pekko/akka-docs/scala/code/akka/docs/extension/ExtensionDocSpec.scala
Roland d5c23bcb76 add ExtendedActorSystem to shield ActorSystemImpl
- add provider, guardian, systemGuardian and deathWatch to it
- make ActorSystemImpl extend ExtendedActorSystem
- use ExtendedActorSystem for creating extensions, thereby limiting the
  access extensions get to just those four published methods.
2012-01-24 11:33:40 +01:00

76 lines
1.8 KiB
Scala

/**
* Copyright (C) 2009-2012 Typesafe Inc. <http://www.typesafe.com>
*/
package akka.docs.extension
import java.util.concurrent.atomic.AtomicLong
import akka.actor.Actor
import akka.testkit.AkkaSpec
//#extension
import akka.actor.Extension
class CountExtensionImpl extends Extension {
//Since this Extension is a shared instance
// per ActorSystem we need to be threadsafe
private val counter = new AtomicLong(0)
//This is the operation this Extension provides
def increment() = counter.incrementAndGet()
}
//#extension
//#extensionid
import akka.actor.ExtensionId
import akka.actor.ExtensionIdProvider
import akka.actor.ExtendedActorSystem
object CountExtension
extends ExtensionId[CountExtensionImpl]
with ExtensionIdProvider {
//The lookup method is required by ExtensionIdProvider,
// so we return ourselves here, this allows us
// to configure our extension to be loaded when
// the ActorSystem starts up
override def lookup = CountExtension
//This method will be called by Akka
// to instantiate our Extension
override def createExtension(system: ExtendedActorSystem) = new CountExtensionImpl
}
//#extensionid
object ExtensionDocSpec {
//#extension-usage-actor
class MyActor extends Actor {
def receive = {
case someMessage
CountExtension(context.system).increment()
}
}
//#extension-usage-actor
//#extension-usage-actor-trait
trait Counting { self: Actor
def increment() = CountExtension(context.system).increment()
}
class MyCounterActor extends Actor with Counting {
def receive = {
case someMessage increment()
}
}
//#extension-usage-actor-trait
}
class ExtensionDocSpec extends AkkaSpec {
import ExtensionDocSpec._
"demonstrate how to create an extension in Scala" in {
//#extension-usage
CountExtension(system).increment
//#extension-usage
}
}