2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.mdsal.binding.api;
10 import javax.annotation.Nonnull;
11 import org.opendaylight.yangtools.concepts.ListenerRegistration;
12 import org.opendaylight.yangtools.yang.binding.DataObject;
15 * A {@link BindingService} which allows users to register for changes to a subtree.
17 public interface DataTreeChangeService extends BindingService {
19 * Registers a {@link DataTreeChangeListener} to receive
20 * notifications when data changes under a given path in the conceptual data
23 * You are able to register for notifications for any node or subtree
24 * which can be represented using {@link DataTreeIdentifier}.
27 * You are able to register for data change notifications for a subtree or leaf
28 * even if it does not exist. You will receive notification once that node is
31 * If there is any pre-existing data in the data tree for the path for which you are
32 * registering, you will receive an initial data change event, which will
33 * contain all pre-existing data, marked as created.
36 * This method returns a {@link ListenerRegistration} object. To
37 * "unregister" your listener for changes call the {@link ListenerRegistration#close()}
38 * method on the returned object.
40 * You MUST explicitly unregister your listener when you no longer want to receive
41 * notifications. This is especially true in OSGi environments, where failure to
42 * do so during bundle shutdown can lead to stale listeners being still registered.
45 * Data tree identifier of the subtree which should be watched for
48 * Listener instance which is being registered
49 * @return Listener registration object, which may be used to unregister
50 * your listener using {@link ListenerRegistration#close()} to stop
51 * delivery of change events.
53 @Nonnull <T extends DataObject,L extends DataTreeChangeListener<T>> ListenerRegistration<L> registerDataTreeChangeListener(@Nonnull DataTreeIdentifier<T> treeId, @Nonnull L listener);