net.liftweb.http

ListenerManager

trait ListenerManager extends AnyRef

This trait manages a set of Actors in a publish/subscribe pattern. When you extend your Actor with this trait, you automatically get handling for sending messages out to all subscribed Actors. Simply override the high-, medium-, or lowPriority handlers to do your message processing. When you want to update all subscribers, just call the updateListeners method. The createUpdate method is used to generate the message that you want sent to all subscribers.

Note that the AddAListener and RemoveAListener messages (for subscription control) are processed after any highPriority or mediumPriority messages are processed, so take care to avoid overly broad matches in those handlers that might consume internal messages.

For example, you could write a simple service to provide clock ticks using the following code:

case object Tick

object Ticker extends ListenerManager { import net.liftweb.util.ActorPing

// Set up the initial tick ActorPing.schedule(this, Tick, 1000L)

// This is a placeholder, since we're only interested // in Ticks def createUpdate = "Registered"

override def mediumPriority = { case Tick => { updateListeneres(Tick) ActorPing.schedule(this, Tick, 1000L) } } }

A client CometActor could look like:

class CometClock extends CometListener {
  val registerWith = Ticker

... handling code ... }

go to: companion
linear super types: AnyRef, Any
known subclasses: LiftActorJWithListenerManager
self type: ListenerManager with SimpleActor[Any]
    see also:
  1. CometListener

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Value Members

  1. def != (arg0: AnyRef) : Boolean

    attributes: final
    definition classes: AnyRef
  2. def != (arg0: Any) : Boolean

    o != arg0 is the same as !(o == (arg0)).

    o != arg0 is the same as !(o == (arg0)).

    arg0

    the object to compare against this object for dis-equality.

    returns

    false if the receiver object is equivalent to the argument; true otherwise.

    attributes: final
    definition classes: Any
  3. def ## () : Int

    attributes: final
    definition classes: AnyRef → Any
  4. def $asInstanceOf [T0] () : T0

    attributes: final
    definition classes: AnyRef
  5. def $isInstanceOf [T0] () : Boolean

    attributes: final
    definition classes: AnyRef
  6. def == (arg0: AnyRef) : Boolean

    o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).

    o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    attributes: final
    definition classes: AnyRef
  7. def == (arg0: Any) : Boolean

    o == arg0 is the same as o.equals(arg0).

    o == arg0 is the same as o.equals(arg0).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    attributes: final
    definition classes: Any
  8. def asInstanceOf [T0] : T0

    This method is used to cast the receiver object to be of type T0.

    This method is used to cast the receiver object to be of type T0.

    Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expressionList(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested typed.

    returns

    the receiver object.

    attributes: final
    definition classes: Any
  9. def clone () : AnyRef

    This method creates and returns a copy of the receiver object.

    This method creates and returns a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

    attributes: protected
    definition classes: AnyRef
  10. def createUpdate : Any

    This method is called when the

    updateListeners()
    method needs a message to send to subscribed Actors.

    This method is called when the

    updateListeners()
    method needs a message to send to subscribed Actors. In particular, createUpdate is used to create the first message that a newly subscribed CometListener will receive.

    attributes: protected abstract
  11. def eq (arg0: AnyRef) : Boolean

    This method is used to test whether the argument (arg0) is a reference to the receiver object (this).

    This method is used to test whether the argument (arg0) is a reference to the receiver object (this).

    The eq method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on non-null instances of AnyRef: * It is reflexive: for any non-null instance x of type AnyRef, x.eq(x) returns true. * It is symmetric: for any non-null instances x and y of type AnyRef, x.eq(y) returns true if and only if y.eq(x) returns true. * It is transitive: for any non-null instances x, y, and z of type AnyRef if x.eq(y) returns true and y.eq(z) returns true, then x.eq(z) returns true.

    Additionally, the eq method has three other properties. * It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false. * For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false. * null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    arg0

    the object to compare against this object for reference equality.

    returns

    true if the argument is a reference to the receiver object; false otherwise.

    attributes: final
    definition classes: AnyRef
  12. def equals (arg0: Any) : Boolean

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation]: * It is reflexive: for any instance x of type Any, x.equals(x) should return true. * It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and only if y.equals(x) returns true. * It is transitive: for any instances x, y, and z of type AnyRef if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

    If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is often necessary to override hashCode to ensure that objects that are "equal" (o1.equals(o2) returns true) hash to the same scala.Int (o1.hashCode.equals(o2.hashCode)).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    definition classes: AnyRef → Any
  13. def finalize () : Unit

    This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.

    This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.

    The details of when and if the finalize method are invoked, as well as the interaction between finalizeand non-local returns and exceptions, are all platform dependent.

    attributes: protected
    definition classes: AnyRef
  14. def getClass () : java.lang.Class[_]

    Returns a representation that corresponds to the dynamic class of the receiver object.

    Returns a representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    attributes: final
    definition classes: AnyRef
  15. def hashCode () : Int

    Returns a hash code value for the object.

    Returns a hash code value for the object.

    The default hashing algorithm is platform dependent.

    Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.

    returns

    the hash code value for the object.

    definition classes: AnyRef → Any
  16. def highPriority : PartialFunction[Any, Unit]

    Override this method to process high priority messages.

    Override this method to process high priority messages. Note:you must not process messages with a wildcard (match all), since this will intercept the messages used for subscription control.

    attributes: protected
  17. def isInstanceOf [T0] : Boolean

    This method is used to test whether the dynamic type of the receiver object is T0.

    This method is used to test whether the dynamic type of the receiver object is T0.

    Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested typed.

    returns

    true if the receiver object is an instance of erasure of type T0; false otherwise.

    attributes: final
    definition classes: Any
  18. def listenerService : PartialFunction[Any, Unit]

    attributes: protected
  19. def lowPriority : PartialFunction[Any, Unit]

    Override this method to process low priority messages.

    Override this method to process low priority messages.

    attributes: protected
  20. def mediumPriority : PartialFunction[Any, Unit]

    Override this method to process medium priority messages.

    Override this method to process medium priority messages. See the highPriority method for an important note on wildcard processing.

    attributes: protected
      see also:
    1. #highPriority

  21. def messageHandler : PartialFunction[Any, Unit]

    attributes: protected
  22. def ne (arg0: AnyRef) : Boolean

    o.ne(arg0) is the same as !(o.eq(arg0)).

    o.ne(arg0) is the same as !(o.eq(arg0)).

    arg0

    the object to compare against this object for reference dis-equality.

    returns

    false if the argument is not a reference to the receiver object; true otherwise.

    attributes: final
    definition classes: AnyRef
  23. def notify () : Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    attributes: final
    definition classes: AnyRef
  24. def notifyAll () : Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    attributes: final
    definition classes: AnyRef
  25. def synchronized [T0] (arg0: T0) : T0

    attributes: final
    definition classes: AnyRef
  26. def toString () : String

    Returns a string representation of the object.

    Returns a string representation of the object.

    The default representation is platform dependent.

    returns

    a string representation of the object.

    definition classes: AnyRef → Any
  27. def updateIfPassesTest (update: Any)(info: ()) : Unit

    This method provides legacy functionality for filtering messages before sending to each registered actor.

    This method provides legacy functionality for filtering messages before sending to each registered actor. It is deprecated in favor of doing the filtering in the registered Actor's message handling partial functions instead.

    attributes: protected
      deprecated:
    1. Accept/reject logic should be done in the partial function that handles the message.

  28. def updateListeners (msg: Any) : Unit

    Update the listeners with a message that we create.

    Update the listeners with a message that we create. Note that with this invocation the createUpdate method is not used.

    attributes: protected
  29. def updateListeners () : Unit

    Update the listeners with the message generated by createUpdate

    Update the listeners with the message generated by createUpdate

    attributes: protected
  30. def wait () : Unit

    attributes: final
    definition classes: AnyRef
  31. def wait (arg0: Long, arg1: Int) : Unit

    attributes: final
    definition classes: AnyRef
  32. def wait (arg0: Long) : Unit

    attributes: final
    definition classes: AnyRef

Inherited from AnyRef

Inherited from Any