why does my factory being invoked when I navigate back to this composable I m using jetpack navigation as well ``` private val factory = InvalidatingPagingSourceFactory FeedSource pages value api val items Flow lt PagingData lt FeedItem gt gt = Pager PagingConfig 20 factory invoke flow``` composable ``` Composable fun FeedScreen factory ViewModelProvider Factory onItemClick Long gt Unit val viewModel = viewModel lt MainViewModel gt factory = factory val items = viewModel items collectAsLazyPagingItems LazyColumn content = items items item gt if item = null RealRowItem item = item onItemClick = onItemClick else PlaceholderRowItem ```

private val factory = InvalidatingPagingSourceFactory { FeedSource(pages.value, api) }

    val items: Flow<PagingData<FeedItem>> = Pager(PagingConfig(20)) {
        factory.invoke()
    }.flow

composable

Copy code

@Composable
fun FeedScreen(factory: ViewModelProvider.Factory, onItemClick: (Long) -> Unit) {
    val viewModel = viewModel<MainViewModel>(factory = factory)
    val items = viewModel.items.collectAsLazyPagingItems()

    LazyColumn(content = {
        items(items) { item ->
            if (item != null) {
                RealRowItem(item = item, onItemClick = onItemClick)
            } else {
                PlaceholderRowItem()
            }
        }
    })
}

Ian Lake

02/17/2021, 8:36 PM

Do you mean your

InvalidatingPagingSourceFactory

or your

ViewModelProvider.Factory

? If the former, it looks like you're missing a `cachedIn(viewModelScope)`: https://developer.android.com/topic/libraries/architecture/paging/v3-paged-data#pagingdata-stream

You still need that line

aperfilyev

02/17/2021, 9:03 PM

cachedIn(viewModelScope)

exactly, thanks!

2 Views