TrueTag


1   /**
2    * Copyright (C) 2001 Yasna.com. All rights reserved.
3    *
4    * ===================================================================
5    * The Apache Software License, Version 1.1
6    *
7    * Redistribution and use in source and binary forms, with or without
8    * modification, are permitted provided that the following conditions
9    * are met:
10   *
11   * 1. Redistributions of source code must retain the above copyright
12   *    notice, this list of conditions and the following disclaimer.
13   *
14   * 2. Redistributions in binary form must reproduce the above copyright
15   *    notice, this list of conditions and the following disclaimer in
16   *    the documentation and/or other materials provided with the
17   *    distribution.
18   *
19   * 3. The end-user documentation included with the redistribution,
20   *    if any, must include the following acknowledgment:
21   *       "This product includes software developed by
22   *        Yasna.com (http://www.yasna.com)."
23   *    Alternately, this acknowledgment may appear in the software itself,
24   *    if and wherever such third-party acknowledgments normally appear.
25   *
26   * 4. The names "Yazd" and "Yasna.com" must not be used to
27   *    endorse or promote products derived from this software without
28   *    prior written permission. For written permission, please
29   *    contact yazd@yasna.com.
30   *
31   * 5. Products derived from this software may not be called "Yazd",
32   *    nor may "Yazd" appear in their name, without prior written
33   *    permission of Yasna.com.
34   *
35   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
36   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
37   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
38   * DISCLAIMED.  IN NO EVENT SHALL YASNA.COM OR
39   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
42   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
43   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
44   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
45   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46   * SUCH DAMAGE.
47   * ====================================================================
48   *
49   * This software consists of voluntary contributions made by many
50   * individuals on behalf of Yasna.com. For more information
51   * on Yasna.com, please see <http://www.yasna.com>.
52   */
53  
54  /**
55   * Copyright (C) 2000 CoolServlets.com. All rights reserved.
56   *
57   * ===================================================================
58   * The Apache Software License, Version 1.1
59   *
60   * Redistribution and use in source and binary forms, with or without
61   * modification, are permitted provided that the following conditions
62   * are met:
63   *
64   * 1. Redistributions of source code must retain the above copyright
65   *    notice, this list of conditions and the following disclaimer.
66   *
67   * 2. Redistributions in binary form must reproduce the above copyright
68   *    notice, this list of conditions and the following disclaimer in
69   *    the documentation and/or other materials provided with the
70   *    distribution.
71   *
72   * 3. The end-user documentation included with the redistribution,
73   *    if any, must include the following acknowledgment:
74   *       "This product includes software developed by
75   *        CoolServlets.com (http://www.coolservlets.com)."
76   *    Alternately, this acknowledgment may appear in the software itself,
77   *    if and wherever such third-party acknowledgments normally appear.
78   *
79   * 4. The names "Jive" and "CoolServlets.com" must not be used to
80   *    endorse or promote products derived from this software without
81   *    prior written permission. For written permission, please
82   *    contact webmaster@coolservlets.com.
83   *
84   * 5. Products derived from this software may not be called "Jive",
85   *    nor may "Jive" appear in their name, without prior written
86   *    permission of CoolServlets.com.
87   *
88   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
89   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
90   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
91   * DISCLAIMED.  IN NO EVENT SHALL COOLSERVLETS.COM OR
92   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
93   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
94   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
95   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
96   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
97   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
98   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99   * SUCH DAMAGE.
100  * ====================================================================
101  *
102  * This software consists of voluntary contributions made by many
103  * individuals on behalf of CoolServlets.com. For more information
104  * on CoolServlets.com, please see <http://www.coolservlets.com>.
105  */
106 
107 package com.Yasna.forum.tags;
108 
109 import java.io.*;
110 import javax.servlet.*;
111 import javax.servlet.jsp.*;
112 import javax.servlet.jsp.tagext.*;
113 import javax.servlet.http.*;
114 import com.Yasna.forum.tags.*;
115 
116 /**
117  * JSP Tag <b>true</b>, used to test the result of an <b>eval</b> tag
118  * for true.
119  * <p>
120  * Requires that attribute <b>eval</b> be set to the name of a
121  * script variable <b>id</b> of a previous <b>eval</b> tag.
122  * <p>
123  * Includes body of tag if result of <b>eval</b> tag was true.
124  * <p>
125  * JSP Tag Lib Descriptor
126  * <p><pre>
127  *  &lt;name&gt;true&lt;/name&gt;
128  *  &lt;tagclass&gt;com.Yasna.forum.tags.TrueTag&lt;/tagclass&gt;
129  *  &lt;bodycontent&gt;JSP&lt;/bodycontent&gt;
130  *  &lt;info&gt;Evaluate an expression&lt;/info&gt;
131  *  &lt;attribute&gt;
132  *    &lt;name&gt;eval&lt;/name&gt;
133  *    &lt;required&gt;true&lt;/required&gt;
134  *    &lt;rtexprvalue&gt;false&lt;/rtexprvalue&gt;
135  *  &lt;/attribute&gt;
136  * </pre>
137  *
138  * @see EvalTag
139  *
140  * @author Glenn Nielsen
141  */
142 public class TrueTag extends TagSupport
143 {
144   // id of eval script variable which contains the boolean result
145   private String   eval = null;
146 
147   /**
148    * Gets the result of a previous eval
149    *
150    * @return EVAL_BODY_INCLUDE if result of eval was true, or SKIP_BODY if the result was false
151    */
152   public final int doStartTag() throws JspException
153   {
154     Boolean   res;
155 
156     res = (Boolean  )pageContext.getAttribute(eval,PageContext.PAGE_SCOPE);
157     if( res == null )
158       throw new JspException("Jive true tag could not find eval \"" +
159     eval + "\"");
160     if( res.booleanValue() )
161       return EVAL_BODY_INCLUDE;
162     return SKIP_BODY;
163   }
164 
165   /**
166    * Set the name of the eval tag script variable id
167    */
168   public final void setEval(String   nam)
169   {
170     eval = nam;
171   }
172 
173 }
174
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