Allow to have different serialization groups for root resource and embedded relations

ItemJsonNormalizer.php

<?php

namespace Emma\AppBundle\Serializer;

use ApiPlatform\Core\Util\ClassInfoTrait;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;
use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
use Symfony\Component\Serializer\Normalizer\NormalizerInterface;

/**
 * Copy from \ApiPlatform\Core\JsonLd\Serializer\ItemJsonNormalizer
 */
class ItemJsonNormalizer implements NormalizerInterface, DenormalizerInterface
{
    use ClassInfoTrait;

    private const ENTRY_POINT_OBJECT_GROUP_KEY = '_entry_point_object';
    private const NOT_ENTRY_POINT_OBJECT_GROUP_KEY = 'not' . self::ENTRY_POINT_OBJECT_GROUP_KEY;

    /**
     * @var NormalizerInterface
     */
    private $normalizer;

    /**
     * @var EventDispatcherInterface
     */
    private $eventDispatcher;

    /**
     * CustomItemNormalizer constructor.
     *
     * @param $normalizer NormalizerInterface
     * @param $eventDispatcher EventDispatcherInterface
     */
    public function __construct(NormalizerInterface $normalizer, EventDispatcherInterface $eventDispatcher)
    {
        if (!$normalizer instanceof DenormalizerInterface) {
            throw new \InvalidArgumentException('The normalizer must implement the DenormalizerInterface');
        }

        $this->normalizer = $normalizer;
        $this->eventDispatcher = $eventDispatcher;

    }

    /**
     * {@inheritdoc}
     */
    public function denormalize($data, $class, $format = null, array $context = array())
    {
        return $this->normalizer->denormalize($data, $class, $format, $context);
    }

    /**
     * {@inheritdoc}
     */
    public function supportsDenormalization($data, $type, $format = null)
    {
        return $this->normalizer->supportsDenormalization($data, $type, $format);
    }

    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = null, array $context = array())
    {
        $this->appendEntryPointObjectGroups($context);

        $context['cache_key'] = md5(json_encode($context['groups']));

        if (!empty($context['parent_property']) && isset($context['property_path'])) {
            $context['property_path'][] = explode('::', $context['parent_property'])[1];
        } elseif (!empty($context['parent_property'])) {
            $context['property_path'] = [explode('::', $context['parent_property'])[1]];
        }

        $data = $this->normalizer->normalize($object, $format, $context);  

        return $data;
    }

    /**
     * {@inheritdoc}
     */
    public function supportsNormalization($data, $format = null)
    {
        return $this->normalizer->supportsNormalization($data, $format);
    }

    /**
     * @param $context
     */
    private function appendEntryPointObjectGroups(&$context)
    {
        if ($context['operation_type'] === 'subresource') {
            return;
        }

        if (!isset($context['parent_property'])) {
            foreach ($context['groups'] as $group) {
                $context['groups'][]  = $group . self::ENTRY_POINT_OBJECT_GROUP_KEY;
            }
        } else {
            foreach ($context['groups'] as $key => $group) {
                if (strpos($group, self::ENTRY_POINT_OBJECT_GROUP_KEY) !== false) {
                    unset($context['groups'][$key]);
                }
                if (strpos($group, self::NOT_ENTRY_POINT_OBJECT_GROUP_KEY) === false) {
                    $context['groups'][]  = $group . self::NOT_ENTRY_POINT_OBJECT_GROUP_KEY;
                }
            }
        }
    }
}

