And... action!

Our journey through the blog example is not only an educational, but also an activity holiday. We now turn to the activities. We are already in the BlogController. You can find the class file under EXT:blog_example/Classes/BlogController.php.

In software development, there are different variants of controllers. In Extbase the controllers mostly exist as ActionController. This variant is characterized by short methods, which are responsible for the control of a single action, the so called Actions. Let's have a deeper look at a shortened version of the BlogController:

Classes/BlogController.php

 <?php

 namespace MyVendor\BlogExample\Controller;

 class BlogController
       extends \TYPO3\CMS\Extbase\Mvc\Controller\ActionController {

     public function indexAction() {
         $this->view->assign('blogs', $this->blogRepository->findAll());
     }

     public function newAction(\MyVendor\BlogExample\Domain\Model\Blog $newBlog = null) {
         $this->view->assign('newBlog', $newBlog);
         $this->view->assign('administrators', $this->administratorRepository->findAll());
     }

     public function createAction(\MyVendor\BlogExample\Domain\Model\Blog $newBlog) {
         $this->blogRepository->add($newBlog);
         $this->redirect('index');
     }

     public function editAction(\MyVendor\BlogExample\Domain\Model\Blog $blog) {
         $this->view->assign('blog', $blog);
         $this->view->assign('administrators', $this->administratorRepository->findAll());
     }

     public function updateAction(\MyVendor\BlogExample\Domain\Model\Blog $blog) {
         $this->blogRepository->update($blog);
         // this does currently not work, use $this->blogRepository->add($blog); instead
         // see issue: https://forge.typo3.org/issues/76876
         $this->redirect('index');
     }

     public function deleteAction(\MyVendor\BlogExample\Domain\Model\Blog $blog) {
         $this->blogRepository->remove($blog);
         $this->redirect('index');
     }

 }

The method indexAction() within the BlogController is responsible for showing a list of blogs. We also could have called it showMeTheListAction(). The only important point is, that it ends with Action in order to help Extbase to recognize it as an action. newAction() shows a form to create a new blog. The createAction() then creates a new blog with the data of the form. The pair editAction() and updateAction() have a similar functionality for the change of an existing blog. The job of the deleteAction() should be self explaining.

Tip

Who already dealed with the model-view-controller-pattern will notice, that the controller has only a little amount of code. Extbase (and FLOW3) aim to the approach to have a slim controller. The controller is exclusively responsible for the control of the process flow. Additional logic (especially business or domain logic) needs to be seperated into classes in the subfolder Domain.

Tip

The name of the action is strictly spoken only the part without the suffix Action, e.g. list, show or edit. With the suffix Action the name of the action-method is marked. But we use the action itself and its method mostly synonymous.

From the request the controller can extract which action has to be called. The call is happening without the need to write another line of code in the BlogController. This does \TYPO3\CMS\Extbase\Mvc\Controller\ActionController. The BlogController "inherits" all methods from it, by deriving it form this class:

<?php
namespace MyVendor\BlogExample\Controller;

class BlogController extends
    \TYPO3\CMS\Extbase\Mvc\Controller\ActionController {...}

At first call of the plugin without additional information the request will get a standard action; in our case the indexAction(). The indexAction() contains only one line in our example (as shown above), which looks more detailled like this:

public function indexAction() {
    $blogRepository = GeneralUtility::makeInstance('\MyVendor\BlogExample\Domain\Repository\BlogRepository');
    $allAvailableBlogs = $blogRepository->findAll();
    $this->view->assign('blogs', $allAvailableBlogs);
    $content = $this->view->render();
    return $content;
}

In the first line a repository is instantiated, which "contains" all blogs. How they are saved and managed, is not of interest at this point of our journey. All files, which are defined in the repository-classes, are located in the folder EXT:blog_example/Classes/Domain/Repository/. This you can also derive directly from the Name BlogExample_Domain_Repository_BlogRepository. This naming scheme is a big advantage by the way, if you search a particular class file. The name BlogRepository results from the name of the class, whose instances are managed by the repository, namely by adding Repository. A repository can only manage one single class at a time. The second line retrieves all available blogs by findAll().