add symfony forms

ShowAction.php

<?php

namespace App\Http\Action\Blog;

use App\ReadModel\PostReadRepository;
use Framework\Template\TemplateRenderer;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\RequestHandlerInterface;
use Zend\Diactoros\Response\EmptyResponse;
use Zend\Diactoros\Response\HtmlResponse;
use Symfony\Component\Validator\Constraints\Length;
use Symfony\Component\Validator\Constraints\NotBlank;

use Symfony\Component\Validator\Validation;
use Symfony\Bridge\Twig\Form\TwigRendererEngine;
use Symfony\Component\Form\Forms;
use Symfony\Component\Form\Extension\Validator\ValidatorExtension;
use Symfony\Component\Form\Extension\Csrf\CsrfExtension;
use Symfony\Component\Security\Csrf\CsrfTokenManager;
use Symfony\Component\Translation\Translator;
use Symfony\Component\Translation\Loader\XliffFileLoader;
use Symfony\Bridge\Twig\Extension\TranslationExtension;
use Symfony\Bridge\Twig\Extension\FormExtension;
use Symfony\Bridge\Twig\Form\TwigRenderer;

class ShowAction implements RequestHandlerInterface
{
    private $posts;
    private $template;

    public function __construct(PostReadRepository $posts, TemplateRenderer $template)
    {
        $this->posts = $posts;
        $this->template = $template;
    }

    public function handle(ServerRequestInterface $request): ResponseInterface
    {
        if (!$post = $this->posts->find($request->getAttribute('id'))) {
            return new EmptyResponse(404);
        }

        // Set up the Validator component
        $validator = Validation::createValidator();
        // Set up the Form component
        $formFactory = Forms::createFormFactoryBuilder()
            ->addExtension(new ValidatorExtension($validator))
            ->getFormFactory();

        // Create our first form!
        $form = $formFactory->createBuilder()
            ->add('firstName', 'text', array(
                'constraints' => array(
                    new NotBlank(),
                    new Length(array('min' => 4)),
                ),
            ))
            ->add('lastName', 'text', array(
                'constraints' => array(
                    new NotBlank(),
                    new Length(array('min' => 4)),
                ),
            ))
            ->add('gender', 'choice', array(
                'choices' => array('m' => 'Male', 'f' => 'Female'),
            ))
            ->add('newsletter', 'checkbox', array(
                'required' => false,
            ))
            ->getForm();

        if (isset($_POST[$form->getName()])) {
            $form->submit($_POST[$form->getName()]);
            if ($form->isValid()) {
                var_dump('VALID', $form->getData());
                die;
            }
        }

        return new HtmlResponse($this->template->render('app/blog/show', [
            'post' => $post,
            'form' => $form->createView(),
        ]));
    }
}

TwigEnvironmentFactory.php

<?php

namespace Infrastructure\Framework\Template\Twig;

use Framework\Template\Twig\Extension\RouteExtension;
use Psr\Container\ContainerInterface;
use Twig\Environment;
use Twig\Extension\DebugExtension;
use Twig\Loader\FilesystemLoader;

use Symfony\Component\Validator\Validation;
use Symfony\Bridge\Twig\Form\TwigRendererEngine;
use Symfony\Component\Form\Forms;
use Symfony\Component\Form\Extension\Validator\ValidatorExtension;
use Symfony\Component\Form\Extension\Csrf\CsrfExtension;
use Symfony\Component\Security\Csrf\CsrfTokenManager;
use Symfony\Component\Translation\Translator;
use Symfony\Component\Translation\Loader\XliffFileLoader;
use Symfony\Bridge\Twig\Extension\TranslationExtension;
use Symfony\Bridge\Twig\Extension\FormExtension;
use Symfony\Bridge\Twig\Form\TwigRenderer;

define('DEFAULT_FORM_THEME', 'form_div_layout.html.twig');

//define('VENDOR_DIR', realpath(__DIR__ . '/../vendor'));
define('VENDOR_DIR', '/home/kotov/PhpstormProjects/php-demo-psr7-framework/vendor');


define('VENDOR_FORM_DIR', VENDOR_DIR . '/symfony/form');
define('VENDOR_VALIDATOR_DIR', VENDOR_DIR . '/symfony/validator');
define('VENDOR_TWIG_BRIDGE_DIR', VENDOR_DIR . '/symfony/twig-bridge');
define('VIEWS_DIR', realpath(__DIR__ . '/../views'));

$reflection = new \ReflectionClass(\Composer\Autoload\ClassLoader::class);
$vendorDir = dirname(dirname($reflection->getFileName()));

class TwigEnvironmentFactory
{

    public function __invoke(ContainerInterface $container)
    {
        $debug = $container->get('config')['debug'];
        $config = $container->get('config')['twig'];

        $loader = new FilesystemLoader();
        $loader->addPath($config['template_dir']);
        $loader->addPath(VENDOR_TWIG_BRIDGE_DIR . '/Resources/views/Form');

        $environment = new Environment($loader, [
            'cache' => $debug ? false : $config['cache_dir'],
            'debug' => $debug,
            'strict_variables' => $debug,
            'auto_reload' => $debug,
        ]);

        // Set up the Translation component
        $translator = new Translator('en');
        $translator->addLoader('xlf', new XliffFileLoader());
        $translator->addResource('xlf', VENDOR_FORM_DIR . '/Resources/translations/validators.en.xlf', 'en', 'validators');
        $translator->addResource('xlf', VENDOR_VALIDATOR_DIR . '/Resources/translations/validators.en.xlf', 'en', 'validators');

        $formEngine = new TwigRendererEngine(array(DEFAULT_FORM_THEME));
        $formEngine->setEnvironment($environment);

        $environment->addExtension(new TranslationExtension($translator));

        $environment->addExtension(
            new FormExtension(new TwigRenderer($formEngine))
        );

        if ($debug) {
            $environment->addExtension(new DebugExtension());
        }

        $environment->addExtension($container->get(RouteExtension::class));

        foreach ($config['extensions'] as $extension) {
            $environment->addExtension($container->get($extension));
        }

        return $environment;
    }
}