JMS Serializer event is not working - symfony

Question

I am sure it is a small error but I cannot find it.
I am trying to follow the official doc and implement an event listener on the pre_serialize event.
My service declaration:
<service id="app.question_serializer_subscriber" class="AppBundle\Serializer\QuestionSerializerSubscriber">
<tag name="jms_serializer.event_subscriber"/>
</service>
My subscriber:
<?php
namespace AppBundle\Serializer;
use JMS\Serializer\EventDispatcher\EventSubscriberInterface;
use JMS\Serializer\EventDispatcher\ObjectEvent;
class QuestionSerializerSubscriber implements EventSubscriberInterface
{
public static function getSubscribedEvents()
{
return array(
array(
'event' => 'serializer.pre_serialize',
'method' => 'onPreSerialize',
)
);
}
public function onPreSerialize(ObjectEvent $event)
{
die('in event');
}
}
And my controller:
$question = $repo->findLastVersionByQuestionId((int) $questionId);
$serializer = SerializerBuilder::create()->build();
$context = new SerializationContext();
return new JsonResponse(json_decode(
$serializer->serialize(
$question,
'json',
$context
),
true
));
When I access the route my entity Question is serialized and displayed, but why does the die('in event'); is not displayed ?
Maybe it has a relation with the fact that my object is a Doctrine entity (issue 666 or PR 677 )

Answer 1

I finally find the issue. The problem is
$serializer = SerializerBuilder::create()->build();
This does not work but this does:
$serializer = $this->get('jms_serializer');

Answer 2

Try adding the class attribute, as example:
public static function getSubscribedEvents()
{
return array(
array(
'event' => 'serializer.pre_serialize',
'class' => 'FQCN_class_name',
'method' => 'onPreSerialize',
)
);
}
Another difference regarding the doc is in the argument of the class method: you should use PreSerializeEvent instead of ObjectEvent:
So like this:
public function onPreSerialize(PreSerializeEvent $event)
{
// ...
}
Check your service is correctly load from the container as example with the console command:
php app/console debug:container --tag=jms_serializer.event_subscriber
Hope this help