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1 /*
2 * $Id: StateHolder.java,v 1.17 2007/04/27 22:00:03 ofung Exp $
3 */
4
5 /*
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
7 *
8 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
9 *
10 * The contents of this file are subject to the terms of either the GNU
11 * General Public License Version 2 only ("GPL") or the Common Development
12 * and Distribution License("CDDL") (collectively, the "License"). You
13 * may not use this file except in compliance with the License. You can obtain
14 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
15 * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
16 * language governing permissions and limitations under the License.
17 *
18 * When distributing the software, include this License Header Notice in each
19 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
20 * Sun designates this particular file as subject to the "Classpath" exception
21 * as provided by Sun in the GPL Version 2 section of the License file that
22 * accompanied this code. If applicable, add the following below the License
23 * Header, with the fields enclosed by brackets [] replaced by your own
24 * identifying information: "Portions Copyrighted [year]
25 * [name of copyright owner]"
26 *
27 * Contributor(s):
28 *
29 * If you wish your version of this file to be governed by only the CDDL or
30 * only the GPL Version 2, indicate your decision by adding "[Contributor]
31 * elects to include this software in this distribution under the [CDDL or GPL
32 * Version 2] license." If you don't indicate a single choice of license, a
33 * recipient has the option to distribute your version of this file under
34 * either the CDDL, the GPL Version 2 or to extend the choice of license to
35 * its licensees as provided above. However, if you add GPL Version 2 code
36 * and therefore, elected the GPL Version 2 license, then the option applies
37 * only if the new code is made subject to such option by the copyright
38 * holder.
39 */
40
41 package javax.faces.component;
42
43 import javax.faces.context.FacesContext;
44
45 /**
46 *
47 * <p>This interface is implemented by classes that need to save their
48 * state between requests.</p>
49 *
50 * <p>An implementor <strong>must</strong> implement both {@link
51 * #saveState} and {@link #restoreState} methods in this class, since
52 * these two methods have a tightly coupled contract between themselves.
53 * In other words, if there is an ineritance hierarchy, it is not
54 * permissable to have the {@link #saveState} and {@link #restoreState}
55 * methods reside at different levels of the hierarchy.</p>
56 *
57 * <p>An implementor must have a public no-args constructor.</p>
58 *
59 */
60
61 public interface StateHolder {
62
63 /**
64 * <p> Gets the state of the instance as a
65 * <code>Serializable</code> Object.<p>
66 *
67 * <p>If the class that implements this interface has references to
68 * instances that implement StateHolder (such as a
69 * <code>UIComponent</code> with event handlers, validators, etc.)
70 * this method must call the {@link #saveState} method on all those
71 * instances as well. <strong>This method must not save the state
72 * of children and facets.</strong> That is done via the {@link
73 * javax.faces.application.StateManager}</p>
74 *
75 * <p>This method must not alter the state of the implementing
76 * object. In other words, after executing this code:</p>
77 *
78 * <code><pre>
79 * Object state = component.saveState(facesContext);
80 * </pre></code>
81 *
82 * <p><code>component</code> should be the same as before executing
83 * it.</p>
84 *
85 * <p>The return from this method must be <code>Serializable</code></p>
86 *
87 * @throws NullPointerException if <code>context</code> is null
88 */
89
90 public Object saveState(FacesContext context);
91
92 /**
93 *
94 * <p> Perform any processing required to restore the state from the
95 * entries in the state Object.</p>
96 *
97 * <p>If the class that implements this interface has references to
98 * instances that also implement StateHolder (such as a
99 * <code>UIComponent</code> with event handlers, validators, etc.)
100 * this method must call the {@link #restoreState} method on all those
101 * instances as well. </p>
102 *
103 * @throws NullPointerException if either <code>context</code> or
104 * <code>state</code> are <code>null</code>
105 */
106
107 public void restoreState(FacesContext context, Object state);
108
109 /**
110 *
111 * <p>If true, the Object implementing this interface must not
112 * participate in state saving or restoring.</p>
113 */
114
115 public boolean isTransient();
116
117 /**
118 * <p>Denotes whether or not the Object implementing this interface must
119 * or must not participate in state saving or restoring.</p>
120 *
121 * @param newTransientValue boolean pass <code>true</code> if this Object
122 * will participate in state saving or restoring, otherwise
123 * pass <code>false</code>.
124 */
125 public void setTransient(boolean newTransientValue);
126
127 }