suspend fun loadData(id: Long) = flow {
    fetchData(id) <-- now this is blocking function, how can I launch it in non blocking mode?
    roomDao.select(id)
        .collect {
            emit(result)
        }
}.flowOn(<http://Dispatchers.IO|Dispatchers.IO>)

suspend fun fetchData(id) {
    // make http request here and put data into database
}

Hi all. How can I launch

fetchData

function in parallel from

flow {}

?

You could do

launch { fetchData(id) }

unfortunately there is no

launch

function inside

flow

builder

Wrap the whole body of the flow in

coroutineScope

suspend fun loadData(id: Long) = flow {
    coroutineScope {
        launch { fetchData(id) }
        roomDao.select(id)
            .collect {
                emit(result)
            }
    }
}.flowOn(<http://Dispatchers.IO|Dispatchers.IO>)

looks like it is exactly what I need! Thanks a lot!

Note that, in order to have

fetchData

to run in parallel with

roomDao.select...

, you must wrap then entire contents of the `flow`’s code inside

coroutineScope

. This is because

coroutineScope

suspends until all its children have finished, which would include the

launch { fetchData(id) }

. Then to keep things in parallel, the

roomDao.select...

need to be one of the `coroutineScope`’s children as well.

thank you for explanation, Anton!