A way to delay a callback until after the current transaction has committed successfully

[diesieben07]

It would be useful to have a way to delay code until after the current transaction is committed. The use-case for this are external effects that happen as a result of an "after change" hook or similar. I am currently adding push notifications to a backend using Payload, which should be sent whenever there is a new document in a specific collection. If I send out the notification in an "after change" hook, but then transaction rolls back, I have just sent out a notification for something that doesn't actually exist.

Prior Art

• Django has transaction.on_commit
• Spring has TransactionalEventListener
• Laravel/Eloquent ORM has DB::afterCommit (I couldn't find the docs about this, but here is a blog post: https://divinglaravel.com/better-management-of-database-transactions-in-laravel-8)

The way this could be implemented is to store an array transactionCallbacks in PayloadRequest and have commitTransaction execute them after committing.

[ssyberg]

Great timing, was also looking for similar behavior today. Another use case is where a side effect requires the mongo data to be written and available. In my particular use case I have a side effect that needs to be run after create but keeps failing because the record doesn't exist yet (I've hacked this by explicitly committing the transaction early, but that is brittle and defeats the purpose of the transaction).