How to recompute collections in onFlush event?

[wtorsi]

Hi,
How to recompute changes made for association in onFlush event?
At this moment, i see only one possible solution is to call computeChangeSet on changed parent entity.
But this solution will break when for example parent entity has STATE_NEW, all initial changes will be overwritten.
Documented recomputeSingleEntityChangeSet skips complex associations.

[SenseException]

Can you please describe your use case in form of code and your complex associations? It sounds like you're having a use case that onFlush isn't capable of. Maybe this is a limit of this event that needs to be written in the documentation or maybe there's a bug. Or you'll get an answer for your question.

[wtorsi]

Sure, here is the code which made changes to collection. I'm awaiting clearing collection cache in commit UOW phase.

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

    foreach ($uow->getScheduledEntityUpdates() as $entity) {
        if ($entity instanceof Category) {
            /** @var Collection $children */
            $children = $entity->getChildren();
            $child = new Child('test child');
            $children->add($child);
            $em->persist($child);
            $uow->computeChangeSet($child);

            // this will not recompute `children` collection
            $meta = $em->getClassMetadata(Category::class);
            $uow->recomputeSingleEntityChangeSet($meta, $entity);
        }
    }
}

recomputeSingleEntityChangeSet skips collection values by this part of code

    foreach ($class->reflFields as $name => $refProp) {
        if (( ! $class->isIdentifier($name) || ! $class->isIdGeneratorIdentity())
            && ($name !== $class->versionField)
            && ! $class->isCollectionValuedAssociation($name)) {
            $actualData[$name] = $refProp->getValue($entity);
        }
    }

so, only manual clearing is supported.

[SenseException]

I have to take a look and run your example code on a current version. It looks like it follows the description mentioned in the docs https://www.doctrine-project.org/projects/doctrine-orm/en/2.6/reference/events.html#onflush.

[SenseException]

@wtorsi I'm able to make one of my example work, but this can be because I miss something that results in this mentioned break in your project.

Can you please create a PR with a failing test to make this reproducible?