Decompose 1.0.0-alpha-01 is released! - Version u...

# decompose

[Arkadii Ivanov]

Decompose 1.0.0-alpha-01 is released!

- Version updated: Kotlin 1.7.0, Gradle 7.4.2, JB Compose 1.2.0-alpha01-dev753, Jetpack Compose 1.2.0
- Replaced BackPressedHandler with BackHandler
- Added otherChild argument to stackAnimation selector function
- Removed previously deprecated Router

And more! Release notes: https://github.com/arkivanov/Decompose/releases/tag/1.0.0-alpha-01

[xxfast]

With the Router<C,V> gone, does it mean we have to write our own one in order to do our own decompose navigator?

[Arkadii Ivanov]

Thanks for pointing it out. I think the approach should be changed as well. Something like fun rememberNavigation(): StackNavigation and fun rememberChildStack(navigation, ...): Value<ChildStack> or you can define your own Router interface around these two. I will update articles, filed https://github.com/arkivanov/Decompose/issues/173

[Arkadii Ivanov]

But you definitely don't have to write your own Router. The Router had one method navigate and state property. It is now split by StackNavigation and just Value<ChildStack>

[Laurence Muller]

The migration examples were helpful as well as the notes in:
https://github.com/arkivanov/Decompose/blob/master/decompose/src/commonMain/kotlin/com/arkivanov/decompose/router/stack/StackNavigatorExt.kt

(especially since i had to replace my bottom tab nav workaround -> https://github.com/badoo/Decompose/discussions/178#discussioncomment-1005820)

[xxfast]

Hi all - finally got around to this (after 3 months) but I'm quite confused as to how to connect these two pieces together 🤔

@Composable
fun <C: Parcelable> rememberNavigator(): StackNavigation<C> = remember { StackNavigation() }

@Composable
fun <C: Parcelable> rememberChildStack(root: C): ChildStack<C, Unit> = remember { ChildStack(root, Unit) }

My intended use site looks like this

@OptIn(ExperimentalDecomposeApi::class)
@Composable
fun RootView() {
  val childStack: ChildStack<RootNavigationPage, Unit> = rememberChildStack(Search)
  val navigator: StackNavigation<RootNavigationPage> = rememberNavigator()

  Children(
    stack = childStack
  ) { (state) ->
    when (state) {
      Search -> SearchRootView()
      Settings -> SettingsView()
      else -> {}
    }
  }
}

[Arkadii Ivanov]

Why do you need to remember ChildStack? It should be observable I guess, e.g. it should be Value or State

[Arkadii Ivanov]

I have update the article, I think it should be useful for your case - https://medium.com/proandroiddev/a-comprehensive-hundred-line-navigation-for-jetpack-desktop-compose-5b723c4f256e

[xxfast]

Nice 👍 thanks @Arkadii Ivanov. This helps me out a lot. Got a couple more questions. Is there a way to expose the current active configuration from the navigator? With previous router API i was able to do

routerState.activeChild.configuration

[xxfast]

Also - with the new API, it looks like it no longer retains state between transitions 🤔 Not sure If i implemented this wrong. Let me verify if this is the case with compose navigator example

decompose-1.0.0-beta01.mp4decompose-0.6.0.mp4

[xxfast]

Hmm the example does seem to work as intended - i definitely stuffed-up somewhere 😅

decompose-1.0.0-beta01-2.mp4

[Arkadii Ivanov]

ComonentConext#childStack function returns Value<ChildStack>, which provides you access to the state.

[Arkadii Ivanov]

You can check the sample code here - https://github.com/arkivanov/ComposeNavigatorExample/blob/d786d92632fe22e4d7874645[…]in/com/arkivanov/composenavigatorexample/navigator/Navigator.kt

[xxfast]

ah looks like my bottom nav usecase calls for something like navigateSingleTop rather than bringToFront 🤔 Looks like this was already discussed in the past but the links in the discussion seems broken - but tracing back to this issue, i'm assuming this is not kept in the library due to enum support?

[Arkadii Ivanov]

bringToFront is just another name for navigateSingleTop. The latter naming was just suggested in that discussion, but the actual API got the former naming.

[xxfast]

We should be able to use a StackNavigator for a bottom navigation use case with bringToFront, right?

[xxfast]

Turns out changing my configuration type from enum to a sealed interface seems to make bringToFront behave correctly. Not 100% sure why

bottom-nac.mp4

[xxfast]

Anyways its now fixed 🙌 Thanks @Arkadii Ivanov

[Arkadii Ivanov]

Yes, bringToFront should be usable in bottom navigation.

Also enums as configurations shouldn't be used. Basically they won't even compile for Android, but I guess you don't support Android. bringToFront removes all configurations with of the specified configuration class, and adds a new configuration at the top of the stack - see the docs. Since enum entries share the same class, the stack is cleared on every navigation.