Added documentation to the Listener class

Author: pborissow

src/javaxt/express/notification/Listener.java

@@ -3,6 +3,19 @@
 
 public interface Listener {
 
+
+  //**************************************************************************
+  //** processEvent
+  //**************************************************************************
+  /** Used to process an event published by the NotificationService
+   *  @param event Type of event (e.g. "create", "update", "delete")
+   *  @param model Subject of the event (e.g. "User", "File", etc)
+   *  @param data Additional information related to the event (e.g. User ID)
+   *  @param timestamp Timestamp of when the event was published. Units are
+   *  in nanoseconds in UTC. Use the getMilliseconds() method in the
+   *  javaxt.express.utils.DateUtils. to convert the nanoseconds to
+   *  milliseconds.
+   */
     public void processEvent(String event, String model, Value data, long timestamp);
 
 }