gistfile1.scala

val observer = new Observer[OnEvent] {
    override def onNext(value: OnEvent) {
      case OnEvent("Hi!", args, context) =>
        if (value.packet.hasAckData) {
          value.ack("[]")
        }
        value.reply("welcome", List(Msg("Greeting")).toJson.toString)
    }
  }

  val channel = Subject[OnData]()
  channel.ofType[OnEvent].filter(_.name == "Hi!").subscribe(observer)

  namespaceExt.namespace("test") ! Namespace.Subscribe(channel)