Scala侦听器/观察者 [英] Scala Listener/Observer

问题描述

通常，在Java中，当我有一个对象正在向其他对象提供某种通知时，我将采用Listener/Observer模式.

Typically, in Java, when I've got an object who's providing some sort of notification to other objects, I'll employ the Listener/Observer pattern.

是否有更像Scala的方式来做到这一点?我应该在Scala中使用这种模式，还是我应该利用的语言中还包含其他一些东西?

Is there a more Scala-like way to do this? Should I be using this pattern in Scala, or is there something else baked into the language I should be taking advantage of?

推荐答案

您仍然可以积累一系列的回调，但是您可以使它们发挥作用，而不必提出另一个单独的方法接口.

You can still accumulate a list of callbacks, but you can just make them functions instead of having to come up with yet another single method interface.

例如

case class MyEvent(...)

object Foo { 
  var listeners: List[MyEvent => ()] = Nil

  def listen(listener: MyEvent => ()) {
    listeners ::= listener
  }

  def notify(ev: MyEvent) = for (l <- listeners) l(ev) 
}

也请阅读此这有点相关纸(如果您想服用红色药丸). :)

Also read this this somewhat-related paper if you feel like taking the red pill. :)

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