Troubleshooting

• What is the equivalent of interrupting Actions in GlobalSettings for WebSockets? What if we want to refuse a WebSocket connection when certain headers are missing? Something similar to the following code snippet didn't work as expected:

  override def onRouteRequest(request: RequestHeader): Option[Handler] = {
      if(request.path.startsWith("/ws")){
        Option(controllers.Default.error)
      } else
        super.onRouteRequest(request)
    }

  Interrupting WebSocket from the global object does not work as it does for Actions. However, there are other means of doing so: by using the tryAccept and tryAcceptWithActor methods. A WebSocket definition can be replaced by the following code:

  def wsWithHeader = WebSocket.tryAccept[String] {
      rh =>
        Future.successful(rh.headers.get("token") match {
          case Some(x) =>
            var channel: Concurrent.Channel[String] = null
            val out = Concurrent.unicast[String] {
              ch =>
                channel = ch
     ...