RelationshipNormalizer.php

<?php

namespace Drupal\jsonapi\Normalizer;

use Drupal\jsonapi\JsonApiResource\Relationship;
use Drupal\jsonapi\Normalizer\Value\CacheableNormalization;

/**
 * Normalizes a JSON:API relationship object.
 *
 * @internal
 */
class RelationshipNormalizer extends NormalizerBase {
    
    /**
     * {@inheritdoc}
     */
    protected $supportedInterfaceOrClass = Relationship::class;
    
    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = NULL, array $context = []) {
        assert($object instanceof Relationship);
        return CacheableNormalization::aggregate([
            'data' => $this->serializer
                ->normalize($object->getData(), $format, $context),
            'links' => $this->serializer
                ->normalize($object->getLinks(), $format, $context)
                ->omitIfEmpty(),
            'meta' => CacheableNormalization::permanent($object->getMeta())
                ->omitIfEmpty(),
        ]);
    }

}