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Java > Open Source Codes > com > caucho > widget > impl > UrlVarHolder


1 /*
2  * Copyright (c) 1998-2005 Caucho Technology -- all rights reserved
3  *
4  * This file is part of Resin(R) Open Source
5  *
6  * Each copy or derived work must preserve the copyright notice and this
7  * notice unmodified.
8  *
9  * Resin Open Source is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Resin Open Source is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17  * of NON-INFRINGEMENT. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with Resin Open Source; if not, write to the
22  * Free SoftwareFoundation, Inc.
23  * 59 Temple Place, Suite 330
24  * Boston, MA 02111-1307 USA
25  *
26  * @author Sam
27  */
28
29 package com.caucho.widget.impl;
30
31 import com.caucho.util.L10N;
32
33 public class UrlVarHolder
34   extends VarHolder
35 {
36   private static final L10N L = new L10N(UrlVarHolder.class);
37
38   private static final Object NULL_VALUE = new Object();
39
40   private VarHolder _varHolder;
41
42   /**
43    * The underlying VarHolder, values in this VarHolder override.
44    *
45    * @param varHolder
46    */
47   public void setVarHolder(VarHolder varHolder)
48   {
49     _varHolder = varHolder;
50     super.setWidgetInit(_varHolder.getWidgetInit());
51   }
52
53   public void init()
54   {
55     super.init();
56
57     if (_varHolder == null)
58       throw new IllegalStateException(L.l("`{0}' is required", "var-holder"));
59   }
60
61   public void destroy()
62   {
63     _varHolder = null;
64
65     super.destroy();
66   }
67
68   protected Object getVarImpl(String name,
69                               boolean isDefaultValue,
70                               Object defaultValue)
71   {
72     Object value = super.getVarImpl(name, true, NULL_VALUE);
73
74     if (value == NULL_VALUE)
75        value = _varHolder.getVarImpl(name, isDefaultValue, defaultValue);
76
77     return value;
78   }
79 }
80
81
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