ItemNormalizer.php

<?php

declare(strict_types=1);

namespace Emma\AppBundle\Serializer;

use ApiPlatform\Core\Api\IriConverterInterface;
use ApiPlatform\Core\Api\ResourceClassResolverInterface;
use ApiPlatform\Core\JsonLd\ContextBuilderInterface;
use ApiPlatform\Core\Metadata\Property\Factory\PropertyMetadataFactoryInterface;
use ApiPlatform\Core\Metadata\Property\Factory\PropertyNameCollectionFactoryInterface;
use ApiPlatform\Core\Metadata\Property\PropertyMetadata;
use ApiPlatform\Core\Metadata\Resource\Factory\ResourceMetadataFactoryInterface;
use ApiPlatform\Core\Serializer\AbstractItemNormalizer;
use ApiPlatform\Core\JsonLd\Serializer\JsonLdContextTrait;
use ApiPlatform\Core\Serializer\ContextTrait;
use ApiPlatform\Core\Util\ClassInfoTrait;
use Symfony\Component\PropertyAccess\Exception\NoSuchPropertyException;
use Symfony\Component\PropertyAccess\PropertyAccessorInterface;
use Symfony\Component\Serializer\Exception\LogicException;
use Symfony\Component\Serializer\Exception\NotNormalizableValueException;
use Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactoryInterface;
use Symfony\Component\Serializer\NameConverter\NameConverterInterface;
use Symfony\Component\Serializer\Normalizer\NormalizerInterface;

/**
 * Copy from \ApiPlatform\Core\JsonLd\Serializer\ItemNormalizer
 */
final class ItemNormalizer extends AbstractItemNormalizer
{
    use ClassInfoTrait;
    use ContextTrait;
    use JsonLdContextTrait;

    public const FORMAT = 'jsonld';

    private $contextBuilder;

    public function __construct(ResourceMetadataFactoryInterface $resourceMetadataFactory, PropertyNameCollectionFactoryInterface $propertyNameCollectionFactory, PropertyMetadataFactoryInterface $propertyMetadataFactory, IriConverterInterface $iriConverter, ResourceClassResolverInterface $resourceClassResolver, ContextBuilderInterface $contextBuilder, PropertyAccessorInterface $propertyAccessor = null, NameConverterInterface $nameConverter = null, ClassMetadataFactoryInterface $classMetadataFactory = null, array $defaultContext = [], iterable $dataTransformers = [])
    {
        parent::__construct($propertyNameCollectionFactory, $propertyMetadataFactory, $iriConverter, $resourceClassResolver, $propertyAccessor, $nameConverter, $classMetadataFactory, null, false, $defaultContext, $dataTransformers, $resourceMetadataFactory);

        $this->contextBuilder = $contextBuilder;
    }

    /**
     * {@inheritdoc}
     */
    public function supportsNormalization($data, $format = null): bool
    {
        return self::FORMAT === $format && parent::supportsNormalization($data, $format);
    }

    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = null, array $context = [])
    {
        if (null !== $this->getOutputClass($this->getObjectClass($object), $context)) {
            return parent::normalize($object, $format, $context);
        }

        $resourceClass = $this->resourceClassResolver->getResourceClass($object, $context['resource_class'] ?? null);
        $context = $this->initContext($resourceClass, $context);
        $iri = $this->iriConverter->getIriFromItem($object);
        $context['iri'] = $iri;
        $context['api_normalize'] = true;

        $metadata = $this->addJsonLdContext($this->contextBuilder, $resourceClass, $context);

        $context['resource_class'] = $resourceClass;

        $data = parent::normalize($object, $format, $context);
        if (!\is_array($data)) {
            return $data;
        }

        $resourceMetadata = $this->resourceMetadataFactory->create($resourceClass);

        $metadata['@id'] = $iri;
        $metadata['@type'] = $resourceMetadata->getIri() ?: $resourceMetadata->getShortName();

        return $metadata + $data;
    }

    /**
     * {@inheritdoc}
     */
    public function supportsDenormalization($data, $type, $format = null): bool
    {
        return self::FORMAT === $format && parent::supportsDenormalization($data, $type, $format);
    }

    /**
     * {@inheritdoc}
     *
     * @throws NotNormalizableValueException
     */
    public function denormalize($data, $class, $format = null, array $context = [])
    {
        // Avoid issues with proxies if we populated the object
        if (isset($data['@id']) && !isset($context[self::OBJECT_TO_POPULATE])) {
            if (true !== ($context['api_allow_update'] ?? true)) {
                throw new NotNormalizableValueException('Update is not allowed for this operation.');
            }

