If I want to create a Flow that need the value of another Flow as input parameter, is `flatMapLatest...

# coroutines

[adte]

If I want to create a Flow that need the value of another Flow as input parameter, is flatMapLatest the function I should be using?

[Francesc]

flatMapLatest generates a new flow for each emission of the original flow, is that what you want?

[adte]

@Francesc No, I don't think so. Should I just use map then?

[adte]

I don't want map, because I end up with a Flow<Flow<T>>. I want to use the latest value of the input flow to generate a new flow

[adte]

I guess I'm looking at flatMapConcat then

[Francesc]

Do you want the first flow first value only, or do you want to observe all emissions of the first flow?

[adte]

All emissions yeah

[Francesc]

And you want one further emission from each or multiple?

[adte]

I want both flows to keep emitting

[Francesc]

How are their outputs related?

[Francesc]

i.e what do you want as result

[adte]

Each flow I'm querying a table, but the first flow value has the row id that I need to do the second query

[Francesc]

That sounds like flatMapLatest, for each row ID emission you emit a set of items belonging to that row

[adte]

@Francesc Thanks for confirming. all these functions get quite confusing 🙂

[Patrick Steiger]

flatMapLatest - aborts inner flow when new value from outer flow arrives
flatMapConcat - waits for inner flow to finish (emits all value from it) before processing new values from outer flow
flatMapMerge - for each new value from outer flow, emits all value from inner flows concurrently