inanzzz | Preventing 'Confirm form resubmission' dialog in symfony applications

In web application most of us have seen "Confirm Form Resubmission” dialog in pages where there is a form. I believe it annoys most of us like myself. In symfony applications you can use example below to prevent it from happening.

If the form fails, form data is stored in a session and used in form when creating it again. As simple as this. I'll keep it short but I believe you'll see how the session is used here.

Form

namespace My\TestBundle\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;

class InterestType extends AbstractType
{
    const NAME = 'interest';
    
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('name', 'text', ['required' => true]);
        $builder->add('surname', 'text', ['required' => true]);
    }
    
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(['data_class' => 'My\TestBundle\Interest']);
    }

    public function getName()
    {
        return self::NAME;
    }
}

Model

namespace My\TestBundle\Model;

use Symfony\Component\Validator\Constraints as Assert;
use JMS\Serializer\Annotation as Serializer;

class Interest
{
    /**
     * @var string
     *
     * @Assert\NotBlank(message = "Please enter a name.")
     * @Serializer\Type("string")
     */
    public $name;
    
    /**
     * @var string
     *
     * @Assert\NotBlank(message = "Please enter a surname.")
     * @Serializer\Type("string")
     */
    public $surname;
}

Controller

namespace My\TestBundle\Controller;

use My\TestBundle\Type\InterestType;
use My\TestBundle\Model\Interest;
use Symfony\Component\Form\FormFactoryInterface;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\RouterInterface;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Template;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Method;

/**
 * @Route("/interest", service="my_test_bundle.controller.interest")
 */
class InterestController
{
    private $formFactory;
    private $router;

    public function __construct(
        FormFactoryInterface $formFactory,
        RouterInterface $router
    ) {
        $this->formFactory = $formFactory;
        $this->router = $router;
    }

    /**
     * @Method({"GET"})
     * @Route("", name="interest_index")
     * @Template()
     *
     * @param Request $request
     *
     * @return array
     */
    public function indexAction(Request $request)
    {
        $form = $this->createForm();

        $session = $request->getSession();
        if ($session->has($this->getFormName())) {
            $request->request->set(
                $this->getFormName(),
                unserialize($session->get($this->getFormName()))
            );
            $request->setMethod('POST');
            $form->handleRequest($request);
        }

        return ['interest_form' => $form->createView()];
    }

    /**
     * @Method({"POST"})
     * @Route("", name="interest_create")
     *
     * @param Request $request
     *
     * @return RedirectResponse
     */
    public function createAction(Request $request)
    {
        $session = $request->getSession();

        $form = $this->createForm();
        $form->handleRequest($request);
        if ($form->isValid()) {
            // Do something with: $form->getData();

            $session->remove($this->getFormName());
            $routeName = 'home_or_success_route';
        } else {
            $session->set(
                $this->getFormName(),
                serialize($request->request->get($this->getFormName()))
            );

            $routeName = 'interest_index';
        }

        return new RedirectResponse($this->router->generate($routeName));
    }

    private function createForm()
    {
        return $this->formFactory->create(
            InterestType::class,
            new Interest(),
            [
                'method' => 'POST',
                'action' => $this->router->generate('interest_create'),
                'attr' => ['id' => $this->getFormName()],
            ]
        );
    }

    private function getFormName()
    {
        return InterestType::NAME;
    }
}