Question: I am attempting to use a custom handler for JMS Serializer Bundle

```
class CustomHandler implements SubscribingHandlerInterface
{
    public static function getSubscribingMethods()
    {
        return array(
            array(
                'direction' => GraphNavigator::DIRECTION_SERIALIZATION,
                'format' => 'json',
                'type' => 'integer',
                'method' => 'serializeIntToJson',
            ),
        );
    }

    public function serializeIntToJson(JsonSerializationVisitor $visitor, $int, array $type, Context $context)
    {
         die("GIVE ME SOMETHING");
    }
}

```

This does nothing, and does not die. This is how I am registering the handler

```
$serializer = SerializerBuilder::create()
    ->configureHandlers(function(HandlerRegistry $registry) {
        $registry->registerSubscribingHandler(new MyHandler());
    })
    ->addDefaultHandlers()
    ->build();

$json = $serializer->serialize($obj, 'json');

```

My handler is never called and I cannot manipulate the data on serialisation.

Answer: 
You need to create a service for this handler:

```
custom_jms_handler:
    class: MyBundle\Serializer\CustomHandler
    tags:
        - { name: jms_serializer.subscribing_handler }

```

Then make sure you use the registered JMS serializer service

```
$json = $this->get('jms_serializer')->serialize($obj, 'json');

```
I have this which works

```
    $serializer = SerializerBuilder::create()
        ->configureListeners(function(EventDispatcher $dispatcher) {
            $dispatcher->addSubscriber(new ProjectSubscriber($this->container));
            $dispatcher->addSubscriber(new UserSubscriber($this->container));
        })
        ->addDefaultListeners()
        ->addMetadataDir(realpath($this->get('kernel')->getRootDir()."/../") . '/src/Jake/NameOfBundle/Resources/config/serializer')
        ->build();

    return $serializer->serialize($project, 'json');

```

`$project` is my entity.

You can omit this line if you don't have serializer configs

```
->addMetadataDir(realpath($this->get('kernel')->getRootDir()."/../") . '/src/Jake/NameOfBundle/Resources/config/serializer')

```

I think my main issue was this `->addDefaultListeners()`.

In `config.yml` I have

```
jms_serializer:
    metadata:
        auto_detection: true
        directories:
            NameOfBundle:
                namespace_prefix: ""
                path: "@JakeNameOfBundle/Resources/config/serializer"

```

I don't have anthing set up to make JMS a service.