1.4, MutableStateList.toList not compatible with SavedStateHandle?

# compose

[Andy Himberger]

1.4, MutableStateList.toList not compatible with SavedStateHandle?

[Andy Himberger]

maybe it wasn't supposed to work before, but we have been doing this for awhile to take a mutableStateList and store it in a SavedStateHandle by calling .toList() on it. (since this mutablestatelist is in a viewmodel not a rememberSaveable).

with 1.4 I know it exposes the internals instead of making a copy, but that results in this:

java.lang.IllegalArgumentException: Can't put value with type class androidx.compose.runtime.external.kotlinx.collections.immutable.implementations.immutableList.SmallPersistentVector into saved state
 	at androidx.lifecycle.SavedStateHandle.set(SavedStateHandle.kt:249)

[Andy Himberger]

(using lifecycle 2.6.0-rc01)

[Ian Lake]

Is there a reason you aren't using SavedStateHandle's built in support for Composable state? That uses the right autoSaver

[Andy Himberger]

Oh let me try that, this code has been around for awhile maybe before we had lifecycle 2.5

[Andy Himberger]

I can't use a mutableStateList with that though, I have to use simple state with a list member?

[Ian Lake]

Our samples show both usages of mutableStateListOf , mutableStateMapOf, and mutableStateOf, they're all supported. https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:lifecycl[…]/viewmodel/compose/samples/LifecycleViewModelSamples.kt;l=202

[Andy Himberger]

Ok sure, those examples are custom extracting/rebuilding it the mutablestatelist, I can try that. That should work..

[Vipulyaara]

We are facing the same crash after compose update to 1.4. Creating a new list from MutableStateList works fine but MutableStateList.toList cannot be serialized. Is it a known issue?