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.controller.md.sal.binding.api;
10 import org.eclipse.jdt.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
18 public interface DataTreeChangeService extends BindingService {
20 * Registers a {@link DataTreeChangeListener} to receive
21 * notifications when data changes under a given path in the conceptual data
25 * You are able to register for notifications for any node or subtree
26 * which can be represented using {@link DataTreeIdentifier}.
29 * You are able to register for data change notifications for a subtree or leaf
30 * even if it does not exist. You will receive notification once that node is
34 * If there is any pre-existing data in the data tree for the path for which you are
35 * registering, you will receive an initial data change event, which will
36 * contain all pre-existing data, marked as created.
39 * This method returns a {@link ListenerRegistration} object. To
40 * "unregister" your listener for changes call the {@link ListenerRegistration#close()}
41 * method on the returned object.
44 * You MUST explicitly unregister your listener when you no longer want to receive
45 * notifications. This is especially true in OSGi environments, where failure to
46 * do so during bundle shutdown can lead to stale listeners being still registered.
49 * Data tree identifier of the subtree which should be watched for
52 * Listener instance which is being registered
53 * @return Listener registration object, which may be used to unregister
54 * your listener using {@link ListenerRegistration#close()} to stop
55 * delivery of change events.
57 <T extends DataObject, L extends DataTreeChangeListener<T>> @NonNull ListenerRegistration<L>
58 registerDataTreeChangeListener(@NonNull DataTreeIdentifier<T> treeId, @NonNull L listener);