CODEWITHSUNDEEP
scalaakka
Eugene Zhulenev
Eugene Zhulenev

Reputation: 9734

Construct scala/akka Future from callback

I have such code example

val request: Defered[Int] = client.getSomeIntAsynFromSocket();

request.addCallBack(result => result.success[String])
request.addErrback(error => error.fail[Integer])

How is it possible to construct Future[Validation[String, Int]] from defered 'request' and available callbacks

==============================================

Solution from my own:

val f = Future {
    val queue = java.util.concurrent.ArrayBlockingQueue[Validation[String, Int]](1)

    val request: Defered[Int] = client.getSomeIntAsynFromSocket();
    request.addCallBack(result => queue.add(result.success[String]))
    request.addErrback(error => queue(error.fail[Integer]))

    f.take
}

Upvotes: 1

Views: 457

Answers (1)

Viktor Klang
Viktor Klang

Reputation: 26579

For Akka 2.x, put the method below somewhere you can reuse it by import.

def asFuture[T](d: Defered[T])(implicit e: ExecutionContext): Future[T] = {
  val p = Promise[T]()
  d.addCallback(r => p tryComplete Right(r))
  d.addErrback(e => p tryComplete Left(e))
  p.future
}

val f = asFuture(client.getIntAsynFromSocket())

Upvotes: 4

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