How can I add a violation to a collection?

Question

My form looks like this:

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $factory = $builder->getFormFactory();

    $build         


        

Answer 1

I have a case very similar. I have a CollectionType with a Custom Form (with DataTransformers inside, etc...), i need check one by one the elements and mark what of them is wrong and print it on the view.

I make that solution at the ConstraintValidator (my custom validator):

The validator must target to CLASS_CONSTRAINT to work or the propertyPath doesnt work.

public function validate($value, Constraint $constraint) {
    /** @var Form $form */
    $form = $this->context->getRoot();
    $studentsForm = $form->get("students"); //CollectionType's name in the root Type
    $rootPath = $studentsForm->getPropertyPath()->getElement(0);

    /** @var Form $studentForm */
    foreach($studentsForm as $studentForm){
        //Iterate over the items in the collection type
        $studentPath = $studentForm->getPropertyPath()->getElement(0);

        //Get the data typed on the item (in my case, it use an DataTransformer and i can get an User object from the child TextType)
        /** @var User $user */
        $user = $studentForm->getData();

        //Validate your data
        $email = $user->getEmail();
        $user = $userRepository->findByEmailAndCentro($email, $centro);

        if(!$user){
            //If your data is wrong build the violation from the propertyPath getted from the item Type
            $this->context->buildViolation($constraint->message)
                ->atPath($rootPath)
                ->atPath(sprintf("[%s]", $studentPath))
                ->atPath("email") //That last is the name property on the item Type
                ->addViolation();
        }
    }
}

Just i validate agains the form elements in the collection and build the violation using the propertyPath from the item in the collection that is wrong.