👀 Views: 0 💬 Answers: 1 📅 Created: 2025-08-21

android liveData viewModel room network Kotlin

I've been working on this all day and I'm working on a project and hit a roadblock. I'm working on a project and hit a roadblock. I'm experiencing an issue where my UI is not reflecting the latest data from multiple LiveData sources in my ViewModel when observed. I've set up a ViewModel to manage data from both a Room database and a network call, but it seems like the UI is only updating from one source intermittently. Here’s a simplified version of my code: ```kotlin class MyViewModel : ViewModel() { private val _dataFromRoom = MutableLiveData<List<Item>>() val dataFromRoom: LiveData<List<Item>> = _dataFromRoom private val _dataFromNetwork = MutableLiveData<List<Item>>() val dataFromNetwork: LiveData<List<Item>> = _dataFromNetwork fun fetchRoomData() { viewModelScope.launch { _dataFromRoom.value = database.itemDao().getAllItems() } } fun fetchNetworkData() { viewModelScope.launch { val response = networkService.getItems() if (response.isSuccessful) { _dataFromNetwork.value = response.body() } } } } ``` In my Activity, I observe both LiveData sources like this: ```kotlin viewModel.dataFromRoom.observe(this, Observer { items -> updateUIWithRoomData(items) }) viewModel.dataFromNetwork.observe(this, Observer { items -> updateUIWithNetworkData(items) }) ``` The problem arises when I call `fetchRoomData()` and `fetchNetworkData()` in quick succession. Sometimes, the UI only updates with data from the Room database, and I suspect that there might be a race condition or lifecycle issue at play. I’ve ensured that `fetchRoomData()` and `fetchNetworkData()` are called on the appropriate lifecycle events, but I still see this inconsistent behavior. I've tried adding a `MediatorLiveData` to combine the two sources and notify observers whenever either one changes, but it hasn't resolved the issue. Here’s how I attempted to implement that: ```kotlin val combinedData = MediatorLiveData<List<Item>>().apply { addSource(dataFromRoom) { value = it } addSource(dataFromNetwork) { value = it } } ``` Still, the UI is not reflecting the latest data correctly, and I occasionally receive "No data available" in the UI despite there being valid data in both sources. Any suggestions on how I can properly manage multiple LiveData sources in this scenario to ensure the UI remains in sync? Are there best practices I should follow? Thanks in advance! Any ideas what could be causing this? I'm coming from a different tech stack and learning Kotlin. For reference, this is a production service. Is this even possible? I'm on CentOS using the latest version of Kotlin. Thanks for your help in advance!