docrtine 2 versioning associations

Question

I need to implement versioning for some entities.

I have an entity "Map" which has a OneToMany association with "Spot" Entities. The "Map" and also "Spot" should be versionable.

It should be possibler to show older versions of a "Map" with all the asociated "Spots" on it.

So on an old version the "Map" itself could have another backgound-image, but also the position or number of associated "Spots" can differ.

I like this approach of the AuditLog (at the end of the page): http://www.doctrine-project.org/blog/doctrine2-versionable.html

[php]
class AuditListener implements EventSubscriber
{
    public function getSubscribedEvents()
    {
        return array(Events::onFlush);
    }

    public function onFlush(OnFlushEventArgs $args)
    {
        $em = $args->getEntityManager();
        $uow = $em->getUnitOfWork();

        $changeDate = new DateTime("now");
        $class = $em->getClassMetadata('DoctrineExtensions\Auditable\AuditEntry');

        foreach ($uow->getScheduledEntityUpdates() AS $entity) {
            if ($entity instanceof Auditable) {
                $changeSet = $uow->getEntityChangeSet($entity);

                foreach ($changeSet AS $field => $vals) {
                    list($oldValue, $newValue) = $vals;
                    $audit = new AuditEntry(
                        $entity->getResourceName(),
                        $entity->getId(),
                        $oldValue,
                        $newValue,
                        $changeDate
                    );

                    $em->persist($audit);
                    $em->getUnitOfWork()
                       ->computeChangeSet($class, $audit);
                }
            }
        }
    }
}

I wonder how to handle association of the versionable entity.

For Example:

When a "Map" changes, a new Map Version is saved, but what about the Association to the Spots? When a "Spot" changes, what about its parent "Map".

When buliding the new Version of "Map": - how can I figure out that it has Association? - how can I figure out that a Association is also Versionable - how do I handle the Associatons

Even if an association is not versionable, if I change an associated non-versionable entity I also change the old versions of "Map" because they are also still associated.

Does anyone has experience or ideas how to manage that with doctrine 2.1?