Is there any way to get an entity ID before the persist/flush? I mean:
$entity = new PointData();
$form = $this->createForm(new PointDataType(), $entity);
If I try $entity->getId() at this point, it returns nothing.
I can get it working by:
$em->persist($entity);
$em->flush();
(supposing $em = $this->getDoctrine()->getEntityManager();)
How can I achieve this?
If you want to know the ID of an entity before it's been persisted to the database, then you obviously can't use generated identifiers. You'll need to find some way to generate unique identifiers yourself (perhaps some kind of hash function can produce unique-enough values).
This is rarely a good idea, though, so you should be careful.
I would think very carefully about why I need to know the identifier before flush. Doctrine is quite good at letting you build up a big object graph, and persist/flush it all at once. It seems likely that you've got something ugly in your architecture that you're trying to work around. It might be a good idea to review that before going down the application-generated-id route.