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Java > Open Source Codes > org > apache > cayenne > graph > GraphDiff


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19
20 package org.apache.cayenne.graph;
21
22 import java.io.Serializable JavaDoc;
23
24 /**
25  * Represents a change in an object graph. This can be a simple change (like a node
26  * property update) or a composite change that consists of a number of smaller changes.
27  *
28  * @since 1.2
29  * @author Andrus Adamchik
30  */
31 public interface GraphDiff extends Serializable JavaDoc {
32
33     /**
34      * Returns true if this diff is simply a placeholder and does not perform any actual
35      * operation.
36      */
37     boolean isNoop();
38
39     /**
40      * Calls appropriate methods on the handler to "replay" this change.
41      */
42     void apply(GraphChangeHandler handler);
43
44     /**
45      * Calls appropriate methods on the handler to revert this change.
46      */
47     void undo(GraphChangeHandler handler);
48 }
49
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