ComplexDataNormalizer.php

<?php

namespace Drupal\serialization\Normalizer;

use Drupal\Core\TypedData\ComplexDataInterface;
use Drupal\Core\TypedData\TypedDataInternalPropertiesHelper;

/**
 * Converts the Drupal entity object structures to a normalized array.
 *
 * This is the default Normalizer for entities. All formats that have Encoders
 * registered with the Serializer in the DIC will be normalized with this
 * class unless another Normalizer is registered which supersedes it. If a
 * module wants to use format-specific or class-specific normalization, then
 * that module can register a new Normalizer and give it a higher priority than
 * this one.
 */
class ComplexDataNormalizer extends NormalizerBase {
    
    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = NULL, array $context = []) : array|string|int|float|bool|\ArrayObject|null {
        $attributes = [];
        // $object will not always match getSupportedTypes().
        // @see \Drupal\serialization\Normalizer\EntityNormalizer
        // Other normalizers that extend this class may only provide $object that
        // implements \Traversable.
        if ($object instanceof ComplexDataInterface) {
            // If there are no properties to normalize, just normalize the value.
            $object = !empty($object->getProperties(TRUE)) ? TypedDataInternalPropertiesHelper::getNonInternalProperties($object) : $object->getValue();
        }
        
        /** @var \Drupal\Core\TypedData\TypedDataInterface $property */
        foreach ($object as $name => $property) {
            $attributes[$name] = $this->serializer
                ->normalize($property, $format, $context);
        }
        return $attributes;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSupportedTypes(?string $format) : array {
        return [
            ComplexDataInterface::class => TRUE,
        ];
    }

}