Image uploader form type

<?php

namespace AppBundle\Form\Type;

use Domain\Bundle\ImageBundle\Service\ImageManager;
use Domain\Bundle\ImageBundle\Service\RackspaceImageDisplay;
use AppBundle\Form\DataTransformer\DomainImageTransformer;
use AppBundle\Validator\Constraints\DomainFlexibleImage;
use AppBundle\Validator\Constraints\DomainImage;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\FileType;
use Symfony\Component\Form\Extension\Core\Type\FormType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormEvents;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Form\FormView;
use Symfony\Component\OptionsResolver\Options;
use Symfony\Component\OptionsResolver\OptionsResolver;

class DomainImageType extends AbstractType
{
    /** @var ImageManager */
    private $imageManager;

    /** @var RackspaceImageDisplay */
    private $rackspaceImageDisplay;

    /** @var array */
    private $preSetData;

    /**
     * @param ImageManager $imageManager
     */
    public function setImageManager(ImageManager $imageManager)
    {
        $this->imageManager = $imageManager;
    }

    /**
     * @param RackspaceImageDisplay $rackspaceManager
     */
    public function setRackspaceImageDisplay(RackspaceImageDisplay $rackspaceManager)
    {
        $this->rackspaceImageDisplay = $rackspaceManager;
    }

    /**
     * {@inheritdoc}
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        if ($options['isRemovable']) {
            // Remove checkbox that will tell us when we want to remove the image
            $builder->add('remove', CheckboxType::class, ['required' => false]);
        }

        $builder->add(
            'file',
            FileType::class,
            [
                'constraints' => $options['image_constraint'],
                'required' => $options['image_required'],
                'help_label' => $options['help_label'],
                'attr' => [
                    'accept' => 'image/*', // tell mobile phones to use gallery app to select a photo
                ],
            ]
        );

        $transformer = new DomainImageTransformer(
            $this->imageManager,
            $options['pretty-name'],
            $options['storageAlias']
        );
        $builder
            ->get('file')
            ->addModelTransformer($transformer);

        $builder->addEventListener(FormEvents::PRE_SET_DATA, [$this, 'onPreSetData']);
        $builder->addEventListener(FormEvents::SUBMIT, [$this, 'onSubmit']);
    }

    /**
     * This is done for BC where data is the direct file path
     *
     * @param FormEvent $formEvent
     */
    public function onPreSetData(FormEvent $formEvent)
    {
        $data = $formEvent->getData();
        if (!is_array($data)) {
            $data = [
                'file' => $data
            ];
        }

        $this->preSetData[] = $data;
        $formEvent->setData($data);
    }

    /**
     * For BC send just the string
     *
     * @param FormEvent $formEvent
     */
    public function onSubmit(FormEvent $formEvent)
    {
        $data = $formEvent->getData();
        $preSetData = array_shift($this->preSetData);

        if (!empty($data['remove'])) {
            // We want to remove the file
            $data = null;
        } elseif (null === $data['file']) {
            // Persist the same file
            $data = $preSetData['file'];
        } else {
            $data = $data['file'];
        }

        $formEvent->setData($data);
    }

    /**
     * {@inheritdoc}
     */
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(
            [
                // Preview settings, to render the image on the template
                'preview' => false,
                // If set to true a checkbox will also be rendered when ticked this is removed
                'isRemovable' => false,
                // Tells which storage to use, leave null for default
                'storageAlias' => null,
                // Image constraint
                'image_constraint' => new DomainImage(),
                // Image required
                'image_required' => false,
            ]
        );

        $resolver->setRequired(['pretty-name']);
    }

    /**
     * @see sf2/app/Resources/views/shared/form/fields.html.twig:140
     *
     * {@inheritdoc}
     */
    public function buildView(FormView $view, FormInterface $form, array $options)
    {
        $thumbnail = $this->rackspaceImageDisplay->getUrl($form->get('file')->getData(), true);
        $view->vars = array_replace(
            $view->vars,
            [
                'thumbnail' => $thumbnail,
                'preview' => $options['preview'],
                'isRemovable' => $options['isRemovable'],
            ]
        );
    }

    /**
     * {@inheritdoc}
     */
    public function getParent()
    {
        return FormType::class;
    }
}