# Notifications and Event Handling

Author: Eike Stepper

This chapter describes how to handle notifications and events in CDO client applications. Notifications are essential for building responsive applications that react to changes in the repository, whether triggered locally or remotely.

CDO provides APIs for listening to model changes, handling remote updates, and implementing custom event processing logic. Understanding these mechanisms enables you to synchronize application state, update user interfaces, and coordinate collaborative workflows.

## 1 Listening for Model Changes

CDO emits notifications when model objects are created, modified, or deleted. This section explains how to register listeners, process change events, and update your application in response to model changes. Learn best practices for efficient event handling and minimizing performance impact.

## 2 Handling Remote Updates

Remote updates occur when changes are made to the repository by other clients or processes. This section covers how to detect and respond to remote updates, synchronize local state, and resolve conflicts that may arise from concurrent modifications.

## 3 Custom Event Processing

Extend CDO's event handling capabilities with custom logic. Learn how to implement custom event processors, filter events, and integrate notifications with external systems or workflows.

Copyright (c) 2004-2025 Eike Stepper (Loehne, Germany) and others.
All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html