Mixing akka-http routing with actors

[Brian Topping]

Hi all,

I'd like to use the routing DSL to wrap a call to an actor. This used to be dirt simple, just send a message of "_" to the actor. Things are different now.

Here is the template of the actor-less server:

    val bindingFuture = (IO(Http) ? Http.Bind(interface = "0.0.0.0", port = 9000)).mapTo[Http.ServerBinding]
    handleConnections(bindingFuture) withRoute {
      get {
        pathPrefix("document" / Segment) {
          docId =>  {

            // what goes here?
          }
        }
      }
    }

Trivially, with the "actor" consuming a "case class Message" and returning a "case class Result(s: String)" I believe it looks something like this:

    val bindingFuture = (IO(Http) ? Http.Bind(interface = "0.0.0.0", port = 9000)).mapTo[Http.ServerBinding]
    handleConnections(bindingFuture) withRoute {
      get {
        pathPrefix("document" / Segment) {
          docId =>  {
            Future[RouteResult] {
              actor ? Message onComplete {
                case Success(Result(s)) => Complete(HttpResponse(200, s))
              }
            }           
          }
        }
      }
    }

In reality, much missing. Could I beg some pointers from the oracles?

Cheers, Brian

[Johannes Rudolph]

Hi Brian,

everything is now Future-based instead of relying on RequestContext's
side-effects as in spray. Apart from that, not much changed. So, just
use the Akka ask pattern and either A) complete with the future if you
have a Marshaller available or otherwise B) use the `onComplete` or
`onSuccess` directives to continue working with the result of the
Future:

A)

pathPrefix("document" / Segment) {
docId => complete((actor ? Message).mapTo[Result])
}

B)

pathPrefix("document" / Segment) {
docId =>

onSuccess((actor ? Message).mapTo[Result]) { (r: Result) =>
// put another route here
}
}

Both would have worked the same way in spray.

HTH
Johannes

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--
Johannes

-----------------------------------------------
Johannes Rudolph
http://virtual-void.net

[Brian Topping]

Got it, thanks!

Is there a way to do this that doesn't include using "complete"? For instance, if I wanted to get access to the request and response objects. Maybe that's not realistic inside the DSL.

Cheers, Brian

[Mathias Doenitz]

Brian,

the DSL is flexible enough to enable access to anything you want… :)
So, if you want to get a hold of the domain object that is marshalled into a response, no problem (one way would be the `onSuccess` directive).
If you want to get a hold of the HttpResponse produced by marshalling your domain response object, that’s also possible.

What exactly are you trying to do?

Cheers,
Mathias

---
mat...@spray.io
http://spray.io

[Mutaz Qasem]

I'm still not able to understand why this doesn't work in the routing DSL

future onComplete {
case Success(result) => complete(result) //complete HTTP response
case Failure(failure) => complete(failure)
}

OR

future onSuccess {
case res => complete(res)
}
future onFailure {
case failure => complete(failure)
}

But anyway, my question is, how can I handle failure and send a failure message to the client? I can find only onSuccess in akka.http.scaladsl.server.Directives . Is there a way to have onFailure?