Symfony 4 - isValid always returns false - php

Question

I'm trying to validate my form by using $form->isValid(). But even if my form is correct it returns false. I already tried to dump my errors with $form->getErrors(true) but then my request times out.
My CreateController.php:
class CreateController extends Controller
{
/**
* #Method({"POST"})
* #Route("/api/v1/matches", name="api_v1_matches_create")
*/
public function index(Request $request, EntityManagerInterface $em): JsonResponse
{
$data = json_decode($request->getContent(), true);
$match = new Match();
$form = $this->createForm(MatchFormType::class, $match);
$form->submit($data);
if ($form->isValid()) {
$em->persist($match);
$em->flush();
return new JsonResponse(null, 201);
} else {
return new JsonResponse(null, 400);
}
}
}
My Form.php
class MatchFormType extends AbstractType
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add(
'heroes',
EntityType::class,
[
'class' => Hero::class,
]
)
->add(
'season',
EntityType::class,
[
'class' => Season::class,
]
)
->add(
'map',
EntityType::class,
[
'class' => Map::class,
]
);
}
public function getName(): string
{
return 'match';
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'data_class' => Match::class,
]);
}
}
JSON to POST
{
"map": 1,
"heroes": [
1,
2
],
"season": 1
}
Thanks in advance for your help!

Answer 1

I fixed it by adding 'multiple' => true to my heroes entry, so the form knows it's an array and by disable CSRF protection ('csrf_protection' => false as parameter in $resolver).

Answer 2

I believe you may want to follow the practices described in documentation here https://symfony.com/doc/4.1/forms.html#handling-form-submissions
Dividing article example into steps in your case you may want:
Create a new form object
Handle the http request
Check that form is being submitted & is valid
If previous condition is met, get form data & flush it to the db