PrimitiveDataNormalizer.php

<?php

namespace Drupal\serialization\Normalizer;

use Drupal\Core\Field\FieldItemInterface;
use Drupal\Core\TypedData\PrimitiveInterface;

/**
 * Converts primitive data objects to their casted values.
 */
class PrimitiveDataNormalizer extends NormalizerBase {
    use SerializedColumnNormalizerTrait;
    
    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = NULL, array $context = []) : array|string|int|float|bool|\ArrayObject|null {
        // Add cacheability if applicable.
        $this->addCacheableDependency($context, $object);
        $parent = $object->getParent();
        if ($parent instanceof FieldItemInterface && $object->getValue()) {
            $serialized_property_names = $this->getCustomSerializedPropertyNames($parent);
            if (in_array($object->getName(), $serialized_property_names, TRUE)) {
                return unserialize($object->getValue());
            }
        }
        // Typed data casts NULL objects to their empty variants, so for example
        // the empty string ('') for string type data, or 0 for integer typed data.
        // In a better world with typed data implementing algebraic data types,
        // getCastedValue would return NULL, but as typed data is not aware of real
        // optional values on the primitive level, we implement our own optional
        // value normalization here.
        return $object->getValue() === NULL ? NULL : $object->getCastedValue();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSupportedTypes(?string $format) : array {
        return [
            PrimitiveInterface::class => TRUE,
        ];
    }

}