What's the recommended way to collect broadcast re...

# compose-android

[André Thiele]

What's the recommended way to collect broadcast receiver events in Compose? produceState with awaitDispose to unregister receiver?

[Chrimaeon]

Please do not cross-post to multiple channels with already ongoing discussion;

https://kotlinlang.slack.com/archives/CJLTWPH7S/p1772360879279979

[André Thiele]

i moved the thread here because it was wrong channel before, damn this slack is pissing me off already

[Mark Murphy]

My gut instinct is to receive the broadcasts anywhere other than a composable. What specific broadcast do you have in mind, and why is the UI layer involved?

[Chrimaeon]

well you did not “move” it, you copy/pasted it 😉

[André Thiele]

you responded to old thread too

[André Thiele]

well

[André Thiele]

anyways, here's what i had in mind:

class SystemTimeZoneObserver : TimeZoneObserver {
@Composable
override fun rememberTimeZone(): TimeZone {
val context = LocalContext.current
return produceState(initialValue = TimeZone.currentSystemDefault()) {
val receiver =
object : BroadcastReceiver() {
override fun onReceive(ctx: Context?, intent: Intent?) {
value = TimeZone.currentSystemDefault()
}
}
val filter = IntentFilter(Intent.ACTION_TIMEZONE_CHANGED)
filter.addAction(Intent.ACTION_TIME_CHANGED)
filter.addAction(Intent.ACTION_DATE_CHANGED)
context.registerReceiver(receiver, filter)

awaitDispose { context.unregisterReceiver(receiver) }
}
.value
}
}

thought of using it in presenters, however putting it in repos and collecting flow as state is probably better.

[Jonathan]

I'd recommend using a callbackFlow to "convert" the broadcast receiver into a Flow and then use collectAsStateWithLifecycle(initialValue = SOMETHING) to collect from it in Compose. I recommend declaring the callbackFlow in a VM or a repo so that it doesn't get recreated if/when your screen leaves composition.