问Symfony:通过依赖注入在formType中使用DataTransformer

EN

services:
lion_visionomie_media_bundle_base64_data_transformer:
    class: Lion\Visionomie\MediaBundle\Transformer\Base64DataTransformer
    arguments: ['@sonata.media.generator.default', '@sonata.media.manager.media', '@sonata.media.pool', '@doctrine.orm.entity_manager']

lion_visionomie_media_bundle_slide_type:
    class: Lion\Visionomie\MediaBundle\Form\SlideType
    arguments: ['@lion_visionomie_media_bundle_base64_data_transformer']
    tags:
        - {name: form.type}

class Base64DataTransformer implements DataTransformerInterface
{
/**
 * @var GeneratorInterface
 */
private $pathGenerator;

/**
 * @var MediaManager
 */
private $mediaManager;

/**
 * @var Pool
 */
private $pool;

/**
 * @var EntityManagerInterface
 */
private $entityManager;

public function __construct(GeneratorInterface $generator, MediaManager $mediaManager, Pool $pool, EntityManagerInterface $entityManager)
{
    $this->pathGenerator = $generator;
    $this->mediaManager = $mediaManager;
    $this->pool = $pool;
    $this->entityManager = $entityManager;
}

/**
 * @param mixed $value
 * @return mixed
 */
public function transform($value)
{
    // [...]
    return $media;
}

/**
 * @param mixed $value
 * @return mixed
 */
public function reverseTransform($value)
{
    /** @var Media $media */
    $media = $value;

    return base64_encode(file_get_contents($media->getPreviousProviderReference()));
}
}

class SlideType extends AbstractType
{
/**
 * @var Base64DataTransformer
 */
private $base64DataTransformer;

public function __construct(Base64DataTransformer $base64DataTransformer)
{
    dump($base64DataTransformer);
    die;
    $this->base64DataTransformer = $base64DataTransformer;
}

/**
 * @param FormBuilderInterface $builder
 * @param array $options
 */
public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
        ->add('name')
        ->add('active')
        ->add('background')
            ->addModelTransformer($this->base64DataTransformer)
        ->add('thumbnail')

    ;
}