Is the SideEffect

deriveStateOf

not able to work together with

snapshotFlow

in aiding recomposition? Separate them out seems working, but not together. The code example in https://stackoverflow.com/q/70771821/3286489

Hm, that’s really weird. Will try to repro in a bit

Thanks. The more I try, the more I feel it’s a bug. But I cannot confirm so.

I can reproduce, and it is super weird… Here’s a more minimized version:

var count by remember { mutableStateOf(0) }
    var fromSnapshot by remember { mutableStateOf(false) }
    val fromDerived by remember { derivedStateOf { count > 0 } }

    LaunchedEffect(Unit) {
        snapshotFlow { count }.collect { fromSnapshot = it > 1 }
    }

    Column {
        Text("Button clicked at least 1 time: $fromDerived")
        Text("Button clicked at least 2 times: $fromSnapshot")
        Button(onClick = { count++ }) {
            Text("Increase count")
        }
    }

fromSnapshot

will be set to

true

when the button is clicked twice, but the text won’t be updated to reflect that.

What version of Compose are you using? If you are using 1.0, can you try 1.1 RC?

A bug report is file at https://issuetracker.google.com/issues/215402574. I’m using 1.0.5