TypedDataNormalizer.php

<?php

namespace Drupal\serialization\Normalizer;

use Drupal\Core\TypedData\TypedDataInterface;

/**
 * Converts typed data objects to arrays.
 */
class TypedDataNormalizer extends NormalizerBase {
    
    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = NULL, array $context = []) : array|string|int|float|bool|\ArrayObject|null {
        $this->addCacheableDependency($context, $object);
        $value = $object->getValue();
        // Support for stringable value objects: avoid numerous custom normalizers.
        if (is_object($value) && method_exists($value, '__toString')) {
            $value = (string) $value;
        }
        return $value;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSupportedTypes(?string $format) : array {
        return [
            TypedDataInterface::class => TRUE,
        ];
    }

}