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 Tx_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 Tx_Inventory_Controller_InventoryController.

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 Tx_Inventory_Controller_ProductController.

In our simple example the controller looks like this:

<?php
class Tx_Inventory_Controller_InventoryController
      extends Tx_Extbase_MVC_Controller_ActionController {

    public function listAction() {
        $productRepository = t3lib_div::makeInstance('Tx_Inventory_Domain_Repository_ProductRepository');
        $products = $productRepository->findAll();
        $this->view->assign('products', $products);
    }
}
?>

Our Tx_Inventory_Controller_InventoryController must be derived from the Tx_Extbase_MVC_Controller_ActionController. It contains only the method findAll(). Extbase identifies all methods that ends with Action as actions - so as little plan of procedures.

In the first line of the listAction() the ProductRepository is instanced. The products to be shown we get by the method findAll() of the repository. This method is implemented in the class Tx_Extbase_Persistence_Repository. Which methods are also still for disposition you can read in chapter 6.

Tip

Take care about using the framework method t3lib_div::makeInstance() of TYPO3 instead of the keyword new to create new instances of the repository. Background for familiar folks: The repository is a so called Singleton and is marked accordingly for that. The method makeInstance() recognize the singleton by means of the identification mark and returns - after the first creation - always the same object, independent of the place in your code where it is requested. In contrast the creation with “new” always returns a new and therefor empty repository object.

As result we get a PHP array 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.