            $context[self::OBJECT_TO_POPULATE] = $this->iriConverter->getItemFromIri($data['@id'], $context + ['fetch_data' => true]);
        }

        return parent::denormalize($data, $class, $format, $context);
    }

    /**
     * {@inheritdoc}
     *
     * @throws NoSuchPropertyException
     */
    protected function getAttributeValue($object, $attribute, $format = null, array $context = [])
    {
        $context['api_attribute'] = $attribute;
        $propertyMetadata = $this->propertyMetadataFactory->create($context['resource_class'], $attribute, $this->getFactoryOptions($context));

        try {
            $attributeValue = $this->propertyAccessor->getValue($object, $attribute);
        } catch (NoSuchPropertyException $e) {
            if (!$propertyMetadata->hasChildInherited()) {
                throw $e;
            }

            $attributeValue = null;
        }

        $type = $propertyMetadata->getType();

        if (
            is_iterable($attributeValue) &&
            $type &&
            $type->isCollection() &&
            ($collectionValueType = $type->getCollectionValueType()) &&
            ($className = $collectionValueType->getClassName()) &&
            $this->resourceClassResolver->isResourceClass($className)
        ) {
            $resourceClass = $this->resourceClassResolver->getResourceClass($attributeValue, $className);
            $childContext = $this->createChildContext($context, $attribute, $format);
            $childContext['resource_class'] = $resourceClass;
            unset($childContext['iri']);

            // LOCC START
            $context['parent_property'] = $this->getObjectClass($object) . '::'.$attribute;
            // LOCC END

            return $this->normalizeCollectionOfRelations($propertyMetadata, $attributeValue, $resourceClass, $format, $childContext);
        }

        if (
            $type &&
            ($className = $type->getClassName()) &&
            $this->resourceClassResolver->isResourceClass($className)
        ) {
            $resourceClass = $this->resourceClassResolver->getResourceClass($attributeValue, $className);
            $childContext = $this->createChildContext($context, $attribute, $format);
            $childContext['resource_class'] = $resourceClass;
            unset($childContext['iri']);

            // LOCC START
            $context['parent_property'] = $this->getObjectClass($object) . '::'.$attribute;
            // LOCC END

            return $this->normalizeRelation($propertyMetadata, $attributeValue, $resourceClass, $format, $childContext);
        }

        if (!$this->serializer instanceof NormalizerInterface) {
            throw new LogicException(sprintf('The injected serializer must be an instance of "%s".', NormalizerInterface::class));
        }

        unset($context['resource_class']);

        return $this->serializer->normalize($attributeValue, $format, $context);
    }

    /**
     * @inheritDoc
     */
    protected function normalizeCollectionOfRelations(PropertyMetadata $propertyMetadata, $attributeValue, string $resourceClass, ?string $format, array $context): array
    {
        return array_values(
            parent::normalizeCollectionOfRelations($propertyMetadata, $attributeValue, $resourceClass, $format, $context)
        );
    }
}

services.yml

api.serializer.normalizer.item:
    public: false
    class: Emma\AppBundle\Serializer\ItemNormalizer
    arguments: [ '@api.serializer.normalizer.item.json', '@event_dispatcher']
    tags: [ { name: serializer.normalizer, priority: 9 } ]

api.serializer.normalizer.item.json:
  public: false
  class: Emma\AppBundle\Serializer\ItemJsonNormalizer
  arguments:
    - '@api_platform.metadata.resource.metadata_factory'
    - '@api_platform.metadata.property.name_collection_factory'
    - '@api_platform.metadata.property.metadata_factory'
    - '@api_platform.iri_converter'
    - '@api_platform.resource_class_resolver'
    - '@api_platform.jsonld.context_builder'
    - '@api_platform.property_accessor'
    - ~
    - '@serializer.mapping.class_metadata_factory'
  tags: [ { name: serializer.normalizer, priority: 8 } ]