Best way to observe changes to CoreData using the ReducerProtocol and SwiftConcurrency

[JackYoung2]

Hi everyone,

I’m trying to hook up a listener to changes in CoreData in the ReducerProtocol version of TCA. I want to set a listener up on viewDidAppear, observe changes in the data model and automatically convert the NSManagedObject into a Struct, and update my app state and UI. I could accomplish this with a combine Publisher, but I’d like to know if there’s a suitable swift concurrency tool I could use instead. I’ve played around with Async stream and async iterator but have been unable to accomplish the task so far.

Here's what I’m trying to do in the reducer:

return .run { send in
                    let objects = databaseClient.exercisesFetchedResultsProvider
                    
                    for try await results in objects {
                        let res = objects.map(Exercise.init(storedExercise:))
                        await send (.storedExercisesDidChange(res))
                    }
                }
                .cancellable(id: FetchId.self, cancelInFlight: true)

And in the ExercisesFetchedResultsProvider I’m trying to graft an NSFetchedResultsController with a delegate callback onto some kind of async sequence or async iterator. Can somebody tell me the right tool for the job, or am I trying to fit a square peg into a round hole?

Thanks very much in advance