Controlling The Flow

The inventory created in the backend should be shown as a list in the frontend now. The creation of the HTML code out of the product objects to be shown is done by the view. Extbase uses the class \TYPO3\CMS\Fluid\View\TemplateView of the extension Fluid as default for the view.

The connection between the model and the view is the controller. It controls the sequences inside the extension and is responsible for the list action in our case. This includes locating the products which are to be shown, as well as transmission of the selected products to the responsible view.

The class name of the controller must end with Controller. Because our controller controls the display of the inventory we call it \MyVendor\StoreInventory\Controller\StoreInventoryController.

Tip

When naming a controller you are free inside the described frame. We advise to name a controller by what he "controls". In big projects these are specially the aggregate root objects (see section "aggregates" in chapter 2). For this we had also named our controller MyVendor\StoreInventory\Controller\ProductController.

In our simple example the controller looks like this:

<?php

namespace MyVendor\StoreInventory\Controller;

use MyVendor\StoreInventory\Domain\Repository\ProductRepository;
use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;

/**
 * Class StoreInventoryController
 *
 * @package MyVendor\StoreInventory\Controller
 */
class StoreInventoryController extends ActionController
{

    /**
     * @var ProductRepository
     */
    private $productRepository;

    /**
     * Inject the product repository
     *
     * @param \MyVendor\StoreInventory\Domain\Repository\ProductRepository $productRepository
     */
    public function injectProductRepository(ProductRepository $productRepository)
    {
        $this->productRepository = $productRepository;
    }

    /**
     * List Action
     *
     * @return void
     */
    public function listAction()
    {
        $products = $this->productRepository->findAll();
        $this->view->assign('products', $products);
    }
}

Our \MyVendor\StoreInventory\Controller\StoreInventoryController must be derived from the \TYPO3\CMS\Extbase\Mvc\Controller\ActionController. It contains only the method listAction(). Extbase identifies all methods that ends with Action as actions - so as little plan of procedures.

In the method injectProductRepository() the ProductRepository is instanced. Now we can access the repository with $this->productRepository in all actions. It is important to get the repository with the injector method, because the repository implements the SingletonInterface and therefore we are not allowed to use the new keyword to get a instance of the repository. There must always be only one repository in memory!

In the listAction we get all products by the method findAll() of the repository. This method is implemented in the class \TYPO3\CMS\Extbase\Persistence\Repository. Which methods are also still for disposition you can read in chapter 6.

As result we get a \TYPO3\CMS\Extbase\Persistence\Generic\QueryResult object with the product objects. We pass these objects to the view with $this->view->assign(…). Without our further assistance, at the end of the action the view is invited to return the passed content rendered based on a HTML template back to TYPO3.

return $this->view->render();

This line is declined by Extbase for us, if we not initiate the rendering process ourselves. So we can omit the line in our case.