code: public function UpdateAction()
    {
      // Gets the article id, then stores it
      $id = $_GET['id'];
  
      // Checks if the form has been completed
      if (!empty($_POST))
      {
        // Checks if a new file has been uploaded
        if (!empty($_FILES['file']['name']))
        {
          // Uploads the image, then gets back the file name
          $data['image'] = $this->upload('img/blog');
        }
        // Retrieves form data & stores them
        $data['title']        = $_POST['title'];
        $data['link']         = $_POST['link'];
        $data['content']      = $_POST['content'];
        $data['updated_date'] = $_POST['date'];
  
        // Updates the article
        ModelFactory::get('Article')->update($id, $data);
  
        // Creates an info message to confirm the update of the selected article
        htmlspecialchars(Session::createAlert('Successful modification of the selected article !', 'info'));
  
        // Redirects to the admin
        $this->redirect('admin');
      }
      // Reads the article, then store it
      $article = ModelFactory::get('Article')->read($id);
  
      // Returns the rendering of the view updateArticle with the current article
      return $this->render('admin/blog/updateArticle.twig', ['article' => $article]);
    }
docs: ****************\
  Updates an article
  @return mixed => the rendering of the view updateArticle