Callback on serializer Symfony

Question

I\'m running Symfony 2.7 and I\'m trying output an object (Doctrine entity) as JSON.

When I\'m normalizing the object I want to convert some of it\'s values. To do t

Answer 1

The default Serializer service is created during dependency injection phase, and the Serializer interface do not allow editing of (full) retrieval of normalizers.

I think you have (at least) three choice here:

1. add your custom normalizer to the default Serializer service
2. add NormalizableInterface to your entities
3. create a new Serializer service (or a local object as suggested by the docs) as you were trying to do.

I think in your scenario, case 1 is preferred (since 2 becomes boring pretty fast).

I would do something like this; first create a custom Normalizer

format(\DateTime::ISO8601);
    }

    /**
     * {@inheritdoc}
     */
    public function denormalize($data, $class, $format = null, array $context = array())
    {
        return new $class($data);
    }

    /**
     * Checks if the given class is a DateTime.
     *
     * @param mixed  $data   Data to normalize.
     * @param string $format The format being (de-)serialized from or into.
     *
     * @return bool
     */
    public function supportsNormalization($data, $format = null)
    {
        return $data instanceof \DateTime;
    }

    /**
     * Checks if the given class is a DateTime.
     *
     * @param mixed  $data   Data to denormalize from.
     * @param string $type   The class to which the data should be denormalized.
     * @param string $format The format being deserialized from.
     *
     * @return bool
     */
    public function supportsDenormalization($data, $type, $format = null)
    {
        $class = new \ReflectionClass($type);

        return $class->isSubclassOf('\DateTime');
    }
}

Then register it to your services:

# app/config/services.yml
services:
    datetime_normalizer:
        class: AppBundle\DateTimeNormalizer
        tags:
            - { name: serializer.normalizer }