Add onEventTracked listener (#56)

Author: elliotykim

core-api/src/main/java/com/optimizely/ab/Optimizely.java

@@ -256,6 +256,9 @@ private void track(@Nonnull String eventName,
         } catch (Exception e) {
             logger.error("Unexpected exception in event dispatcher", e);
         }
+
+        notificationBroadcaster.broadcastEventTracked(eventName, userId, attributes, eventValue,
+                conversionEvent);
     }
 
     //======== live variable getters ========//

core-api/src/main/java/com/optimizely/ab/notification/NotificationBroadcaster.java

@@ -18,13 +18,15 @@
 import com.optimizely.ab.annotations.VisibleForTesting;
 import com.optimizely.ab.config.Experiment;
 import com.optimizely.ab.config.Variation;
+import com.optimizely.ab.event.LogEvent;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.HashSet;
 import java.util.Map;
 
+import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
@@ -75,6 +77,25 @@ public void clearListeners() {
         logger.debug("Notification listeners were cleared");
     }
 
+    /**
+     * Notify listeners that an Optimizely event has been tracked.
+     *
+     * @param eventKey the key of the tracked event
+     * @param userId the ID of the user
+     * @param attributes a map of attributes about the event
+     * @param eventValue an integer to be aggregated for the event
+     * @param logEvent the log event sent to the event dispatcher
+     */
+    public void broadcastEventTracked(@Nonnull String eventKey,
+                                      @Nonnull String userId,
+                                      @Nonnull Map<String, String> attributes,
+                                      @CheckForNull Long eventValue,
+                                      @Nonnull LogEvent logEvent) {
+        for (final NotificationListener iterListener : listeners) {
+            iterListener.onEventTracked(eventKey, userId, attributes, eventValue, logEvent);
+        }
+    }
+
     /**
      * Notify listeners that an Optimizely experiment has been activated.
      *

core-api/src/main/java/com/optimizely/ab/notification/NotificationListener.java

@@ -17,9 +17,11 @@
 
 import com.optimizely.ab.config.Experiment;
 import com.optimizely.ab.config.Variation;
+import com.optimizely.ab.event.LogEvent;
 
 import java.util.Map;
 
+import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
@@ -33,6 +35,22 @@
  */
 public abstract class NotificationListener {
 
+    /**
+     * Listener that is called after an event is tracked.
+     *
+     * @param eventKey the key of the tracked event
+     * @param userId the ID of the user
+     * @param attributes a map of attributes about the event
+     * @param eventValue an integer to be aggregated for the event
+     * @param logEvent the log event sent to the event dispatcher
+     */
+    public void onEventTracked(@Nonnull String eventKey,
+                               @Nonnull String userId,
+                               @Nonnull Map<String, String> attributes,
+                               @CheckForNull Long eventValue,
+                               @Nonnull LogEvent logEvent) {
+    }
+
     /**
      * Listener that is called after an experiment has been activated.
      *

core-api/src/test/java/com/optimizely/ab/OptimizelyTestV3.java

@@ -1506,6 +1506,19 @@ public void addNotificationListener() throws Exception {
         optimizely.getVariableString("string_variable", userId, attributes, activateExperiment);
         verify(listener, times(2))
                 .onExperimentActivated(activatedExperiment, userId, attributes, actualVariation);
+
+        // Check if listener is notified after an event is tracked
+        EventType eventType = projectConfig.getEventTypes().get(0);
+        String eventKey = eventType.getKey();
+
+        when(mockEventBuilder.createConversionEvent(eq(projectConfig), eq(mockBucketer), eq(userId),
+                eq(eventType.getId()), eq(eventKey),
+                anyMapOf(String.class, String.class)))
+                .thenReturn(logEventToDispatch);
+
+        optimizely.track(eventKey, userId, attributes);
+        verify(listener, times(1))
+                .onEventTracked(eventKey, userId, attributes, null, logEventToDispatch);
     }
 
     /**
@@ -1560,6 +1573,19 @@ public void removeNotificationListener() throws Exception {
         optimizely.getVariableString("string_variable", userId, attributes, activateExperiment);
         verify(listener, never())
                 .onExperimentActivated(activatedExperiment, userId, attributes, actualVariation);
+
+        // Check if listener is notified after an event is tracked
+        EventType eventType = projectConfig.getEventTypes().get(0);
+        String eventKey = eventType.getKey();
+
+        when(mockEventBuilder.createConversionEvent(eq(projectConfig), eq(mockBucketer), eq(userId),
+                eq(eventType.getId()), eq(eventKey),
+                anyMapOf(String.class, String.class)))
+                .thenReturn(logEventToDispatch);
+
+        optimizely.track(eventKey, userId, attributes);
+        verify(listener, never())
+                .onEventTracked(eventKey, userId, attributes, null, logEventToDispatch);
     }
 
     /**
@@ -1613,6 +1639,19 @@ public void clearNotificationListeners() throws Exception {
         optimizely.getVariableString("string_variable", userId, attributes, activateExperiment);
         verify(listener, never())
                 .onExperimentActivated(activatedExperiment, userId, attributes, actualVariation);
+
+        // Check if listener is notified after a event is tracked
+        EventType eventType = projectConfig.getEventTypes().get(0);
+        String eventKey = eventType.getKey();
+
+        when(mockEventBuilder.createConversionEvent(eq(projectConfig), eq(mockBucketer), eq(userId),
+                eq(eventType.getId()), eq(eventKey),
+                anyMapOf(String.class, String.class)))
+                .thenReturn(logEventToDispatch);
+
+        optimizely.track(eventKey, userId, attributes);
+        verify(listener, never())
+                .onEventTracked(eventKey, userId, attributes, null, logEventToDispatch);
     }
 
     //======== Helper methods ========//

core-api/src/test/java/com/optimizely/ab/notification/NotificationBroadcasterTest.java

@@ -17,6 +17,7 @@
 
 import com.optimizely.ab.config.Experiment;
 import com.optimizely.ab.config.Variation;
+import com.optimizely.ab.event.LogEvent;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -103,6 +104,26 @@ public void clearListeners() throws Exception {
                 0, notificationBroadcaster.listeners.size());
     }
 
+    /**
+     * Verify that {@link NotificationBroadcaster#broadcastEventTracked(String, String, Map, Long, LogEvent)}
+     * notifies all listeners.
+     */
+    @Test
+    public void broadcastEventTracked() throws Exception {
+        notificationBroadcaster.addListener(listener);
+        notificationBroadcaster.addListener(listener2);
+
+        String eventKey = "event1";
+        String userId = "user1";
+        Map<String, String> attributes = Collections.emptyMap();
+        Long eventValue = 0L;
+        LogEvent logEvent = mock(LogEvent.class);
+        notificationBroadcaster.broadcastEventTracked(
+                eventKey, userId, attributes, eventValue, logEvent);
+        verify(listener).onEventTracked(eventKey, userId, attributes, eventValue, logEvent);
+        verify(listener2).onEventTracked(eventKey, userId, attributes, eventValue, logEvent);
+    }
+
     /**
      * Verify that {@link NotificationBroadcaster#broadcastExperimentActivated(Experiment, String, Map, Variation)}
      * notifies all listeners.