Is there any operator for `Flow lt Flow lt T gt gt ` like `flatten ` which can cancel child flow collection when a new parent value is emitted Say you have ```fun parentFlow Flow lt String gt = fun childFlow id String Flow lt Result gt = id comes from parentFlow``` My goal is to have a single `Flow lt Result gt ` taking the id from parent flow One way to do this is ```val merged Flow lt Flow lt Result gt gt = parentFlow map childFlow it val flat Flow lt Result gt = merged flattenConcat ``` However in my case the parent id represents a kind of state so when a new id is emitted the flow should stop collecting the previous `childFlow` I m struggling to find an elegant way to do this I could collect the child inside the parent body inside `flow ` for example but then not sure how to cancel the previous one

Do you mean `Flow lt T gt flatMapLatest`

Is there any operator for `Flow lt Flow lt T gt gt ` like `f kotlinlang #coroutines

02/12/2021, 4:49 PM

Is there any operator for

Flow<Flow<T>>

flatten*

which can cancel child flow collection when a new parent value is emitted? Say you have

fun parentFlow(): Flow<String> = ...
fun childFlow(id: String): Flow<Result> = ... // id comes from parentFlow

My goal is to have a single

Flow<Result>

, taking the id from parent flow. One way to do this is:

val merged: Flow<Flow<Result>> = parentFlow().map { childFlow(it) }
val flat: Flow<Result> = merged.flattenConcat()

However in my case the parent id represents a kind of state, so when a new id is emitted, the flow should stop collecting the previous

childFlow

. I'm struggling to find an elegant way to do this. I could collect the child inside the parent body (inside

flow { }

for example), but then not sure how to cancel the previous one

02/12/2021, 4:52 PM

Flow<T>.flatMapLatest

02/12/2021, 5:05 PM

That's perfect! Thank you!

02/14/2021, 9:17 PM

Why isnt there a .flattenLatest() like flattenMerge()?