Symfony manually $form->submit(); with multidimensional array - symfony

Question

Im struggling since 10 hours with Symfony 5.1.7 and $form->submit();
My target is a JSON API that converts data to a similiar array. I already debugged and found following part.
Can someone please help me what I am doing wrong here?
To test it, i have created a manually PHP array to submit it.
My Code in Controller
$form = $this->createForm(AddCommentFormType::class);
$test = [
'content' => 'Test',
'media' => [
[
'path' => '1.png',
],
[
'path' => '2.png',
],
],
'_token' => '3bF4qkiUPjKNuGnbY-ySdO6B2sCLzKcS4ar7auX3Dek',
];
$form->submit($test);
AddCommentFormType
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('content', TextareaType::class, [
'constraints' => [
new NotBlank(),
new Length([
'max' => 10000,
]),
],
])
->add('media', CollectionType::class, [
'entry_type' => MediaFormType::class,
'constraints' => [
new Count([
'min' => 1,
'max' => 5,
]),
],
])
->add('_token', HiddenType::class, [
'mapped' => false,
'constraints' => [
new NotBlank(),
],
])
;
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'csrf_protection' => false,
]);
}
MediaFormType
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('path', TextType::class, [
'constraints' => [
new NotBlank(),
],
])
;
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults([
'data_class' => Media::class,
]);
}
Validator Result
children[media].data
This collection should contain 1 element or more.
[]
children[media]
This form should not contain extra fields.
[▼
[▼
"path" => "1.png"
]
[▼
"path" => "2.png"
]
]

Answer 1

your form has no default data, since you create it with
$form = $this->createForm(AddCommentFormType::class);
createForm can take an additional parameter for default data. This alone is not necessarily a problem, the default is an array of the form (or something very similar, maybe empty strings instead of null)
[
'content' => null,
'media' => [],
'_token' => null,
]
However, the CollectionType will not allow adding or removing elements by default. Setting it's options allow_add (and optionally allow_remove, if you ever set default values) will change that.
So the minimal change would be:
->add('media', CollectionType::class, [
'allow_add' => true, // <-- this is new
'entry_type' => MediaFormType::class,
'constraints' => [
new Count([
'min' => 1,
'max' => 5,
]),
],
])

Answer 2

If your type is AddCommentFormType the form expects by default the data to be in add_comment_form keys like:
$test = [
‘add_comment_form’ => [
'content' => 'Test',
'media' => [
[
'path' => '1.png',
],
[
'path' => '2.png',
],
],
'_token' => '3bF4qkiUPjKNuGnbY-ySdO6B2sCLzKcS4ar7auX3Dek',
]
];