Android ViewModel Not Retaining State with Custom LiveData Transformation
I'm collaborating on a project where I can't seem to get Quick question that's been bugging me - I'm experiencing an scenario where my `ViewModel` does not retain state after a configuration change, specifically when I use a custom `LiveData` transformation. I have a `LiveData` stream from a `Repository` which fetches user data, and I apply a transformation to it. However, after a screen rotation, the transformed `LiveData` seems to lose its state and I get a fresh data load instead of the cached data. Here’s a snippet of my `ViewModel`: ```kotlin class UserViewModel(private val repository: UserRepository) : ViewModel() { private val _userLiveData = repository.getUserData().map { user -> // Custom transformation logic user.name.uppercase() } val userLiveData: LiveData<String> = _userLiveData } ``` My `Activity` observes this `userLiveData` like this: ```kotlin class UserActivity : AppCompatActivity() { private lateinit var viewModel: UserViewModel override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) viewModel = ViewModelProvider(this).get(UserViewModel::class.java) viewModel.userLiveData.observe(this, Observer { userName -> // Update UI with userName }) } } ``` The `getUserData()` method in my `Repository` fetches data from a local database using Room and returns a `LiveData<User>` object. Here’s how it looks: ```kotlin fun getUserData(): LiveData<User> { return userDao.getUser().asLiveData() } ``` The question occurs when I rotate the device; I see a log message indicating that the data is being fetched again, which leads me to suspect that the transformation is not being retained. I also verified that my `UserRepository` is a singleton and I am using the latest version of AndroidX libraries (androidx.lifecycle:lifecycle-viewmodel-ktx:2.5.1). Is there a better way to manage state with transformed `LiveData` in a `ViewModel`? What am I missing here? Any help would be appreciated! Has anyone else encountered this? For reference, this is a production CLI tool. Any advice would be much appreciated.