KickJava   Java API By Example, From Geeks To Geeks.

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


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.jsp.PageContextImpl;
32 import com.caucho.util.L10N;
33 import com.caucho.xpath.Env;
34 import com.caucho.xpath.XPath;
35 import com.caucho.xpath.XPathException;
36
37 import org.w3c.dom.Node JavaDoc;
38
39 import javax.servlet.jsp.JspException JavaDoc;
40 import javax.servlet.jsp.tagext.TagSupport JavaDoc;
41
42 /**
43  * Tag representing an "if" condition.
44  */
45 public class XmlIfTag extends TagSupport JavaDoc {
46   private static L10N L = new L10N(XmlIfTag.class);
47   
48   private com.caucho.xpath.Expr _select;
49
50   private String JavaDoc _var;
51   private String JavaDoc _scope;
52
53   /**
54    * Sets the JSP-EL expression value.
55    */
56   public void setSelect(com.caucho.xpath.Expr select)
57   {
58     _select = select;
59   }
60
61   /**
62    * Sets the variable which should contain the result of the test.
63    */
64   public void setVar(String JavaDoc var)
65   {
66     _var = var;
67   }
68
69   /**
70    * Sets the scope for the variable.
71    */
72   public void setScope(String JavaDoc scope)
73   {
74     _scope = scope;
75   }
76
77   /**
78    * Process the tag.
79    */
80   public int doStartTag()
81     throws JspException JavaDoc
82   {
83     try {
84       boolean test = evalBoolean((PageContextImpl) pageContext, _select);
85
86       Boolean JavaDoc value = test ? Boolean.TRUE : Boolean.FALSE;
87
88       if (_var == null) {
89       }
90       else
91         CoreSetTag.setValue(pageContext, _var, _scope, value);
92
93       return test ? EVAL_BODY_INCLUDE : SKIP_BODY;
94     } catch (Exception JavaDoc e) {
95       throw new JspException JavaDoc(e);
96     }
97   }
98
99   /**
100    * Evaluates as a boolean.
101    */
102   public static boolean evalBoolean(PageContextImpl pageContext,
103                     com.caucho.xpath.Expr select)
104     throws XPathException
105   {
106     Env env = XPath.createEnv();
107     env.setVarEnv(((PageContextImpl) pageContext).getVarEnv());
108       
109     Node JavaDoc node = pageContext.getNodeEnv();
110       
111     boolean test = select.evalBoolean(node, env);
112
113     env.free();
114
115     return test;
116   }
117 }
118
Popular Tags