Package com.atlassian.event.api

Interface EventPublisher

All Superinterfaces:
EventListenerRegistrar
All Known Implementing Classes:
EventPublisherImpl
public interface EventPublisher extends EventListenerRegistrar
Interface to publish events. It allows the decoupling of listeners which handle events and publishers which dispatch events.
Since:
2.0
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    publish(Object event)
    Publish an event that will be consumed by all listeners which have registered to receive it.

    Methods inherited from interface com.atlassian.event.api.EventListenerRegistrar

    register, unregister, unregisterAll

  • Method Details

    • publish

      void publish(@Nonnull Object event)
      Publish an event that will be consumed by all listeners which have registered to receive it. Implementations must dispatch events to listeners which have a public method annotated with EventListener and one argument which is assignable from the event type (i.e. a superclass or interface implemented by the event object). This method should process all event listeners, despite any errors or exceptions that are generated as a result of dispatching the event.

      Default order

      The order in which registered listeners are invoked is predictable. Listeners will be invoked for listeners registered on the object itself, then listeners on the parent class, then the grandparent and so on until finally all listeners for java.lang.Object are invoked.

      After walking the class hierarchy the interface listeners are invoked, again from the most specific interface first. Note that the ordering within a specific event type is not guaranteed. If there are multiple registered listeners for IssueEvent, then they will be invoked in the order of registration. It is however guaranteed that a listener for IssueEvent will be invoked before a listener for Event

      Custom order

      The default order can be overridden with EventListener.order(). Event listeners with order defined are overriding default rules and will be processed in ascending order of the EventListener.order() value. Default ordering is preserved when processing event listeners with the same EventListener.order() value. There is a soft rule for plugin event listeners to use order values in range [-1000, 1000] if needed. Values in following ranges: [Integer.MIN_VALUE, -1000) and (1000, Integer.MAX_VALUE] are reserved for Atlassian product internal event listeners.
      Parameters:
      event - the event to publish
      Throws:
      NullPointerException - if the event is null