Serialize Persistent colletions with JMS serialize - doctrine-orm

Question

I have been using the "jms/serializer": "0.13.*#dev" in order to serialize my objects.
I am using it in a Zend Framework (2) and a Doctrine project.
This is my code:
use JMS\Serializer\SerializerBuilder as SerializerBuilder;
(....)
public function getList() {
$em = $this->getEntityManager();
$repo = $em->getRepository('MyApp\Entity\Product');
$hydrator = new DoctrineHydrator($em);
$data = array();
foreach ($repo->findAll() as $found) {
$data[] = $hydrator->extract($found);
}
$serializer = SerializerBuilder::create()->build();
$jsonContent = $serializer->serialize($data, 'json');
$this->getResponseWithHeader()->setStatusCode(self::OK_200);
return new JsonModel($jsonContent);
}
But I am getting this error:
Resources are not supported in serialized data. Path: MyApp\Entity\FOO -> Doctrine\ORM\PersistentCollection -> MyApp\Entity\Product -> Doctrine\ORM\PersistentCollection -> DoctrineORMModule\Proxy__CG__\MyApp\MyApp\Brand
Apparently you can't serialize persistent collections.
I have googled around and found this Symfony related question. But how can I solve this problem within the stand alone Serializer library?
Thanks very much.
EDIT
Can this have anything to do with JMS annotations? Should I use certain annotations to get this working?

Answer 1

I'm guessing the issue here is that the PersistentCollection may contain a reference to a database connection so JMS can't handle the Resource type.
If you only want the first level serialised then I guess you could hack at it like:
foreach ($repo->findAll() as $found) {
// Set these to basically empty arrays
$found->setRelation1(new \Doctrine\Common\Collections\ArrayCollection);
$found->setRelation2(new \Doctrine\Common\Collections\ArrayCollection);
$data[] = $hydrator->extract($found);
}
Or you could extend the JMS Serialize function to just ignore Resource collections rather than throwing an Exception.