MarkupNormalizer.php

<?php

namespace Drupal\serialization\Normalizer;

use Drupal\Component\Render\MarkupInterface;

/**
 * Normalizes MarkupInterface objects into a string.
 */
class MarkupNormalizer extends NormalizerBase {
    
    /**
     * {@inheritdoc}
     */
    public function normalize($object, $format = NULL, array $context = []) : array|string|int|float|bool|\ArrayObject|null {
        return (string) $object;
    }
    
    /**
     * {@inheritdoc}
     */
    public function hasCacheableSupportsMethod() : bool {
        @trigger_error(__METHOD__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use getSupportedTypes() instead. See https://www.drupal.org/node/3359695', E_USER_DEPRECATED);
        return TRUE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSupportedTypes(?string $format) : array {
        return [
            MarkupInterface::class => TRUE,
        ];
    }

}