Source.future

Send the single value of the Future when it completes and there is demand.

Source operators

Signature

Source.futureSource.future

Description

Send the single value of the Future when it completes and there is demand. If the future fails the stream is failed with that exception.

For the corresponding operator for the Java standard library CompletionStage see completionStage.

Example

Scala
source
import akka.actor.ActorSystem import akka.stream.scaladsl._ import akka.{ Done, NotUsed } import scala.concurrent.Future val source: Source[Int, NotUsed] = Source.future(Future.successful(10)) val sink: Sink[Int, Future[Done]] = Sink.foreach((i: Int) => println(i)) val done: Future[Done] = source.runWith(sink) //10

Reactive Streams semantics

emits the future completes

completes after the future has completed

Found an error in this documentation? The source code for this page can be found here. Please feel free to edit and contribute a pull request.