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Java > Open Source Codes > com > caucho > jsp > java > JstlCoreRtWhen


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.jsp.java;
30
31 import com.caucho.jsp.JspParseException;
32 import com.caucho.vfs.WriteStream;
33 import com.caucho.xml.QName;
34
35 import java.io.IOException JavaDoc;
36
37 /**
38  * Special generator for a JSTL c:when tag.
39  */
40 public class JstlCoreRtWhen extends JstlNode {
41   private static final QName TEST = new QName("test");
42   private Object JavaDoc _test;
43   
44   /**
45    * Adds an attribute.
46    */
47   public void addAttribute(QName name, String JavaDoc value)
48     throws JspParseException
49   {
50     if (TEST.equals(name))
51       _test = value;
52     else
53       throw error(L.l("`{0}' is an unknown attribute for <{1}>.",
54                       name.getName(), getTagName()));
55   }
56   
57   /**
58    * Adds a fragment attribute.
59    */
60   public void addAttribute(String JavaDoc name, JspAttribute value)
61     throws JspParseException
62   {
63     if (name.equals("test"))
64       _test = value;
65     else
66       throw error(L.l("`{0}' can is an illegal jsp:attribute for <{1}>.",
67                       name, getTagName()));
68   }
69
70   /**
71    * Generates the XML text representation for the tag validation.
72    *
73    * @param os write stream to the generated XML.
74    */
75   public void printXml(WriteStream os)
76     throws IOException JavaDoc
77   {
78     os.print("<c-rt:when");
79
80     if (_test instanceof String JavaDoc) {
81       os.print(" test=\"");
82       printXmlText(os, (String JavaDoc) _test);
83       os.print("\">");
84     }
85     else {
86       os.print(">");
87     }
88
89     printXmlChildren(os);
90
91     os.print("</c-rt:when>");
92   }
93   
94   /**
95    * Generates the code for the c:if tag.
96    */
97   public void generate(JspJavaWriter out)
98     throws Exception JavaDoc
99   {
100     if (_test == null)
101       throw error(L.l("required attribute `test' missing from <{0}>",
102                       getTagName()));
103
104     String JavaDoc ifExpr = generateRTValue(boolean.class, _test);
105
106     out.println("if (" + ifExpr + ") {");
107     out.pushDepth();
108     generateChildren(out);
109
110     out.popDepth();
111     out.println("}");
112   }
113 }
114
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