CategoryType

<?php

  namespace App\Form;

  use App\Entity\Category;
  use App\Form\DataTransformer\CategoryToNumberTransformer;
  use Symfony\Bridge\Doctrine\Form\Type\EntityType;
  use Symfony\Component\Form\AbstractType;
  use Symfony\Component\Form\Extension\Core\Type\FileType;
  use Symfony\Component\Form\Extension\Core\Type\SubmitType;
  use Symfony\Component\Form\Extension\Core\Type\TextareaType;
  use Symfony\Component\Form\Extension\Core\Type\TextType;
  use Symfony\Component\Form\FormBuilderInterface;
  use Symfony\Component\OptionsResolver\OptionsResolver;

  class CategoryType extends AbstractType
  {
    /**
     * @var \App\Form\DataTransformer\RoleToNumberTransformer
     */
    private $transformer;

    public function __construct(CategoryToNumberTransformer $transformer) {
      $this->transformer = $transformer;
    }

    public function buildForm(FormBuilderInterface $builder, array $options)
    {

      $builder
        ->add('name', TextType::class, ['attr' => ['class' => 'form-control', 'autocomplete' => 'off']])
        ->add('thumbnail', FileType::class, ['data_class' => null, 'required'   => false, 'empty_data' => null, 'attr' => ['class' => 'form-control-file', 'autocomplete' => 'off']])

        ->add('parentCategory', EntityType::class, [
          'class'         => Category::class,
          'placeholder'   => 'None',
          'empty_data'    => $options['data']->getParentCategory() ,
          'required'      => false,
          'multiple'      => false,
          'expanded'      => false,
          'choice_label'  => function ($parentCat) { return $parentCat->getName();}
        ])

        ->add('description', TextareaType::class, ['required' => false, 'label'  => 'Description', 'attr' => ['class' => 'form-control', 'autocomplete' => 'off']])
        ->add('save', SubmitType::class, ['attr' => ['class' => 'btn btn-primary']])
      ;
    }

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