How to use Akka actors to handle HTTP requests in Akka

Question

I am new to Akka HTTP and Scala in general. I was trying to handle HTTP requests using Akka actors. When the HTTP request is encountered, the corresponding child actor gets activated. Currently this is my actor logic:

trait CorsDirective extends BasicDirectives { actor: Actor =>

  private def createResponder(requestContext: RequestContext) = {
    context.actorOf(Props(new CorsResponder(requestContext)))
  }

  val corsRoute = {
    path("corsdirective") {
      get {
        requestcontext =>
          val corsresponder = createResponder(requestcontext)
          corsresponder ! "corsdirectiveactiviated"
      }
    }
  }
}

class CorsResponder(requestcontext: RequestContext) extends Actor {

  override def receive: Receive = {
    case String => requestcontext.complete("The cors directive was called here")
  }
}

Now how do I plug into my main program, which is like this:

object AncileService01 extends App {
  val config = ConfigFactory.load()
  val host = config.getString("http.host")
  val port = config.getInt("http.port")

  implicit val system = ActorSystem("My-ActorSystem")
  implicit val executionContext = system.dispatcher
  implicit val materializer = ActorMaterializer()

  val api = corsRoute

  Http().bindAndHandle(api, host, port)
}

Answer 1

When your CorsResponder receives a message, you want to reply to sender. So do something like this:

class CorsResponder(requestcontext: RequestContext) extends Actor {

  override def receive: Receive = {
    case String => sender ! "The cors directive was called here"
  }
}

Use ask pattern to complete your request:

import akka.pattern.ask
import context.dispatcher // You will want to pass it to corsRoute as its argument

(corsresponder ? "corsdirectiveactiviated").mapTo[String] { result =>
    case message => complete(message)
}