I’m collecting from a flow like so, as recommended...

# coroutines

[Alexander Maryanovsky]

I’m collecting from a flow like so, as recommended:

lifecycleScope.launch{
    lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED){
        flow.collect{
            ...
        }
    }
}

I would like the collection, and the entire coroutine to stop when the flow completes. But repeatOnLifecycle never returns, even after collect returns, and if the activity is stopped and restarted, collection is launched again.
It seems I need runOnceOnLifecycle.

[Alexander Maryanovsky]

Cancelling the outer scope when flow.collect returns seems to do the trick.

[Alexander Maryanovsky]

suspend fun Lifecycle.runOnceOnLifecycle(
    state: Lifecycle.State,
    block: suspend CoroutineScope.() -> Unit
){
    coroutineScope {
        repeatOnLifecycle(state) {
            block()
            [e-mail]()
        }
    }
}

[yschimke]

I think whenStarted does what you want https://developer.android.com/topic/libraries/architecture/coroutines#suspend

[Alexander Maryanovsky]

If I understand correctly, whenStarted is not the same. repeatOnLifecycle(STARTED) will cancel the coroutine running the block when the state is below started and start it again when the state is again started.
whenStarted, on the other hand, will merely suspend the block.

[Alexander Maryanovsky]

If block is collecting a flow, this will result in different behavior upstream.

[myanmarking]

Idk if there is any official way, but you can use a flag: .oncompleted {flag = true }