What is the reason, that the lifecycle of a child component must not be destroyed? https://arkivanov.github.io/Decompose/component/child-components/ Our use case: We have an infinite list (messenger timeline), where elements are created and removed when scrolling up and down. Each element view model uses a childContext of the timeline. We pass a lifecycle to destory it, when the element is remove from the list. Now we get

The lifecycle of a child ComponentContext must never be destroyed manually.

Decompose

3.3.0-alpha01

is released! 👉 Added the new Web Navigation API with nested navigation support 👉 Added placeholders for

ChildPanels

composable function 👉 Use

Nothing

type for

ChildPanels

composable function without Extra panel 👉 Fixed a crash when multiple retained components are created with different keys Release notes: https://github.com/arkivanov/Decompose/releases/tag/3.3.0-alpha01

@Arkadii Ivanov I am facing this weird error when navigating

Expected to be called on the main thread, but was DefaultDispatcher-worker-2
com.arkivanov.decompose.mainthread.NotOnMainThreadException: Expected to be called on the main thread, but was DefaultDispatcher-worker-2

Even though im not calling navigate from any coroutine I even tried adding this

launch(Dispatchers.Main)

intentionally, but i still get this error

private fun navigate(
    screen: ScreenConfig,
    replace: Boolean = false,
    replaceAll: Boolean = false
) = rootComponent.scope.launch(Dispatchers.Main){
    when {
        replaceAll -> navigator.replaceAll(screen)
        replace -> navigator.navigate {
            it.dropLast(1) - screen + screen
        }
        else -> navigator.pushToFront(screen)
    }
}

The error is printed in the logs when you navigate or init your navigation on a non-main thread. There should be a stack trace pointing to the offending code.

Decompose

3.3.0-alpha02

is released! 👉 Added

isPredictiveBack

flag to the experimental`stackAnimation` function with selector Release notes: https://github.com/arkivanov/Decompose/releases/tag/3.3.0-alpha02

Hello, @Arkadii Ivanov, I'm currently making an app for iOs and I'm trying to use Predictive Back Gesture implementation from the documentation, which implements the Cupertino back swipe. But I ran into the following problem: if there is an element with horizontal scrolling on the screen (LazyRow for example), it stops scrolling normally because

Modifier.handleBackGestures

from

PredictiveBackGestureOverlay

is prioritized. Any ideas how to fix it?

@Arkadii Ivanov I have a childStack and in the first screen i have a bottom nav using childStack One back button press how can i move to a specific bottom nav tab and on next back press, close the app I tried using

BackCallback

but, it lands me back to that tab on back press, but on next back press it does not close the app I'm using

navigator.pop()

for this

All roads lead back to @Arkadii Ivanov 😂 https://github.com/gradle/gradle/issues/26091

Decompose

3.3.0-alpha03

is released! 👉 Updated Kotlin to

2.1.0

, Essenty to

2.4.0

, AGP to

8.7.3

, Gradle to

8.11.1

👉 Added

AnimatedVisibilityScope

to

ChildPanels

content composables 👉 Updated Essenty to

2.5.0-alpha01

Release notes: https://github.com/arkivanov/Decompose/releases/tag/3.3.0-alpha03

Hi, is it possible to use

childPanels()

navigation model and the

ListDetailPaneScaffold()

together instead of the

ChildPanels()

composable? It looks like the navigation models are so different that it doesn't seems to be possible. Maybe the only solution to use

ListDetailPaneScaffold()

with Decompose is to just call

childContent()

but not

childPanels()

?

Hi! Say that on a given component, I have a child slot. I want to expose a single

uiState

flow to my UI. As part of that UI State, if child slot is active, I want to provide the child instance, if it is not active I want to provide some other state data class. The way I see it, to do this, I would combine the

Value<ChildSlot<X, Y>>

with some other internal state flow. Question is: can I convert the

Value

into a StateFlow to allow me to combine it? Or is there any consequence of doing so, such as performance considerations or the like? I have a snippet that I think came from you @Arkadii Ivanov to do that conversion, I can paste on the thread.

Hello everyone. Using Decompose in a Compose multiplatform project. On iPhones they usually go back by swiping on the screen instead of using back arrows. Is there a possibility to enable going back on swipe for iPhones?

Decompose

3.3.0-beta01

is released! - Updated Essenty to

2.5.0-beta01

Release notes: https://github.com/arkivanov/Decompose/releases/tag/3.3.0-beta01

Hi everyone. I just tried using Decompose for navigation in my multiplatform project, and I’m a bit confused. I just watched Arkadii’s video here: . My question is, for nested navigation like this, do we need to create a screen for each parent component? For example, here we have the Signed Out and Signed In components. Do we need to create a composable SignedOutScreen and SignedInScreen as the parent composable for the child components/composables underneath?

Hey! I was wondering if

StateKeeper

`consume`/`register` methods could use the same technique (or have an overload) that

Json.encodeToString

does, so we don't have to pass the serializer manually, with something like

essentyJson.serializersModule.serializer()

? I think I can use

Json

instead of

essentyJson

and do an extension on my end, as the lib doesn't and is not expected to modify the

serializersModule

in the future, but it would be nicer to be shipped with the lib.

