KickJava   Java API By Example, From Geeks To Geeks.

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


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