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


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:if tag.
39  */
40 public class JstlCoreIf extends JstlNode {
41   private static final QName TEST = new QName("test");
42   private static final QName VAR = new QName("var");
43   private static final QName SCOPE = new QName("scope");
44   
45   private String JavaDoc _test;
46   private String JavaDoc _var;
47   private String JavaDoc _scope;
48   
49   private JspAttribute _testAttr;
50   
51   /**
52    * Adds an attribute.
53    */
54   public void addAttribute(QName name, String JavaDoc value)
55     throws JspParseException
56   {
57     if (TEST.equals(name))
58       _test = value;
59     else if (VAR.equals(name))
60       _var = value;
61     else if (SCOPE.equals(name))
62       _scope = value;
63     else
64       throw error(L.l("`{0}' is an unknown attribute for <{1}>.",
65                       name.getName(), getTagName()));
66   }
67   
68   /**
69    * Adds an attribute.
70    */
71   public void addAttribute(QName name, JspAttribute value)
72     throws JspParseException
73   {
74     if (TEST.equals(name))
75       _testAttr = value;
76     else
77       throw error(L.l("`{0}' is an unknown jsp:attribute for <{1}>.",
78                       name.getName(), getTagName()));
79   }
80
81   /**
82    * Returns true if the tag has scripting values.
83    */
84   public boolean hasScripting()
85   {
86     return (super.hasScripting() ||
87         hasScripting(_test) || hasScripting(_testAttr));
88   }
89
90   /**
91    * Generates the XML text representation for the tag validation.
92    *
93    * @param os write stream to the generated XML.
94    */
95   public void printXml(WriteStream os)
96     throws IOException JavaDoc
97   {
98     os.print("<c:if test=\"");
99     if (_testAttr != null)
100       _testAttr.printXml(os);
101     else
102       printXmlText(os, _test);
103     os.print("\">");
104
105     printXmlChildren(os);
106
107     os.print("</c:if>");
108   }
109   
110   /**
111    * Generates the code for the c:if tag.
112    */
113   public void generate(JspJavaWriter out)
114     throws Exception JavaDoc
115   {
116     if (_test == null && _testAttr == null)
117       throw error(L.l("required attribute `test' missing from <{0}>",
118                       getTagName()));
119
120     String JavaDoc ifExpr;
121
122     if (_testAttr != null)
123       ifExpr = _testAttr.generateValue(boolean.class);
124     else
125       ifExpr = generateValue(boolean.class, _test);
126
127     out.println("if (" + ifExpr + ") {");
128     out.pushDepth();
129
130     if (_var != null)
131       generateSetNotNull(out, _var, _scope, "Boolean.TRUE");
132     
133     generateChildren(out);
134     
135     out.popDepth();
136     out.println("}");
137
138     if (_var != null) {
139       out.println("else {");
140       out.pushDepth();
141       
142       generateSetNotNull(out, _var, _scope, "Boolean.FALSE");
143       
144       out.popDepth();
145       out.println("}");
146     }
147   }
148 }
149
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