/* * Copyright (c) 2015 Cisco Systems, Inc. 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 */ package org.opendaylight.mdsal.dom.api; import java.util.Collection; import java.util.EventListener; import org.eclipse.jdt.annotation.NonNull; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate; /** * Interface implemented by classes interested in receiving notifications about data tree changes. It provides * a cursor-based view of the change. */ public interface DOMDataTreeChangeListener extends EventListener { /** * Invoked when there was data change for the supplied path, which was used to register this listener. * *
* This method may be also invoked during registration of the listener if there is any pre-existing data * in the conceptual data tree for supplied path. This initial event will contain all pre-existing data as created. * *
* Note: If there is no pre-existing data, the method {@link #onInitialData} will be invoked. * *
* A data change event may be triggered spuriously, e.g. such that data before and after compare as equal.
* Implementations of this interface are expected to recover from such events. Event producers are expected to exert
* reasonable effort to suppress such events. In other words, it is completely acceptable to observe
* a {@link org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode}, which reports
* a {@link org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType} other than UNMODIFIED, while
* the before- and after- data items compare as equal.
*
* @param changes Collection of change events, may not be null or empty.
* @throws NullPointerException if {@code changes} is null
*/
void onDataTreeChanged(@NonNull Collection
* Default implementation does nothing and is appropriate for users who do not care about ascertaining
* initial stat.
*/
default void onInitialData() {
//no-op
}
}