Hi everyone! Some time ago, `Flow.onEmpty` operato...

# coroutines

[albertosh]

Hi everyone!
Some time ago, Flow.onEmpty operator was added (https://github.com/Kotlin/kotlinx.coroutines/issues/1890)
Is there any plan for including Flow.onNotEmpty?
Use case is a method that return paginated data and you need all the items

fun getData(page: Int, pageSize: Int): Flow<Item> = ...
fun getAllData() = getAllData(0, 5)

private fun getAllData(page: Int, pageSize: Int): Flow<Item> = flow {
  val data = getData(page, pageSize)
  emitAll(data)
  data.onNotEmpty { emitAll(getAllData(page + 1, pageSize) }
}

Maybe I’m not following a proper approach, some other ideas I had using count

private fun getAllData(page: Int, pageSize: Int): Flow<Item> = flow {
  val data = getData(page, pageSize)
  emitAll(data)
  if (data.count() == pageSize) {         // Since `count` does a `collect`, another flow is created
    emitAll(getAllData(page + 1, pageSize) 
  }
}

To avoid creating two flows per page, I tried with a SharedFlow but since it never ends you can’t invoke count

BTW, I’m intending to use it on backend side, so not sure if I can use the Paging Library from Jetpack

[Dominaezzz]

Instead of emitAll use collect and emit, then you can set an isEmpty flag.