Symfony form common fields inheritance/composition

Question

I have 2 entities A and B that share common fields, I used a trait to setup those common fields based on (Doctrine inheritance for entities common fields) because I don't want to use a MappedSuperClass.

Setting up a restful post route for entity B, I instantiate a FormBType which data_class maps to B::class, that extends FormCType (contains common fields and 'data_class' maps to nothing).

I tried to use the inherit_data approach with https://symfony.com/doc/current/form/inherit_data_option.html but I don't want that extra key/nested layer in my form (I want a flattened one).

My problem is that validation for the common fields which are in the trait using Assert aren't taken into account and form passes validation with empty strings.

class B {
use CTrait;
}


//trait that has the common fields with ORM mapping and Assert
trait CTrait {
/**
* @ORM\Id
* @ORM\GeneratedValue
* @ORM\Column(type="integer")
*/
private $id;

/**
* @ORM\Column(type="string")
* @ORM\Assert\Length(min="2")
*/
private $name;
}


//Common fields formType
class CType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('name');
    }
}

//Form using the common fields formType
class BType extends CType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        parent::buildForm($builder, $options);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'data_class' => B::class,
            'csrf_protection' => false,
        ]);
    }
}

Answer 1

After further checking on Length I realized empty strings are considered valid values and it was still passing through validation using name: "" even though I had Assert\Length(min=2), after adding NotBlank the validation worked.