jsonNavigatorSaver for kotlinx.Serialization for state restoration

[osrl]

This is not an issue but I didn't know where to put this. I've been trying to implement a NavigatorSaver to save and restore state of @Serializable data classes. I needed it because my multiplatform data classes had kotlinx.DateTime classes and they're not java.io.Serializable. I'm open to change my approach if you suggest me some other way to serialize DateTime classes.

If anyone needs it, here is how I've implemented it:

val screenSerializersModule = SerializersModule {
    polymorphic(Screen::class) {
        subclass(MyScreen::class, MyScreen.serializer())
        // Register other subclasses here
    }
}
val screenJson: Json
    get() = Json(defaultJson) {
        serializersModule = screenSerializersModule // Include the module here
    }

@OptIn(InternalSerializationApi::class)
fun isKotlinxSerializable(screenClass: KClass<*>): Boolean {
    return try {
        screenClass.serializerOrNull() != null
    } catch (e: Exception) {
        false
    }
}

@OptIn(
    ExperimentalVoyagerApi::class,
    InternalVoyagerApi::class
)
fun jsonNavigatorSaver() =
    NavigatorSaver { _, key, stateHolder, disposeBehavior, parent ->
        listSaver(
            save = { navigator ->
                navigator.items.map { screen ->
                    if (isKotlinxSerializable(screen::class)) {
                        screenJson.encodeToString(screen)
                    } else {
                        screen
                    }
                }
            },
            restore = { items ->
                // Deserialize the list of screens using custom Json configuration
                val restoredScreens = items.map { item ->
                    when (item) {
                        is String -> {
                            screenJson.decodeFromString(item) as Screen
                        }
                        else -> {
                            item as Screen
                        }
                    }
                }
                Navigator(restoredScreens, key, stateHolder, disposeBehavior, parent)
            }
        )
    }


CompositionLocalProvider(
    LocalNavigatorSaver provides jsonNavigatorSaver()
) { .... }

And your screen:

@Serializable
data class MyScreen(val myDataThatHasDateTimeField: MyData): Screen