Error When Using Paging 3 with Retrofit and Coroutine in Android 14
I'm performance testing and I've searched everywhere and can't find a clear answer... I'm facing an issue while trying to implement Paging 3 with Retrofit and Coroutines in my Android application targeting API level 34. The goal is to fetch data from a REST API and display it in a RecyclerView using Paging Data. However, I keep getting an `IllegalStateException` with the message `The PagingSource must be initialized` when trying to load the initial data. Here's a simplified version of my PagingSource implementation: ```kotlin class MyPagingSource(private val apiService: ApiService) : PagingSource<Int, MyData>() { override suspend fun load(params: LoadParams<Int>): LoadResult<Int, MyData> { val pageNumber = params.key ?: 1 return try { val response = apiService.getData(pageNumber) LoadResult.Page( data = response.data, prevKey = if (pageNumber == 1) null else pageNumber - 1, nextKey = if (response.data.isEmpty()) null else pageNumber + 1 ) } catch (e: Exception) { LoadResult.Error(e) } } override fun getRefreshKey(state: PagingState<Int, MyData>): Int? { return state.anchorPosition?.let { anchorPosition -> state.closestPageToPosition(anchorPosition)?.prevKey?.plus(1) ?: state.closestPageToPosition(anchorPosition)?.nextKey?.minus(1) } } } ``` I initialize my PagingSource in the ViewModel like this: ```kotlin class MyViewModel(private val apiService: ApiService) : ViewModel() { val pager = Pager(PagingConfig(pageSize = 20)) { MyPagingSource(apiService) }.flow.cachedIn(viewModelScope) } ``` In my Fragment, I collect the flow from the ViewModel: ```kotlin lifecycleScope.launchWhenStarted { viewModel.pager.collectLatest { pagingData -> adapter.submitData(pagingData) } } ``` I've ensured that my API service is working properly and returning data in the expected format. The issue arises when I try to load the data for the first time, resulting in the `IllegalStateException`. I’ve also checked for potential issues with lifecycle scope and coroutine context. I've tried clearing the app data and reinstalling the app to rule out any caching issues. Any insights on what might be causing this error? I'm working on a CLI tool that needs to handle this. Is there a better approach? What's the correct way to implement this?