Zend2 navigation global to layout - php

Question

I have a CategoryController with a fetchSingle (return 1 record) and fetchAll (returns all) method from dbase.
Now i want to reuse de fetchall method for a Navigation.
What's the best approach?
Following code:
Module.php
public function getServiceConfig()
{
return array(
'factories' => array(
/*
* Category Table
*/
'CategoryTableGateway' => function ($sm) {
$dbAdapter = $sm->get('Zend\Db\Adapter\Adapter');
$resultSetPrototype = new ResultSet();
return new TableGateway('category', $dbAdapter, null, $resultSetPrototype);
},
'CategoryTable' => function($sm) {
$tableGateway = $sm->get('CategoryTableGateway');
$table = new Model\CategoryTable($tableGateway);
return $table;
},
),
);
}
CategoryController:
namespace Front\Controller;
use Zend\Mvc\Controller\AbstractActionController;
use Zend\View\Model\ViewModel;
class CategoryController extends AbstractActionController
{
protected $categoryTable;
function indexAction() {
//$slug = $this->getEvent()->getRouteMatch()->getParam('slug');
$this->layout()->setVariable('metatitle', 'title1');
$this->layout()->setVariable('metadescription', 'description2');
$this->layout()->setVariable('metakeywords', 'keywords3');
return new ViewModel(array(
'category' => $this->getCategories(),
));
}
public function getCategory( $slug ){
return $this->getTable()->getCategory($slug);
}
public function getCategories(){
return $this->getTable()->getCategories();
}
public function getTable()
{
if (!$this->categoryTable) {
$sm = $this->getServiceLocator();
$this->categoryTable = $sm->get('CategoryTable');
}
return $this->categoryTable;
}
}
CategoryModel:
namespace Front\Model;
use Zend\Db\TableGateway\TableGateway;
class CategoryTable {
protected $tableGateway;
public function __construct(TableGateway $tableGateway)
{
$this->tableGateway = $tableGateway;
}
public function getCategory($slug)
{
$resultSet = $this->tableGateway->select(array('name' => $slug));
$resultSet = $resultSet->toArray();
return $resultSet[0];
}
public function getCategories()
{
$resultSet = $this->tableGateway->select();
$resultSet = $resultSet->toArray();
return $resultSet;
}
}

Answer 1

If you want to have a navigation element on your side, you can start with a custom view heler. The helper will load the categories and construct a navigation menu.
A view helper can look like this:
namespace MyApp\View\Helper;
use MyApp\Repository\CategoryRepository;
use Zend\Navigation\Navigation;
use Zend\View\Helper\AbstractHelper;
class CategoryMenu
{
protected $repository;
public function __construct(CategoryRepository $repository)
{
$this->repository = $repository
}
public function __invoke(array $options = array)
{
$categories = $this->repository->fetchAll();
$container = $this->buildNavigation($categories);
$navigation = $this->getView()->navigation();
return $navigation->menu()->renderMenu($container, $options);
}
private function buildNavigation(array $categories)
{
$pages = [];
foreach ($categories as $category) {
$pages[] = [
'label' => $category->getName(),
'route' => 'categories/view',
'params' => ['id' => $category->getId()]
];
}
return new Navigation($pages);
}
}
This helper requires a repository (do not use fetchSingle() or fetchAll() in controllers, they are mapper / repository methods!). When you invoke the helper, it fetches all categories from the database, builds a navigation object and calls the navigation view helper to render it into a menu.
I am not writing all glueing parts down, but you require a decent repository so you can access the database and a factory for this view helper. Then register the view helper in your module configuration.
The $options from __invoke() are passed onto the menu helper, so you can apply options there (like, the ulClass, min/max depth etc). Usage: <div><?= $this->categoryMenu([])?></div>.
Note I tried to link all categories to a page, but I was missing that information from your question. I assume here the route categories/view exists and it requires a parameter id for the category id. Update the buildNavigation() method to suit it your own needs.

Answer 2

If you aiming the best approach, your controllers shouldn't fetch anything from database. This is a service (better) data layer (best) job. You need to consume that service in controller while consuming fetch/fetchAll methods of the repository (data layer) in service.
When you move that fetch and fetchAll logic into dedicated classes as dedicated methods, you'll easily figure out how to reuse them and question becomes "How can i inject my x service to my CategoryController?".
I suggest you focus on reading few articles on topics like separating of concerns.