How to launch a coroutine that should never be canceled from a Compose event handler

Question

I have this composable that represents an "edit data" screen:

@Composable
fun EditNodeScreen(
    vm: EditNodeViewModel,
    canceled: () -> Unit,
    accepted: (id: UUID) -> Unit
) {
    // ...
    Button(onClick = {
      val id = vm.save()
      accepted(id)
    }) {
      Text(text = "Save")
    }
}

Except, EditNodeViewModel.save() is actually a suspend function, so I can't just call it like that.

What I can find says that I should create a coroutine scope with rememberCoroutineScope() , then use that to launch a coroutine:

onClick = {
    coroutineScope.launch {
        val id = vm.save()
        accepted(id) // side question: do I have to switch back to Main context?
    }
}

But the documentation also says that this coroutine will be canceled if the composition is detached. I do not want to cancel the save process once it is commenced!

Is this still the right thing to do, or is there a better way? Should I use GlobalScope.launch perhaps?

Answer 1

If you have to handle an operation that should be completed even if the user navigates away from the screen, use WorkManager .

From the Docs ,

WorkManager is intended for work that is required to run reliably even if the user navigates off a screen, the app exits, or the device restarts.

Use Expedited work to start the task immediately.