class EntityDenormalizerBase

abstract class EntityDenormalizerBase extends NormalizerBase implements DenormalizerInterface {
    
    /**
     * The JSON:API resource type repository.
     *
     * @var \Drupal\jsonapi\ResourceType\ResourceTypeRepositoryInterface
     */
    protected $resourceTypeRepository;
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The entity field manager.
     *
     * @var \Drupal\Core\Entity\EntityFieldManagerInterface
     */
    protected $fieldManager;
    
    /**
     * The field plugin manager.
     *
     * @var \Drupal\Core\Field\FieldTypePluginManagerInterface
     */
    protected $pluginManager;
    
    /**
     * Constructs an EntityDenormalizerBase object.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     * @param \Drupal\Core\Entity\EntityFieldManagerInterface $field_manager
     *   The entity field manager.
     * @param \Drupal\Core\Field\FieldTypePluginManagerInterface $plugin_manager
     *   The plugin manager for fields.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $field_manager, FieldTypePluginManagerInterface $plugin_manager) {
        $this->entityTypeManager = $entity_type_manager;
        $this->fieldManager = $field_manager;
        $this->pluginManager = $plugin_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public function supportsNormalization($data, $format = NULL) {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = NULL, array $context = []) {
        throw new \LogicException('This method should never be called.');
    }
    
    /**
     * {@inheritdoc}
     */
    public function denormalize($data, $class, $format = NULL, array $context = []) {
        if (empty($context['resource_type']) || !$context['resource_type'] instanceof ResourceType) {
            throw new PreconditionFailedHttpException('Missing context during denormalization.');
        }
        
        /** @var \Drupal\jsonapi\ResourceType\ResourceType $resource_type */
        $resource_type = $context['resource_type'];
        $entity_type_id = $resource_type->getEntityTypeId();
        $bundle = $resource_type->getBundle();
        $bundle_key = $this->entityTypeManager
            ->getDefinition($entity_type_id)
            ->getKey('bundle');
        if ($bundle_key && $bundle) {
            $data[$bundle_key] = $bundle;
        }
        return $this->entityTypeManager
            ->getStorage($entity_type_id)
            ->create($this->prepareInput($data, $resource_type, $format, $context));
    }
    
    /**
     * Prepares the input data to create the entity.
     *
     * @param array $data
     *   The input data to modify.
     * @param \Drupal\jsonapi\ResourceType\ResourceType $resource_type
     *   Contains the info about the resource type.
     * @param string $format
     *   Format the given data was extracted from.
     * @param array $context
     *   Options available to the denormalizer.
     *
     * @return array
     *   The modified input data.
     */
    protected abstract function prepareInput(array $data, ResourceType $resource_type, $format, array $context);

}