According to http://www.doctrine-project.org/docs/orm/2.1/en/reference/events.html
Current event system seem to be not as flexible as it could be.
1. According Lifecycle Events of the entity (marked with @HasLifecycleCallbacks annotation tag):
It would be useful to have access to Entity Manager inside the callbacks. This could be achieved by passing the entity manager as a parameter to all these callbacks.
Here is the situation:
I have an entity for a news item. After somehow modifying this entity and before persisting I want to be able to change the inner association of images linked to this news (for example parsed from news body text). From the OO point of view it's a task of the News entity itself so this should be done a callback. But since inside callback I do not have access to entity manager (to find existing image entities and only if not found creating a new one) I cannot do this.
This leads to creating a separate event listener which is split from the news entity (and that is not possible, see 2.).
Passing entity manager to callbacks may improve it's usefulness.
2. Currently there is no events to be called before the changes have been computed. And there is no callback to be called after flush has been finished. (preFlush, postFlush)
Assume we have a News entity. I want to modify external system (even not written in PHP) via remote call after any change to news being made. This has to be called AFTER the flush has persisted all the changes. Currently the only place to do this is onFlush (which is called before the persisting is done).
PostPersist, postRemove, postUpdate cannot be used as it's called after each one entity is modified and we cannot tell when all entites has been processed.
Also I faced a problem when implementing the event listener for situation 1. If I register the onFlush listener - the entites changeset is already calculated. If I change something according associations I loose this changes.
If I call $unitOfWork->computeChangeSet($classMetadata, $entity) or $unitOfWork->recomputeSingleEntityChangeSet($classMetadata, $entity); I only get the changes being made after previous changeset calculation loosing the initial changes. I think the preFlush could be a lifesaver for this (to be called before computing the changeset for the first time).