在另一个实体被删除\\更新后如何删除\\更新准则2实体

Question

In my particular case I have the following:

I have an entity which at some point may be automatically removed as an orphan. Now, I need to react on its removal. Moreover, I do not know exactly if this reaction will or will not involve some doctrine operations . Particularly, I need to trigger some method on some decoupled component and I do not know this component`s implementation details. For example, my default implementation of that component makes use of Doctrine and need to remove some entity when the previously mentioned entity has been removed.

Now the problem itself:

I know that the EntityManager flush operation can not be triggered in the lifecycle events (It is mentioned in the docs, and it is because the lifecycle events occur in the flush method). Particularly it can not be triggered in the postRemove event. So, the problem is that, after some entity removal, I need to trigger some action that may (or may not) trigger doctrine entitymanager flush method but I can not do it in the postRemove event. And I do not know any other place where I can do it safely.

Answer 1

Ok, finaly I came to the following decision:

In the postRemove action I just add some action (as a simple callable) to the queue. Later on, in the postFlush event I process the queued actions (Its ok, because postFlush event happens after the flush process has been finished).

To implement this in some general way I created a very simple queue manager library ( https://github.com/numesmat/QueueManager ) and a corresponding symfony bundle to wire it up ( https://github.com/numesmat/QueueManagerBundle ).

Now, to add some postRemove logic I just need to do something like this in my event subscriber:

public function postRemove(LifecycleEventArgs $args) {
    $queueManager = $this->container->get('arko.queue_manager');
    $queueManager->add(function() {
        // Some logic that can potentially use doctrine flush here
    }, 'my_queue_name');
}

public function postFlush(PostFlushEventArgs $args) {
    $queueManager = $this->container->get('arko.queue_manager');
    $queueManager>process('my_queue_name');
}

In the next few days I gonna write readme to my small queue manager library and bundle. Right now, this library or bundle may be installed using composer ( arko/queue-manager and arko/queue-manager-bundle composer packages respectively) and used as simple as described above.