Doctrine 3 merge alternantive - php

Question

I am currently using doctrine merge to "restore" an entity with relationships after retrieving it from the session.
As from doctrine 3, this function will be deprecated so I am wondering if there is any way to keep an entity object in the session for a while before persisting it to the database.
I need this for a multistep form through which my object gets populated.
For now, the only solution i see is storing the entity in a temporary database table but i don't really like this idea because my table will be filled with "junk".
Thanks !

Answer 1

There are two ways that I have found.
The first is to create your own implementation. I have go this way because there were a lot of usages of merge in project. It looks hacky, but works:
class DoctrineMergeService
{
/**
* #var EntityManager
*/
private $em;
/**
* #param EntityManager $em
*/
public function __construct(EntityManager $em)
{
$this->em = $em;
}
/**
* #param object $entity
*
* #return object
*
* #throws \Doctrine\ORM\ORMException
* #throws \Doctrine\ORM\OptimisticLockException
* #throws \Doctrine\ORM\TransactionRequiredException
*/
public function merge(object $entity): object
{
$mergedEntity = null;
$className = get_class($entity);
$identifiers = $this->getIdentifiersFromEntity($entity);
$entityFromDoctrine = $this->em->find($className, $identifiers);
if ($entityFromDoctrine) {
$mergedEntity = $this->mergeEntities($entityFromDoctrine, $entity);
} else {
$this->em->persist($entity);
$mergedEntity = $entity;
}
return $mergedEntity;
}
/**
* #param object $entity
*
* #return array
*/
private function getIdentifiersFromEntity(object $entity): array
{
$className = get_class($entity);
$meta = $this->em->getClassMetadata($className);
$identifiers = $meta->getIdentifierValues($entity);
return $identifiers;
}
/**
* #param object $first
* #param object $second
*
* #return object
*/
private function mergeEntities(object $first, object $second): object
{
$classNameFirst = get_class($first);
$metaFirst = $this->em->getClassMetadata($classNameFirst);
$classNameSecond = get_class($second);
$metaSecond = $this->em->getClassMetadata($classNameSecond);
$fieldNames = $metaFirst->getFieldNames();
foreach ($fieldNames as $fieldName) {
$secondValue = $metaSecond->getFieldValue($second, $fieldName);
$metaFirst->setFieldValue($first, $fieldName, $secondValue);
}
return $first;
}
}
The second is to use serializer, not tested:
// this is controller or something like controller
public function save($id)
{
$serializedJsonFromSession = $this->session->get('serialized_json');
$doctrine = $this->getDoctrine();
$entity = $doctrine->getRepository(Entity::class)->find($id);
if (!$entity) {
$entity = new Entity();
$doctrine->persist($entity);
}
$serializer->deserialize(
$serializedJsonFromSession,
Entity::class,
'json',
[AbstractNormalizer::OBJECT_TO_POPULATE => $entity]
);
$doctrine->flush();
}