Alternative flows based on condition for akka stream

Question

Have a stream with custom flows and at a certain stage I want to split the stream and have two alternative data handling which will merge again later.

E.g.

Answer 1

You can use Broadcast to split the stream, then you will able to use filter or collect on each of streams to filter required data.

val split = builder.add(Broadcast[Int](2))

Src -> F1 -> split -> filterCondA -> F3 -> F6 -> Merge -> Sink
                   -> filterCondB -> F4 -> F5 -> Merge

Also, there is Partition stage which handles the number of output ports and the map function from value to port number f: T => Int.

val portMapper(value: T): Int = value match {
  case CondA => 0
  case CondB => 1
}

val split = builder.add(Partition[T](2, portMapper))

Src -> F1 -> split -> F3 -> F6 -> Merge -> Sink
             split -> F4 -> F5 -> Merge

Maybe there is some simpler way.