Hi everyone, is there a way to get the the previously emmited value of a flow in the onEach function...

# android

[Tiago Nunes]

Hi everyone, is there a way to get the the previously emmited value of a flow in the onEach function, or something like this?

private val refreshJob = filterFlow
    .onEach { prev, new ->
        if(prev.x != new.x) {
            updateX()
        }
    }
    .launchIn(viewModelScope)

I know I can separate the filterFlow in multiple flows, which is probably the better way of solving my use case, but I'm still curious

[Zach Klippenstein (he/him) [MOD]]

scan and return the new item

[Ian Lake]

Also, you might try #coroutines for future questions around Flows

[Tiago Nunes]

@Zach Klippenstein (he/him) [MOD] I only care about the last 2 emmited values, how I implement this with scan?

[Zach Klippenstein (he/him) [MOD]]

Have you looked at the scan function? It gives you the previous and new values

[Andy Byrnes]

Judging by the contents of the forEach, is map { it.x }.distinctUntilChanged().onEach { updateX() } not sufficient?

[Tiago Nunes]

Hm I think all I need is distinctUntilChanged, it can take a (*old*: T, *new*: T) -> *Boolean* lambda

[Tiago Nunes]

Thanks @Andy Byrnes 🎉