I have a composable ‘screen’, that uses `LaunchedEffect` to perform one-off navigation events, based...

# compose

[Tim Malseed]

I have a composable ‘screen’, that uses LaunchedEffect to perform one-off navigation events, based on state. So, for example, if the current viewState is Unauthorized, I might use a LaunchedEffect to call navigateToLoginScreen()

But, let’s say there are two of these launched effects, with two possible navigation destinations. I’ve noticed an issue where, if the viewState updates and triggers a navigation event - the viewState can again update before that navigation transition is complete - triggering yet another navigation event. This means my navigation can end up in an unexpected state.

Is there a way to ensure a LaunchedEffect is cancelled before the composition leaves the tree (like, during a navigation transition)?

[Ben Trengrove [G]]

You can wrap your navigate calls in a check to make sure the lifecycle is still active. https://github.com/android/compose-samples/blob/081721ad44dfb29b55b1bc34f83d693b6b[…]k/app/src/main/java/com/example/jetsnack/ui/JetsnackAppState.kt

[Ian Lake]

FWIW, probably a better question for #compose-android going forward

[Ian Lake]

But yep, checking for RESUMED is enough, see the previous time we discussed this: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1677626180373409?thread_ts=1677626180.373409&cid=CJLTWPH7S

[Tim Malseed]

Ohhh I thought compose and compose-android were merged

[Ian Lake]

Just the opposite, #compose-android is the new home for Android only stuff: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1678882852468139

[Tim Malseed]

No worries, thanks 🙂

[Tim Malseed]

Thanks all. I tried this approach (only navigate if the initiating back stack entry is resumed). It solves one problem, but introduces another!

I’ve asked over at #compose-android. It feels rather complicated 😞

https://kotlinlang.slack.com/archives/C04TPPEQKEJ/p1679372439660899