advanced patterns with Navigation Component and Shared ViewModel in Android 14
I've tried everything I can think of but I keep running into Does anyone know how to I'm sure I'm missing something obvious here, but I'm working with an scenario when using the Navigation Component along with a Shared ViewModel in my Android 14 application. Specifically, when I navigate from Fragment A to Fragment B, and then back to Fragment A, the state of my Shared ViewModel seems to be lost or reset, causing my UI to not reflect the latest data. I've confirmed that I'm using the same ViewModel instance across both fragments, but the data in the ViewModel does not continue as expected. Here is how I'm setting up my ViewModel: ```kotlin class SharedViewModel : ViewModel() { var data: String? = null } ``` In Fragment A, I obtain the ViewModel like this: ```kotlin class FragmentA : Fragment() { private val sharedViewModel: SharedViewModel by activityViewModels() override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) sharedViewModel.data = "Some data" } } ``` Then in Fragment B: ```kotlin class FragmentB : Fragment() { private val sharedViewModel: SharedViewModel by activityViewModels() override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) Log.d("FragmentB", "Data: ${sharedViewModel.data}") } } ``` After navigating back to Fragment A, when I check the data in `onViewCreated`, it appears to be null. I've tried overriding `onSaveInstanceState` to save the state, but it doesn't seem to help with the ViewModel. I am also not using any `LiveData` here; it's simply a variable. I read that ViewModels should retain their data through configuration changes, but it seems like navigating back and forth is causing it to reset. Has anyone encountered something similar? What could be going wrong in my setup? Is there a better way to manage shared state between fragments when using the Navigation Component? Any help would be greatly appreciated. I'm working on a application that needs to handle this. What's the best practice here? My development environment is macOS. How would you solve this? For reference, this is a production web app. I recently upgraded to Kotlin 3.11. Thanks for any help you can provide! I'm working on a CLI tool that needs to handle this. Thanks for your help in advance!