Is passing mutablestate to composable function optimal?

Question

Like this :

@Composable
fun TextEdit(textState: MutableState<String>) {
    val text by textState
    TextField(onValueChange = {
        text = it
    }, value = text)
}

Is it optimal for unnecessary recompositions?

Answer 1

That will still trigger unnecessary recompositions, instead try using the concept of state hoisting where your code should be:

@Composable
fun TextEdit(textState: String) {
    
    TextField(onValueChange = {
        textState = it
    }, value = textState)
}

Here is the Best Practice to follow:

You should hoist UI state to the lowest common ancestor between all the composables that read and write it. You should keep state closest to where it is consumed. From the state owner, expose to consumers immutable state and events to modify the state.

The lowest common ancestor can also be outside of the Composition. For example, when hoisting state in a ViewModel because business logic is involved.