Symfony 3.3 Checkbox only form not submitted - php

Question

I want to have a form submitted by javascript that contains only one checkbox. But since empty checkboxes don't send their key in request, Symfony doesn't know about the form being submitted. So is there any not so hacky solution or is this kind of a "bug".
form:
class NewsletterType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('subscribingNewsletter', CheckboxType::class, [
'label' => 'form.label.newsletter',
'required' => false,
]);
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'data_class' => User::class,
]);
}
}
part of the controller:
$newsletterForm = $this->formFactory->create(NewsletterType::class, $userToEdit);
$newsletterForm->handleRequest($request);
if ($this->newsletterFormHandler->handle($newsletterForm)) {
$this->session->getFlashBag()->add('notice', 'flash_message.newsletter_changed');
return $response;
}
handler:
public function handle(FormInterface $form): bool
{
if (!$form->isSubmitted() || !$form->isValid()) {
return false;
}
$this->userManager->update($form->getData());
return true;
}
view:
{{ form_start(NewsletterForm) }}
{{ form_row(NewsletterForm.subscribingNewsletter, {
attr: {class: 'js-newsletter-toggle'}
}) }}
{{ form_end(NewsletterForm) }}

Answer 1

So I finally resolved this issue. The only way I found to get this working is to add your submit button to your code like this:
class NewsletterType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('subscribingNewsletter', CheckboxType::class, [
'label' => 'form.label.newsletter',
'required' => false,
])
->add('submit', SubmitType::class);
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'data_class' => User::class,
]);
}
}
Not in your view. I was submitting the form by javascript so the way to to this is to simulate the button click in js.