Activating the Serializer¶

The serializer service is not available by default. To turn it on, activate it in your configuration:

Using the Serializer Service¶

Once enabled, the serializer service can be injected in any service where you need it or it can be used in a controller:

// src/AppBundle/Controller/DefaultController.php
namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\Serializer\SerializerInterface;

class DefaultController extends Controller
{
    public function indexAction(SerializerInterface $serializer)
    {
        // keep reading for usage examples
    }
}

Adding Normalizers and Encoders¶

Once enabled, the serializer service will be available in the container. It comes with a set of useful encoders and normalizers.

Encoders supporting the following formats are enabled:

• JSON: Symfony\Component\Serializer\Encoder\JsonEncoder
• XML: Symfony\Component\Serializer\Encoder\XmlEncoder

As well as the following normalizers:

• Symfony\Component\Serializer\Normalizer\ObjectNormalizer to handle typical data objects
• Symfony\Component\Serializer\Normalizer\DateTimeNormalizer for objects implementing the DateTimeInterface interface
• Symfony\Component\Serializer\Normalizer\DataUriNormalizer to transform SplFileInfo objects in Data URIs
• Symfony\Component\Serializer\Normalizer\JsonSerializableNormalizer to deal with objects implementing the JsonSerializable interface
• Symfony\Component\Serializer\Normalizer\ArrayDenormalizer to denormalize arrays of objects using a format like MyObject[] (note the [] suffix)

Custom normalizers and/or encoders can also be loaded by tagging them as serializer.normalizer and serializer.encoder. It’s also possible to set the priority of the tag in order to decide the matching order.

Here is an example on how to load the Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer, a faster alternative to the ObjectNormalizer when data objects always use getters and setters:

Using Serialization Groups Annotations¶

Enable serialization groups annotation with the following configuration:

Next, add the @Groups annotations to your class and choose which groups to use when serializing:

$json = $serializer->serialize(
    $someObject,
    'json', array('groups' => array('group1'))
);

In addition to the @Groups annotation, the Serializer component also supports Yaml or XML files. These files are automatically loaded when being stored in one of the following locations:

• The serialization.yml or serialization.xml file in the Resources/config/ directory of a bundle;
• All *.yml and *.xml files in the Resources/config/serialization/ directory of a bundle.

Enabling the Metadata Cache¶

Metadata used by the Serializer component such as groups can be cached to enhance application performance. Any service implementing the Doctrine\Common\Cache\Cache interface can be used.

A service leveraging APCu (and APC for PHP < 5.5) is built-in.

Enabling a Name Converter¶

The use of a name converter service can be defined in the configuration using the name_converter option.

The built-in CamelCase to snake_case name converter can be enabled by using the serializer.name_converter.camel_case_to_snake_case value:

Going Further with the Serializer¶

ApiPlatform provides an API system supporting JSON-LD and Hydra Core Vocabulary hypermedia formats. It is built on top of the Symfony Framework and its Serializer component. It provides custom normalizers and a custom encoder, custom metadata and a caching system.

If you want to leverage the full power of the Symfony Serializer component, take a look at how this bundle works.