Form field is set to NULL, even when not neccessary

[cklm]

Thank you very much for this package - it might change how we work with forms forever ;)

Version is current v0.1.3, symfony is at 6.4.

When testing I found a bug: I bound an entity to the DynamicFormBuilder:

// App\Entity\User
class User {

    public const int TYPE_USER = 1;
    public const int TYPE_ADMIN = 2;
    
    protected int $type=self::TYPE_USER;

    public function setType(int $type): static
    {
        $this->type = $type;

        return $this;
    }
}


// App\Form\UserType
class UserType extends AbstractType
{

    public function buildForm(FormBuilderInterface $builder, array $options): void
    {

        $builder = new DynamicFormBuilder($builder);
        $builder->add('choice',CheckboxType::class, [
            'label' => 'select type?',
            'required' => false,
            'mapped' => false,
        ]);

        $builder->addDependent('type',['choice'],static function(DependentField $field, ?bool $choice) {
            if($choice===false) {
                return;
            }

            $field->add(ChoiceType::class, [
                'label' => 'Typ',
                'choices' => User::TYPES,
                'constraints' => [],
            ]);
        });
    }
}

When the user now ticks select type? the form rerenders and throws an exception: Expected argument of type "int", "null" given at property path "type".. $form->submit() in ComponentWithFormTrait.php tries to map the (empty) data to the entity and therefore tries to set $type to NULL. Workaround is to allow NULL in setType(), but then to ignore it. Otherwise use a dto for the form and later transfer it to the entity.

Complete stacktrace:

TypeError:
App\Entity\User::setType(): Argument #1 ($type) must be of type int, null given, called in C:\projekte\test-project\vendor\symfony\property-access\PropertyAccessor.php on line 543
at C:\projekte\test-project\src\Entity\User.php:221
at App\Entity\User->setType(null)
(C:\projekte\test-project\vendor\symfony\property-access\PropertyAccessor.php:543)
at Symfony\Component\PropertyAccess\PropertyAccessor->writeProperty(array(object(User)), 'type', null)
(C:\projekte\test-project\vendor\symfony\property-access\PropertyAccessor.php:120)
at Symfony\Component\PropertyAccess\PropertyAccessor->setValue(object(User), object(PropertyPath), null)
(C:\projekte\test-project\vendor\symfony\form\Extension\Core\DataAccessor\PropertyPathAccessor.php:75)
at Symfony\Component\Form\Extension\Core\DataAccessor\PropertyPathAccessor->setValue(object(User), null, object(Form))
(C:\projekte\test-project\vendor\symfony\form\Extension\Core\DataAccessor\ChainAccessor.php:48)
at Symfony\Component\Form\Extension\Core\DataAccessor\ChainAccessor->setValue(object(User), null, object(Form))
(C:\projekte\test-project\vendor\symfony\form\Extension\Core\DataMapper\DataMapper.php:74)
at Symfony\Component\Form\Extension\Core\DataMapper\DataMapper->mapFormsToData(object(RecursiveIteratorIterator), object(User))
(C:\projekte\test-project\vendor\symfony\form\Form.php:551)
at Symfony\Component\Form\Form->submit(array())
(C:\projekte\test-project\vendor\symfony\ux-live-component\src\ComponentWithFormTrait.php:155)
at App\Twig\Components\UserTest->submitForm(false)
(C:\projekte\test-project\vendor\symfony\ux-live-component\src\ComponentWithFormTrait.php:111)
at App\Twig\Components\UserTest->submitFormOnRender()
(C:\projekte\test-project\vendor\symfony\ux-live-component\src\EventListener\LiveComponentSubscriber.php:328)
at Symfony\UX\LiveComponent\EventListener\LiveComponentSubscriber->createResponse(object(MountedComponent))
(C:\projekte\test-project\vendor\symfony\ux-live-component\src\EventListener\LiveComponentSubscriber.php:258)
at Symfony\UX\LiveComponent\EventListener\LiveComponentSubscriber->onKernelView(object(ViewEvent), 'kernel.view', object(TraceableEventDispatcher))
(C:\projekte\test-project\vendor\symfony\event-dispatcher\Debug\WrappedListener.php:116)
at Symfony\Component\EventDispatcher\Debug\WrappedListener->__invoke(object(ViewEvent), 'kernel.view', object(TraceableEventDispatcher))
(C:\projekte\test-project\vendor\symfony\event-dispatcher\EventDispatcher.php:220)
at Symfony\Component\EventDispatcher\EventDispatcher->callListeners(array(object(WrappedListener), object(WrappedListener)), 'kernel.view', object(ViewEvent))
(C:\projekte\test-project\vendor\symfony\event-dispatcher\EventDispatcher.php:56)
at Symfony\Component\EventDispatcher\EventDispatcher->dispatch(object(ViewEvent), 'kernel.view')
(C:\projekte\test-project\vendor\symfony\event-dispatcher\Debug\TraceableEventDispatcher.php:139)
at Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcher->dispatch(object(ViewEvent), 'kernel.view')
(C:\projekte\test-project\vendor\symfony\http-kernel\HttpKernel.php:186)
at Symfony\Component\HttpKernel\HttpKernel->handleRaw(object(Request), 1)
(C:\projekte\test-project\vendor\symfony\http-kernel\HttpKernel.php:76)
at Symfony\Component\HttpKernel\HttpKernel->handle(object(Request), 1, true)
(C:\projekte\test-project\vendor\symfony\http-kernel\Kernel.php:197)
at Symfony\Component\HttpKernel\Kernel->handle(object(Request))
(C:\projekte\test-project\vendor\symfony\runtime\Runner\Symfony\HttpKernelRunner.php:35)
at Symfony\Component\Runtime\Runner\Symfony\HttpKernelRunner->run()
(C:\projekte\test-project\vendor\autoload_runtime.php:29)
at require_once('C:\\projekte\\test-project\\vendor\\autoload_runtime.php')
(C:\projekte\test-project\public\index.php:5)

Am I missing something? Through the setting to NULL the default value of $type is also lost. Adding 'data' => User::TYPE_USER, does not prevent the exception.

[cklm]

Just found out, that the problem is already known in symfony/ux. The PR at symfony/ux#2397 solves the problem for me.