Initializing an actor before being able to handle some other messages

Question

I have an actor which creates another one:

class MyActor1 extends Actor {
  val a2 = system actorOf Props(new MyActor(123))
}

The second ac

Answer 1

You could use become method to change actor's behavior after initialization:

class MyActor2(a: Int) extends Actor {

  server ! GetInitializationData

  def initialize(d: InitializationData) = ???

  //handle incoming messages
  val initialized: Receive = {
    case "job1" => // do some job but after it's initialized (bootstrapped) itself
  }

  def receive = {
    case d @ InitializationData =>
      initialize(d)
      context become initialized
  }
}

Note that such actor will drop all messages before initialization. You'll have to preserve these messages manually, for instance using Stash:

class MyActor2(a: Int) extends Actor with Stash {

  ...

  def receive = {
    case d @ InitializationData =>
      initialize(d)
      unstashAll()
      context become initialized
    case _ => stash()
  }
}

If you don't want to use var for initialization you could create initialized behavior using InitializationData like this:

class MyActor2(a: Int) extends Actor {

  server ! GetInitializationData

  //handle incoming messages
  def initialized(intValue: Int, strValue: String): Receive = {
    case "job1" => // use `intValue` and `strValue` here
  }

  def receive = {
    case InitializationData(intValue, strValue) =>
      context become initialized(intValue, strValue)
  }
}