org.onehippo.cms7.services.eventbus

Interface HippoEventBus

public interface HippoEventBus

Generic Hippo event bus. Specific implementations can dispatch events based on metadata of the listener and event objects. (see e.g. the guava implementation)

Listeners can be registered using the whiteboard pattern. Methods in the listener class hierarchy, annotated with the Subscribe annotation will be invoked when events of a suitable type are dispatched. (see the Subscribe documentation for details) Example :

 
 //
 MyObject() {
     ... initialization

     // register as a listener using the whiteboard pattern
     HippoServiceRegistry.registerService(this, HippoEventBus.class);
 }

 // implement a HippoEvent receiver method and annotate it with 'Subscribe'
 // Note that the method with the annotation MUST be public
 @Subscribe
 public void processHippoEvent(HippoEvent<?> event) {
     System.out.println(event);
 }
 
 

If you are only interested in HippoEvents, you can implement the HippoEventListener instead. Then, you also don't need to annotate the onEvent. For example:

 
 // get the eventBus
 HippoServiceRegistry.registerService(new HippoEventListener() {
     // implement the onEvent method
     // Note that the method with the annotation MUST be public
     public void onEvent(HippoEvent<?> event) {
         System.out.println(event);
     }
 }, HippoEventBus.class);
 

Method Summary

Modifier and Type	Method and Description
void	post(Object event) Publish an event to registered listeners.
void	register(Object listener) Deprecated.
void	unregister(Object listener) Deprecated. use the whiteboard pattern instead

Method Detail

register

@Deprecated
void register(Object listener)

Deprecated.

Parameters:

listener -

unregister

@Deprecated
void unregister(Object listener)

Deprecated. use the whiteboard pattern instead

Unregister the listener.

Parameters:

listener -

post

void post(Object event)

Publish an event to registered listeners. Their annotated methods (with suitable parameter types) will be invoked.

Parameters:

event -