php - Passing data to buildForm() in Symfony 2.8, 3.0 and above

Question

My application currently passes data to my form type using the constructor, as recommended in this answer. However the Symfony 2.8 upgrade guide advises that passing a type instance to the createForm function is deprecated:

Passing type instances to Form::add(), FormBuilder::add() and the FormFactory::create*() methods is deprecated and will not be supported anymore in Symfony 3.0. Pass the fully-qualified class name of the type instead.

Before:    
$form = $this->createForm(new MyType());

After:
$form = $this->createForm(MyType::class);

Seeing as I can't pass data through with the fully-qualified class name, is there an alternative?

Answer 1

This broke some of our forms as well. I fixed it by passing the custom data through the options resolver.

In your form type:

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $this->traitChoices = $options['trait_choices'];

    $builder
        ...
        ->add('figure_type', ChoiceType::class, [
            'choices' => $this->traitChoices,
        ])
        ...
    ;
}

public function configureOptions(OptionsResolver $resolver)
{
    $resolver->setDefaults([
        'trait_choices' => null,
    ]);
}

Then when you create the form in your controller, pass it in as an option instead of in the constructor:

$form = $this->createForm(ProfileEditType::class, $profile, [
    'trait_choices' => $traitChoices,
]);