May 24, 2019 · May 18, 2019
diff --git a/components/serializer.rst b/components/serializer.rst
 Using Callbacks to Serialize Properties with Object Instances
 -------------------------------------------------------------

 .. deprecated:: 4.2

    The :method:`Symfony\\Component\\Serializer\\Normalizer\\AbstractNormalizer::setCallbacks`
    method is deprecated since Symfony 4.2. Use the ``callbacks``
    key of the context instead.

 When serializing, you can set a callback to format a specific object property::

    use App\Model\Person;
    use Symfony\Component\Serializer\Serializer;

    $encoder = new JsonEncoder();
    $normalizer = new GetSetMethodNormalizer();

    // all callback parameters are optional (you can omit the ones you don't use)
    $callback = function ($innerObject, $outerObject, string $attributeName, string $format = null, array $context = []) {
        return $innerObject instanceof \DateTime ? $innerObject->format(\DateTime::ISO8601) : '';
    };

    $normalizer->setCallbacks(['createdAt' => $callback]);
    $defaultContext = [
        AbstractNormalizer::CALLBACKS => [
            'createdAt' => $callback,
        ],
    ];

    $normalizer = new GetSetMethodNormalizer(null, null, null, null, null, $defaultContext);

    $serializer = new Serializer([$normalizer], [$encoder]);
Original file line number	Diff line number	Diff line change
Expand Up		@@ -623,6 +623,12 @@ and ``remove``.
		Using Callbacks to Serialize Properties with Object Instances
		-------------------------------------------------------------

		.. deprecated:: 4.2

		The :method:`Symfony\\Component\\Serializer\\Normalizer\\AbstractNormalizer::setCallbacks`
		method is deprecated since Symfony 4.2. Use the ``callbacks``
		key of the context instead.

		When serializing, you can set a callback to format a specific object property::

		use App\Model\Person;
Expand All		@@ -631,14 +637,19 @@ When serializing, you can set a callback to format a specific object property::
		use Symfony\Component\Serializer\Serializer;

		$encoder = new JsonEncoder();
		$normalizer = new GetSetMethodNormalizer();

		// all callback parameters are optional (you can omit the ones you don't use)
		$callback = function ($innerObject, $outerObject, string $attributeName, string $format = null, array $context = []) {
		return $innerObject instanceof \DateTime ? $innerObject->format(\DateTime::ISO8601) : '';
		};

		$normalizer->setCallbacks(['createdAt' => $callback]);
		$defaultContext = [
		AbstractNormalizer::CALLBACKS => [
		'createdAt' => $callback,
		],
		];

		$normalizer = new GetSetMethodNormalizer(null, null, null, null, null, $defaultContext);

		$serializer = new Serializer([$normalizer], [$encoder]);

Expand Down