Question

我有一个演员，可以在几个州。初始状态应该从外部传递：

class MyActor(openId: String, initialState: Receive) extends Actor {

  val connected: (String) => Receive = (openId: String) => {
    case AuthorizedOk(user) => context.become(authorized(user))
    ...
    case message => unhandled(message)
  }

  val authorized: (IUserInfo) => Receive = (user: IUserInfo) => {
    case SomeLogic => context.become(...)
    case message => unhandled(message)
  }

  def receive: Actor.Receive = initialState
}

我需要在构造函数中设置初始状态connected或authorized。当然它可能是其他一些功能。但我不明白如何实现这一目标：

new MyActor("id", ???)

Answer 1

我看到两种可能性

将状态传递给actor的preStart生命周期方法

或

在初始化actor实例时，有一个可用于传递状态的对象伴随。有些东西：

对象MyActor {

def props（initialState：YourState）= Props.actorOf（new MyActor（initialState））

}

此示例中的初始状态也不必是部分函数。您可以将其建模为案例类，并使用context.become在状态发生时在各个状态之间移动。

编辑：添加一个示例以使其更清晰！

sealed trait State
case object Authorized extends State
case object UnAuthorized extends State

class MyActor(state: State) extends Actor {
  def receive: Receive = {
   case state: State =>
     // do some logic
     val newState = someLogic(state)
     // evolve with the new state
     context.become(active(newState))
  }

  def active(newState: State): Receive = {
    // do the pattern matching on the state and evolve
  }

  override def preStart(): Unit = {
    super.preStart()
    // send the initial state to this actor
    self ! state
  }
}

如何在actor范围之外实现接收函数并将其传递给actor

1 个答案: