org.xwiki.observation
Interface ObservationManager

@ComponentRole
public interface ObservationManager

The main orchestrator for event notification. To receive events create a component implementing the EventListener interface. Your component will be automatically registered when this Observation Manager component is loaded. To send events to all registered listeners, call one of the notify(org.xwiki.observation.event.Event, java.lang.Object, java.lang.Object) methods.

Version:

$Id$

Method Summary

void	addEvent(String listenerName, Event event) Adds an Event to an already registered listener.
void	addListener(EventListener eventListener) Manually add a listener.
EventListener	getListener(String listenerName)
void	notify(Event event, Object source) Convenience front-end where the additional data parameter is null.
void	notify(Event event, Object source, Object data) Call the registered listeners matching the passed Event.
void	removeEvent(String listenerName, Event event) Removes an Event to an already registered listener.
void	removeListener(String listenerName) Remove a listener from the list of registered listeners.

Method Detail

addListener

void addListener(EventListener eventListener)

Manually add a listener. Components implementing the EventListener interfaces are only loaded when the Observation Manager component is created. Thus if you need to add a new listener while the system is running you'll need to call this method. Also note that contrary to other components it's not possible for the Observation Manager to watch Component Manager events since the Component Manager is itself using the Observation Manager to send its events (chicken and egg problem). Thus if any new Event Listener is created dynamically it needs to be added using this method manually.

Parameters:

eventListener - the listener to register

removeListener

void removeListener(String listenerName)

Remove a listener from the list of registered listeners. The removed listener will no longer receive events.

Parameters:

listenerName - the name of the listener to remove (must match EventListener.getName()

addEvent

void addEvent(String listenerName,
              Event event)

Adds an Event to an already registered listener.

Parameters:

listenerName - the name of the listener to which the event must be added (must match EventListener.getName()

event - the event to add to the matching listener

removeEvent

void removeEvent(String listenerName,
                 Event event)

Removes an Event to an already registered listener.

Parameters:

listenerName - the name of the listener to which the event must be removed (must match EventListener.getName()

event - the event to remove to the matching listener

getListener

EventListener getListener(String listenerName)

Parameters:

listenerName - the name of the listener

Returns:

the registered listener's instance or null if no listener is registered under that name

notify

void notify(Event event,
            Object source,
            Object data)

Call the registered listeners matching the passed Event. The definition of source and data is purely up to the communicating classes.

Parameters:

event - the event to pass to the registered listeners

source - the source of the event (or null)

data - the additional data related to the event (or null)

notify

void notify(Event event,
            Object source)

Convenience front-end where the additional data parameter is null.

Parameters:

event - the event to pass to the registered listeners

source - the source of the event (or null)

See Also:

notify(org.xwiki.observation.event.Event, Object, Object)