Is is possible detect when the scope is canceled i...

# coroutines

[Pablo]

Is is possible detect when the scope is canceled in a flow .onCompletion ?
I have this flow :

flow {
  for(foo in bar downTo 0){
    emit(foo)
    delay(1_000L)
  }
}

Then I consume it :

myFlow()
 .onEach {
    updateUI
  }
 .onCompletion {
   //Do something but only when the timer is 0 not when cancelled
 }
 .launchIn(scope)

In some point I do cancel the scope and it automatically get into `onCompletion` so even if the timer is not over yet, it does the thing of timer finished because I have the code there, is there any way I can get if the completion is because ok the for loop or for a cancellation of scope?

[stojan]

in onCompletion you have access to the Throwable (if canceled) or null otherwise:

flow.onCompletion { if (it == null) println("Completed successfully") }

[Pablo]

I've also tried

if(currentCoroutineContext().isActive) completed

But is there any generic way so I don't update every onCompletion{} of my project?

[Paul Woitaschek]

Write an extension function

[Paul Woitaschek]

Sth like:

public fun <T> Flow<T>.onCompletionIfNotCancelled(
  action: suspend FlowCollector<T>.() -> Unit
): Flow<T> {
  return onCompletion {
    if (it !is CancellationException) {
      action()
    }
  }
}