Widget_Controller.php

<?php
  class Widget_Controller extends Dev_Controller {

    public function show() {
      $params = $this->app->request()->params();
      // Here we use a "null object" that initialises all attributes to empty strings or other sensible defaults
      $this->render(new Widget());
    }
    
    public function create() {
      $params = $this->app->request()->params();
      $widget = new Widget($params);
      
      if (widget->save()) {
        $this->app->redirect('/somewhere_else');
      } else {
        // Here we pass the invalid, unsaved object back to the template so that it can be re-rendered along with its errors
        $this->render($widget);
      }
    }

    private function render($widget) {
      $this->app->render('widget.twig', array(
        'data' => $widget,
        'errors' => $widget->getErrors()
      ));
    }
  }
?>