next problem :see_no_evil:, I'm deriving another t...

# rx

[iex]

next problem 🙈, I'm deriving another thing from `dealerAction`:

private val dealerButtonTrigger: PublishSubject<Unit> = PublishSubject.create()

init {
    dealerButtonTrigger.withLatestFrom(dealerAction.toObservable())
        .subscribe { (_, action) ->
            action.handle()
        }
}

Here, when I click (i.e. call dealerButtonTrigger.onNext(Unit)) after updating the dealer and navigating back, it still gives me the first dealer. Shouldn't it get the updated value?

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

This is exactly why I was asking this question in the previous thread: https://kotlinlang.slack.com/archives/C0B8Y8BHC/p1582647883026000?thread_ts=1582644781.011600&cid=C0B8Y8BHC

dealerAction is a Single – it only emits a single value. It doesn’t have the concept of “updated value”. If the value can change over time, it should be an Observable, and the object backing dealerAction should have some way of signaling that the value changed.

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

Calling toObservable() just changes the type, it doesn’t magically add logic that knows how to detect when your data sources changes.

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

You actually already answered your own question here in the other thread 😉

https://kotlinlang.slack.com/archives/C0B8Y8BHC/p1582647493025000?thread_ts=1582644781.011600&cid=C0B8Y8BHC

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

To get the “updated value” behavior you’re expecting, that’s what you’d need to do.

[iex]

right! I get it now. That's also why it doesn't work out of the box (without toObservable() )

[iex]

well, not necessarily. It still makes sense.

[iex]

just not for my use case 😅