/*****************************************************************
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
****************************************************************/
package org.apache.cayenne.graph;
import java.io.Serializable;
/**
* Represents a change in an object graph. This can be a simple change (like a node
* property update) or a composite change that consists of a number of smaller changes.
*
* @since 1.2
*/
public interface GraphDiff extends Serializable {
/**
* Returns true if this diff is simply a placeholder and does not perform any actual
* operation.
*/
boolean isNoop();
/**
* Calls appropriate methods on the handler to "replay" this change.
*/
void apply(GraphChangeHandler handler);
/**
* Calls appropriate methods on the handler to revert this change.
*/
void undo(GraphChangeHandler handler);
}