I am using `avedInstanceState`in dev14 but getting this error `cannot be saved using the current UiS...

# compose

[amar_1995]

I am using `avedInstanceState`in dev14 but getting this error
cannot be saved using the current UiSavedInstanceStateRegistry. The default implementation only supports types which can be stored inside the Bundle. Please consider implementing a custom Saver for this class and pass it to savedInstanceState() or rememberSavedInstanceState()

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

What type are you trying to save?

[amar_1995]

Custom object

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

That error message is pretty clear imo, what part doesn’t make sense?

[amar_1995]

Do I need to add saver in custom object part ?

[Foso]

dev14 or dev17?

[amar_1995]

dev14

[Foso]

try dev17

[amar_1995]

okay

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

You pass the saver to rememberSavedInstanceState

[amar_1995]

val navigationSaver = Saver<NavigationStack<MainScreen>, NavigationStack<MainScreen>>(
    save = { it },
    restore = {  NavigationStack(init = MainScreen.Watchlist) }
)

this.navigation = rememberSavedInstanceState<NavigationStack<MainScreen>>(saver = navigationSaver) {
    NavigationStack(init = MainScreen.Watchlist)
}

Above code is giving me java.lang.IllegalStateException: Check failed. error

[amar_1995]

Check failed.
at androidx.ui.savedinstancestate.ValueProvider$updateAndReturnValue$1.invoke(RememberSavedInstanceState.kt:106)
at androidx.ui.savedinstancestate.UiSavedStateRegistryImpl.performSave(UiSavedStateRegistry.kt:116)
at androidx.ui.core.SavedStateDelegate.dispatchSaveInstanceState(SavedStateDelegate.kt:106)
`at androidx.ui.core.AndroidComposeView.dispatchSaveInstanceState(AndroidComposeView.kt:690)``

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

Is NavigationStack Serializable or Parcelable? The error message you posted initially says “The default implementation only supports types which can be stored inside the Bundle”

[amar_1995]

It is niether. It just a simple class

[amar_1995]

https://cs.android.com/androidx/platform/frameworks/support/+/androidx-master-dev:compose/runtime/runtime-saved-instance-state/samples/src/main/java/androidx/compose/runtime/savedinstancestate/samples/Samples.kt;l=45?q=CustomSaverSample&ss=androidx%2Fplatform%2Fframeworks%2Fsupport

[amar_1995]

I am trying do the above same way

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

Right, so you need to return something from the save lambda that can be stored in a Bundle.

[amar_1995]

Is there any example for this ?

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

The example you posted does it. It returns/restores Holder.value, which is an Int, i.e. something that can be stored in a Bundle.

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

The saver is basically your serialization/deserialization logic, but instead of serializing to a byte array, you’re serializing to any of the types supported by Bundle.

[amar_1995]

Got your point thanks