How can I set an initial state when mapping a flow...

# coroutines

[Odinakachukwu Omaka-chukwu]

How can I set an initial state when mapping a flow.

Here's an example that explains what I mean:

val dataUiState: StateFlow<UiState<Data>> = queryFlow
        .debounce(300)
        .mapLatest {
            // How to set state to UiState.Loading while request is still running

            // Get new data based on filter
            val data = requestData(it)
           UiState.Success(data)
        }.stateIn(viewModelScope, SharingStarted.WhileSubscribed(), UiState.Loading)

I would like to reset the state to UiState.Loading while the data request is still fetching.

[Zach Klippenstein (he/him) [MOD]]

Instead of mapLatest you could use flatMapLatest and make a flow that starts with loading, or probably simpler to just use transformLatest and emit loading before emitting the load result.

[streetsofboston]

Or update queryFlow's state outside of the chain of transformations forming dataUiState.

dataUiState.update { .... requestData(it) ... }

in another method that would initiate the requestData call

[Odinakachukwu Omaka-chukwu]

Thanks, transformLatest was exactly what I needed