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Java > Open Source Codes > com > caucho > jstl > el > WhenTag


1 /*
2  * Copyright (c) 1998-2006 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 Scott Ferguson
27  */
28
29 package com.caucho.jstl.el;
30
31 import com.caucho.el.Expr;
32 import com.caucho.jsp.PageContextImpl;
33 import com.caucho.jstl.ChooseTag;
34 import com.caucho.util.L10N;
35
36 import javax.el.ELException;
37 import javax.servlet.jsp.JspException JavaDoc;
38 import javax.servlet.jsp.tagext.Tag JavaDoc;
39 import javax.servlet.jsp.tagext.TagSupport JavaDoc;
40
41 /**
42  * Tag representing an "when" condition.
43  */
44 public class WhenTag extends TagSupport JavaDoc {
45   private static L10N L = new L10N(WhenTag.class);
46   
47   private Expr _testExpr;
48
49   /**
50    * Sets the test expression.
51    *
52    * @param test the test expression.
53    */
54   public void setTest(Expr test)
55   {
56     _testExpr = test;
57   }
58
59   /**
60    * Process the tag.
61    */
62   public int doStartTag()
63     throws JspException JavaDoc
64   {
65     try {
66       Tag parent = getParent();
67
68       if (! (parent instanceof ChooseTag))
69     throw new JspException JavaDoc(L.l("c:when tag must be contained in a c:choose tag."));
70
71       ChooseTag chooseTag = (ChooseTag) parent;
72
73       if (chooseTag.isMatch())
74     return SKIP_BODY;
75
76       PageContextImpl pageContext = (PageContextImpl) this.pageContext;
77       boolean test = _testExpr.evalBoolean(pageContext.getELContext());
78
79       if (test) {
80     chooseTag.setMatch();
81       
82     return EVAL_BODY_INCLUDE;
83       }
84       else
85     return SKIP_BODY;
86     } catch (ELException e) {
87       throw new JspException JavaDoc(e);
88     }
89   }
90 }
91
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