CustomNormalizer.php

<?php

declare(strict_types=1);

namespace App\Bridge\Symfony\Serializer;

use App\Serializer\ModelDenormalizeInterface;
use App\Serializer\ModelNormalizerInterface;
use Symfony\Component\Serializer\Normalizer\ObjectNormalizer as SymfonyObjectNormalizer;

/**
 * Decorate Symfony object normalizer with a set of rules
 *
 * Important notes:
 *   - You will never serialise / deserialize multiple times in the same cycle
 *   - You will never use custom serialization callbacks for the same property name cross objects
 *
 * This custom normalizer will:
 *   - [normalize] remove all empty and null values from the models properties
 *   - [normalize] set callbacks based on the model (Note: if the same property name is given it will override)
 *   - [denormalize] set callbacks based on the model denormalize method (Needs to be implementing the ModelDenormalizationInterface)
 *   - [denormalize] when preparing the data a set of callbacks will also be taken in consideration
 */
class CustomNormalizer extends SymfonyObjectNormalizer
{
    public function normalize($object, $format = null, array $context = [])
    {
        if ($object instanceof ModelNormalizerInterface) {
            // can bring some conflicts
            $this->callbacks = array_merge($this->callbacks, $object->normalize());
        }

        $data = parent::normalize($object, $format, $context);

        // remove every "null" / empty value
        return array_filter($data, function ($value) {
            return null !== $value;
        });
    }
    
    public function denormalize($data, $class, $format = null, array $context = [])
    {
        if (\in_array(ModelDenormalizeInterface::class, class_implements($class), true)) {
            /** @var ModelDenormalizeInterface $object */
            $object = new $class();
            $this->callbacks = array_merge($this->callbacks, $object->denormalize());
        }

        return parent::denormalize($data, $class, $format, $context);
    }

    /**
     * Decorate the function so we can run the callbacks define
     * for denormalization / preparing the data for the setters
     *
     * This function is only invoked before denormalizing the data
     */
    public function prepareForDenormalization($data): array
    {
        $data = parent::prepareForDenormalization($data);

        foreach ($this->callbacks as $property => $callback) {
            if (isset($data[$property])) {
                $data[$property] = $callback($data[$property], $data);
            }
        }

        return $data;
    }
}