All messages sent to the akka.actor.FSM will be wrapped inside an
Event, which allows pattern matching to extract both state and data.
Case class representing the state of the akka.actor.FSM whithin the
onTermination block.
This extractor is just convenience for matching a (S, S) pair, including a reminder what the new state is.
This case object is received in case of a state timeout.
Cancel named timer, ensuring that the message is not subsequently delivered (no race).
Cancel named timer, ensuring that the message is not subsequently delivered (no race).
of the timer to cancel
Sends the supplied message to all current listeners using the provided sender as sender.
Sends the supplied message to all current listeners using the provided sender as sender.
Produce transition to other state.
Produce transition to other state. Return this from a state function in order to effect the transition.
state designator for the next state
state transition descriptor
Verify existence of initial state and setup timers.
Verify existence of initial state and setup timers. This should be the last call within the constructor.
Chain this into the receive function.
Chain this into the receive function.
def receive = listenerManagement orElse Return next state data (available in onTransition handlers)
Set handler which is called upon termination of this FSM actor.
Set handler which is called upon termination of this FSM actor. Calling this method again will overwrite the previous contents.
Set handler which is called upon each state transition, i.
Set handler which is called upon each state transition, i.e. not when staying in the same state. This may use the pair extractor defined in the FSM companion object like so:
onTransition {
case Old -> New => doSomething
}
It is also possible to supply a 2-ary function object:
onTransition(handler _)
private def handler(from: S, to: S) { ... }
The underscore is unfortunately necessary to enable the nicer syntax shown above (it uses the implicit conversion total2pf under the hood).
Multiple handlers may be installed, and every one of them will be called, not only the first one matching.
Call onTermination hook; if you want to retain this behavior when
overriding make sure to call super.postStop().
Call onTermination hook; if you want to retain this behavior when
overriding make sure to call super.postStop().
Please note that this method is called by default from preRestart(),
so override that one if onTermination shall not be called during
restart.
Set state timeout explicitly.
Set state timeout explicitly. This method can safely be used from within a state handler.
Schedule named timer to deliver message after given delay, possibly repeating.
Schedule named timer to deliver message after given delay, possibly repeating.
identifier to be used with cancelTimer()
message to be delivered
delay of first message delivery and between subsequent messages
send once if false, scheduleAtFixedRate if true
current state descriptor
Set initial state.
Set initial state. Call this method from the constructor before the #initialize method.
initial state designator
initial state data
state timeout for the initial state, overriding the default timeout for that state
Return current state data (i.
Return current state data (i.e. object of type D)
Return current state name (i.
Return current state name (i.e. object of type S)
Produce "empty" transition descriptor.
Produce "empty" transition descriptor. Return this from a state function when no state change is to be effected.
descriptor for staying in current state
Produce change descriptor to stop this FSM actor including specified reason.
Produce change descriptor to stop this FSM actor including specified reason.
Produce change descriptor to stop this FSM actor with reason "Normal".
Inquire whether the named timer is still active.
Inquire whether the named timer is still active. Returns true unless the timer does not exist, has previously been canceled or if it was a single-shot timer whose message was already received.
Convenience wrapper for using a total function instead of a partial function literal.
Convenience wrapper for using a total function instead of a partial function literal. To be used with onTransition.
Insert a new StateFunction at the end of the processing chain for the given state.
Insert a new StateFunction at the end of the processing chain for the given state. If the stateTimeout parameter is set, entering this state without a differing explicit timeout setting will trigger a StateTimeout event; the same is true when using #stay.
designator for the state
default state timeout for this state
partial function describing response to input
Set handler which is called upon reception of unhandled messages.
Set handler which is called upon reception of unhandled messages. Calling this method again will overwrite the previous contents.
The current state may be queried using stateName
Finite State Machine actor trait. Use as follows:
object A { trait State case class One extends State case class Two extends State case class Data(i : Int) } class A extends Actor with FSM[A.State, A.Data] { import A._ startWith(One, Data(42)) when(One) { case Event(SomeMsg, Data(x)) => ... case Ev(SomeMsg) => ... // convenience when data not needed } when(Two, stateTimeout = 5 seconds) { ... } initialize }Within the partial function the following values are returned for effecting state transitions:
stayfor staying in the same statestay using Data(...)for staying in the same state, but with different datastay forMax 5.millisfor staying with a state timeout; can be combined withusinggoto(...)for changing into a different state; also supportsusingandforMaxstopfor terminating this FSM actorEach of the above also supports the method
replying(AnyRef)for sending a reply before changing state.While changing state, custom handlers may be invoked which are registered using
onTransition. This is meant to enable concentrating different concerns in different places; you may choose to usewhenfor describing the properties of a state, including of course initiating transitions, but you can describe the transitions usingonTransitionto avoid having to duplicate that code among multiple paths which lead to a transition:onTransition { case Active -> _ => cancelTimer("activeTimer") }Multiple such blocks are supported and all of them will be called, not only the first matching one.
Another feature is that other actors may subscribe for transition events by sending a
SubscribeTransitionCallbackmessage to this actor; useUnsubscribeTransitionCallbackbefore stopping the other actor.State timeouts set an upper bound to the time which may pass before another message is received in the current state. If no external message is available, then upon expiry of the timeout a StateTimeout message is sent. Note that this message will only be received in the state for which the timeout was set and that any message received will cancel the timeout (possibly to be started again by the next transition).
Another feature is the ability to install and cancel single-shot as well as repeated timers which arrange for the sending of a user-specified message:
setTimer("tock", TockMsg, 1 second, true) // repeating setTimer("lifetime", TerminateMsg, 1 hour, false) // single-shot cancelTimer("tock") timerActive_? ("tock")