ActorPublisher as Comet Event Source in Play Application

Question

I'm trying to write an Actor which connects to an Amazon Kinesis stream and then relays any messages received via Comet to a Web UI. I'm using Source.actorPublisher for this and using the json method with Comet in Play described here. I got the events working just fine using Source.tick(), but when I tried using an ActorPublisher, the Actor never seems to be sent any Request messages as expected. How are requests for data usually sent down an Akka flow? I'm using v2.5 of the Play Framework.

My controller code:

def subDeviceSeen(id: Id): Action[AnyContent] = Action {
  val deviceSeenSource: Source[DeviceSeenMessage, ActorRef] = Source.actorPublisher(DeviceSeenEventActor.props)
  Ok.chunked(deviceSeenSource
    .filter(m => m.id == id)
      .map(Json.toJson(_))
        via Comet.json("parent.deviceSeen")).as(ContentTypes.JSON)
}

Am I doing anything obviously wrong in the above? Here is my Actor code:

object DeviceSeenEventActor {
  def props: Props = Props[DeviceSeenEventActor]
}

class DeviceSeenEventActor extends ActorPublisher[DeviceSeenMessage] {

implicit val mat = ActorMaterializer()(context)

val log = Logging(context.system, this)

def receive: Receive = {
  case Request => log.debug("Received request message")
                  initKinesis()
                  context.become(run)
  case Cancel => context.stop(self)
}

def run: Receive = {
  case vsm:DeviceSeenMessage => onNext(vsm)
                                 log.debug("Received request message")
                                 onCompleteThenStop() //we are currently only interested in one message
  case _:Any                  => log.warning("Unknown message received by event Actor")
}

private def initKinesis() = {
  //init kinesis, a worker is created and given a reference to this Actor.
  //The reference is used to send messages to the actor.
}

}

The 'Received request message' log line is never displayed. Am I missing some implicit? There are no warnings or anything else obvious displayed in the play console.

Answer 1

The issue was that I was pattern matching on case Request => ... instead of case Request() => .... Since I didn't have a default case in my receive() method, the message was simply dropped by the Actor.