Hi @LyonMartin ,
This is a common issue when working with AEM EventHandlers and listening to Page Events via PageEvent.EVENT_TOPIC. Here’s a breakdown of why your handleEvent() may not be triggered and how to fix it.
Root Causes & Solutions
1. PageEvent.EVENT_TOPIC Might Not Be Triggered as Expected
You're listening to:
"event.topics=" + PageEvent.EVENT_TOPIC
which resolves to:
com/day/cq/wcm/core/page
However, AEM doesn’t always trigger this topic for all page modifications/creations. It’s often used for specific programmatic page events, not low-level JCR events.
What You Can Check or Do:
A. Ensure Event Admin is Working
Confirm in /system/console/bundles that Apache Sling Event and EventAdmin bundles are active.
Check logs (error.log) for any activation issues with your handler.
B. Add Logging in handleEvent() for Confirmation
Add logs to see if it’s triggered at all:
@Override
public void handleEvent(Event event) {
System.out.println("Event received: " + event.getTopic());
}
C. Alternative Approach: Use Sling Resource Events
Try listening to Sling resource-level events which are more reliable for content changes.
@Component(service = EventHandler.class, immediate = true, property = {
EventConstants.EVENT_TOPIC + "=org/apache/sling/api/resource/Resource/ADDED",
EventConstants.EVENT_TOPIC + "=org/apache/sling/api/resource/Resource/CHANGED"
})
public class ResourceEventHandler implements EventHandler {
@Override
public void handleEvent(Event event) {
System.out.println("Resource Event: " + event.getTopic());
}
}
D. Preferred Solution: Use ResourceChangeListener
Adobe recommends this modern approach:
@Component(service = ResourceChangeListener.class, immediate = true, property = {
ResourceChangeListener.PATHS + "=/content",
ResourceChangeListener.CHANGES + "=ADDED",
ResourceChangeListener.CHANGES + "=CHANGED",
ResourceChangeListener.CHANGES + "=REMOVED"
})
public class PageChangeListener implements ResourceChangeListener {
@Override
public void onChange(List<ResourceChange> changes) {
for (ResourceChange change : changes) {
System.out.println("Change detected: " + change.getPath());
}
}
}
Regards,
Amit Vishwakarma