Hi guys and @Arkadii Ivanov, I have a question Let's say each

BottomNavigation

tab (

ExploreRootScreen

,

WalletRootScreen

and

ProfileRootScreen

) has it's own

ChildStack

@Composable
internal fun HomeRootScreen(component: HomeRootComponent) = Box(
    modifier = Modifier.fillMaxSize()
) {
    StackContent(component)
    BottomNavigation(component)
}

@Composable
private fun StackContent(component: HomeRootComponent) {
    val homeStack by component.stackRouter.subscribeAsState()
    Children(
        // ...
        content = { childStack -> childStack.instance.getContentByChild() }
    )
}

@Composable
private fun HomeRootChild.getContentByChild() = when (this) {
    // ...
    is ProfileRootChild -> ProfileRootScreen(this) // with ProfileRootComponent
}

BottomNavigation

is drawn over

StackContent

using

Alignment.Bottom

If we need to display a Dialog (

ChildSlot

) somewhere deep inside of tab's

ChildStack

, it should be drawn above

BottomNavigation

I created a diagram where

LogoutDialog

and

SwitchLanguageDialog

(marked with yellow color) should appear. Each child in the diagram (marked with blue, yellow and pink colors) has it's own

ChildComponent

(e.g,

LanguageComponent

and

SwitchLanguageComponent

) And as I understand Decompose, for

SwitchLanguageDialog

I should create

ChildSlot

inside

LanguageComponent

and this Dialog should be displayed on

LanguageScreen

That's ok, but it will be drawn under the BottomNavigation I assume I could create

ChildSlot

at

HomeRootComponent

level, but • I'm not sure how to handle different children from different nested screens (e.g, using

activeSlotChild: Flow<BaseSlotChild>

seems odd due to a large

when

check) • I don't know if this approach would break children back navigation (e.g, when Dialog is displayed, using system back swipe might trigger

ChildStack

's backHandler) How should I handle this properly? Thanks in advance

CleanShot 2025-02-25 at 17.46.27.jpg

Decompose

3.3.0

is released! Release notes: https://github.com/arkivanov/Decompose/releases/tag/3.3.0

I'd like to set up navigation state logging for Sentry. One of the problems is that I can't think of a way to log the navigation tree - I have a deep tree of nested components. It may be enough to just log the stack being updated, perfectly it would be nice to name the action, like push/pop/pushNew, it could have been done with comparing old/new count, but may not be accurate with replacing multiple items. Another issue is that I often store a model object in the config, and in the log I would only want to include limited info about the object, like object id. Feels like I would need to parse strings manually, as Kotlin serialization is not flexible enough to allow me to override the serialization logic for each object of a specific interface. Any chance someone has already worked on something like this?

Just wanted to say thanks for the library — my application architecture is much cleaner now, which has taken away a lot of stress and negative emotions, and I’m genuinely enjoying programming again 😊

In the release build with R8 I've got a crash from

typeOf

related to generic type

data class InstanceToRetain<T>(val value: T)

retainedSimpleInstance { InstanceToRetain(0) }

Looks like it's something you've faced already, what do you think is the best workaround here? For now I switched to

T::class

, it obviously loses nested

T

info, but at least it would crash in debug app version if I try to use the same key somewhere, so it's easier to catch during development.

Anyone used ChildPages with AndroidX Paging before? Is that at all possible? there is only List param when creating the initial pages, so just want to check to see if I am missing something. 🤔

@Arkadii Ivanov I want to track ScreenName for Analytics purpose, I have a 3 layer nested Navigation hierarchy So Root Level Screens, it has a HomeScreen which has bottom navigation, and then each bottom nav tab has a Pager in it. How would you suggest achieving ScreenName tracking in such a multi layer nav structure ? One way I could think of is listening to the activeItem changes in childPages and childStack, but will that handle proper name change when a back navigation happens in a layer above.

Hey. We’ve come across an unexpected behavior in an edge case. We’re using a bottom bar, and clicking on the tabs triggers the

bringToFront

function in RootComponent. If the user—_for some mysterious reason_—starts rapidly switching between tabs, the navigation can get stuck on one of the screens. When that happens, the screen becomes unresponsive to clicks. We share the RootComponent in android and iOS and it affects both. I also noticed the same issue in the sample Decompose app.

Hi I've faced the problem with predictive back navigation It worked great on Android and on iOS emulator, but it didn't work on real iPhone device And I found out that was because Compose

1.8.0-beta01

When I changed it with

1.7.3

---> 👍

I know decompose comes with dependency injection out of the box, but as my projects were growing I switched over to kotlin-inject and kotlin-inject-anvil and was getting tired of writing a bunch of boiler plate code for the binding assisted factory interfaces similar to dagger. Since decompose heavily relies on assisted injection of the

ComponentContext

, I wrote a library that extends kotlin-inject-anvil to help bind and generate the assisted factory interface glue code to bind it in the kotlin-inject dependency graph that I thought others who use the library might be interested in. https://plusmobileapps.com/blog/2025/04/04/kotlin-inject-anvil-extensions/

@Arkadii Ivanov I have this usecase I need to call a suspend function in my RootComponent, but i want this to be called before the ChildStack Components are created This function call clears my Room DB, what i have done now is call it inside the

doOnCreate

but i am facing a bug that it sometimes completes after the ChildComponent is created, which then crashes as the app as db goes empty I want it to complete first (success or failure), then the ChildStack child components to be created

@Arkadii Ivanov is there a way to perform something when the predictive back nav is cancelled ? I have achieved it like this, it works, but is it correct ? Code in thread

@Arkadii Ivanov Following on my post in #CJLTWPH7S, I used Decompose already but I wondering if it could work with Compose Adaptive Layout ? I saw the new Child Panels but is it possible to use eg

ListDetailPaneScaffold

with ?

Decompose

3.4.0-alpha01

is released! 👉 Use SPDX identifier in POMs 👉 Relax

StrictMode

with restarting the Activity stack for deep links 👉 Don't restart Activity stack when there is no deep link 👉 Added

backHandlerPriority

argument to

childContext

extension function 👉 Updated Compose to

1.8.0-rc01

and

compileSdkVersion

to 35 Release notes: https://github.com/arkivanov/Decompose/releases/tag/3.4.0-alpha01