Symfony Form Flow Expectation

form.html.twig

{% extends 'base.html.twig' %}

{% block body %}
    {{ form(form) }}
{% endblock %}

RegisterUserController.php

<?php

namespace App\Controller;

use App\Form\Type\RegisterUserType;
use App\Model\UserDto;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Form\FormFlowFactoryInterface;
use Symfony\Component\Routing\Attribute\Route;

class RegisterUserController extends AbstractController
{
    public function __invoke(Request $request, FormFlowFactoryInterface $factory): Response
    {
        $flow = $factory->create(RegisterUserType::class, new UserDto());
        $flow->handleRequest($request);

        if ($flow->isSubmitted() && $flow->isValid() && $flow->isCompleted()) {
            dd($flow->getData());
        }

        return $this->render('form.html.twig', [
            'form' => $flow->getForm(),
        ]);
    }
}

RegisterUserType.php

<?php

namespace App\Form\Type;

use App\Model\UserDto;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\FormFlowType;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;

class RegisterUserType extends AbstractType
{
    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults([
            'steps' => [
                'personal' => UserPersonalType::class,
                'professional' => UserProfessionalType::class,
                'extra' => function (FormBuilderInterface $builder) {
                    $builder->add('position', TextType::class, ['required' => false]);
                },
                'credential' => UserCredentialType::class,
            ],
            'current_step_property_path' => 'currentStep',
            'data_class' => UserDto::class,
        ]);
    }

    public function getParent(): string
    {
        return FormFlowType::class;
    }
}

UserDto.php

<?php

namespace App\Model;

use Symfony\Component\Validator\Constraints as Assert;

class UserDto
{
    // personal step
    #[Assert\NotBlank(groups: ['personal'])]
    public ?string $firstName = null;
    public ?string $lastName = null;
    #[Assert\GreaterThanOrEqual(18, groups: ['personal'])]
    public ?int $age = null;
    public bool $enterprise = false;

    // professional step
    #[Assert\NotBlank(groups: ['professional'])]
    public ?string $company = null;
    public ?string $position = null;

    // credentials step
    #[Assert\NotBlank(groups: ['credential'])]
    #[Assert\Email(groups: ['credential'])]
    public ?string $email = null;
    #[Assert\NotBlank(groups: ['credential'])]
    #[Assert\PasswordStrength(minScore: Assert\PasswordStrength::STRENGTH_WEAK, groups: ['credential'])]
    public ?string $plainPassword = null;

    public string $currentStep = 'personal';
}