', ['page'=>'contents'])
'link' => $this->url('unit', ['action'=>'add'])
],
[
'id' => 'help',
'label' => 'Help',
'link' => $this->url('home')
]
]
],
]);
echo $this->mainMenu()->render();
?>
</div>
With this code I replaced the former part, which came from the skeleton:
<div class="collapse navbar-collapse">
<?= $this->navigation('navigation')
->menu()
->setMinDepth(0)
->setMaxDepth(0)
->setUlClass('nav navbar-nav') ?>
I get this error message via browser:
Fatal error: Uncaught Error: Class 'Application\view\helper\Menu' not found in C:\wamp64\www\xyz\vendor\zendframework\zend-servicemanager\src\Factory\InvokableFactory.php
I'd really love to understand this because it might be really helpful in future, so any suggestion is appreciated.

Answer 1

Move file Menu.php to the folder Application/src/Application/View/Helper