[✅ SOLVED] Subject:

rememberUpdateState

I’ve seen most of the

@Composables

are using

rememberUpdateState

before invoking a lambda. For eg,

BackHandler

internally calling

rememberUpdateState

on

onBack

lambda,

clickable

modifier calls on

onClick

lambda. Does that mean we should wrap all lambda with

rememberUpdateState

before invoking ? 🤔 If that’s the case, why can’t compiler do it for us? #possibly_a_stupid_question

Have you checked the doc? I think it explains when you need to use

rememberUpdatedState

quite clearly.

@Albert Chang Yes. I already read that doc. That explains one of the usecases of

rememberUpdateState

with

LaunchedEffect

. But what am asking is, basically we use

rememberUpdateState

to get the latest value (or to avoid stale value). Is there a scenario where we need to access the stale value? 🤔

The point is whether there is a long-living lambda (or function) that captures the value. If there isn't such a lambda, there is no need to use

rememberUpdatedState

.

Hmm. but Lambdas are mostly long-living functions or mostly used at later time (or after the composition). For example,

onClick

,

onBack

etc. So lambas without

rememberUpdatedState

should be very rare?

No, most lambdas are not long-living. In a composable function, if the dependencies of a lambda (i.e. the variables it captures) change, a new lambda instance will be created.

okay, so basically, I only need to use

rememberUpdatedState

if and only if am accessing a lambda in an area where recomposition can’t be reached. For example,

remember

,

LaunchedEffect

, etc.. is that what you’re saying ?

Yep. But for

remember

, it's better to just use it as a key.

ahaa.. got it.

Yeah

OnBackPressedDispatcher

is designed that way.

Got it. thank you so much for bearing with me 😄

See also related DX feature request: https://issuetracker.google.com/issues/217570480