What is the best approach, if you want to check va...

# compose

[Peter]

What is the best approach, if you want to check value from the previous recomposition?

For example:

fun Pin(pin: String) {
    val previousPin: String = TODO()
    val isDeleting = pin.length < previousPin.length
}

[jw]

That's what remember is for! Just make sure you don't use a key to ensure it's only remembered positionally in the composition. You probably want to use a SideEffect to write the new value to ensure only completed recompositions update it.

[Peter]

That was my initial idea yeah, thanks. I'm wondering if there is something better around.

val lastPin = remember { mutableStateOf(pin) }

val isDeleting = lastPin.value.length > pin.length

LaunchedEffect(pin) {
    lastPin.value = pin
}

[shikasd]

You don't want to use mutableStateOf here, it triggers an additional recomposition. Consider using some wrapper with a singular var field

class Ref<T>(var value: T)

val lastPin = remember { Ref(pin) }
SideEffect {
  lastPin.value = pin
}