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Java > Open Source Codes > com > Yasna > forum > tags > PrevThreadTag


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 java.util.*;
111 import javax.servlet.*;
112 import javax.servlet.jsp.*;
113 import javax.servlet.jsp.tagext.*;
114 import javax.servlet.http.*;
115 import com.Yasna.forum.*;
116 import com.Yasna.forum.tags.*;
117
118 /**
119  * JSP Tag <b>prev_thread</b>, used to test if there is a thread
120  * preceding the current thread in the current forum.
121  * <p>
122  * Includes body of tag if there is a previous thread.
123  * <p>
124  * Must be nested inside a <b>thread</b> tag.
125  * <p>
126  * JSP Tag Lib Descriptor
127  * <p><pre>
128  * &lt;name&gt;prev_thread&lt;/name&gt;
129  * &lt;tagclass&gt;com.Yasna.thread.tags.PrevThreadTag&lt;/tagclass&gt;
130  * &lt;bodycontent&gt;JSP&lt;/bodycontent&gt;
131  * &lt;info&gt;
132  * Includes body of tag if there is a thread preceding the current
133  * thread in the current forum.
134  * &lt;/info&gt;
135  * &lt;attribute&gt;
136  * &lt;name&gt;value&lt;/name&gt;
137  * &lt;required&gt;false&lt;/required&gt;
138  * &lt;rtexprvalue&gt;false&lt;/rtexprvalue&gt;
139  * &lt;/attribute&gt;
140  * </pre>
141  *
142  * @see ThreadTag
143  *
144  * @author Glenn Nielsen
145  */

146
147 public class PrevThreadTag extends TagSupport
148 {
149   private Boolean JavaDoc value = null;
150
151   /**
152    * Method called at start of prev_thread Tag
153    *
154    * @return EVAL_BODY if there is a previous thread or SKIP_BODY if thia is the first thread
155    */

156   public final int doStartTag() throws JspException
157   {
158     boolean result = false;
159
160     // Find the parent tag of type ThreadTag
161
ThreadTag tt = null;
162     try {
163       tt = (ThreadTag)this.findAncestorWithClass(this,
164         Class.forName("com.Yasna.forum.tags.ThreadTag"));
165       result = tt.prevThread();
166     } catch(Exception JavaDoc e) {
167     }
168
169     if( value == null ) {
170       if( result )
171         return EVAL_BODY_INCLUDE;
172     } else {
173       if( value.booleanValue() == result )
174         return EVAL_BODY_INCLUDE;
175     }
176
177     return SKIP_BODY;
178   }
179
180   /**
181    * Set the value of the optional attribute value to "true" or "false".
182    *
183    * @param String "true" or "false"
184    */

185   public void setValue(String JavaDoc str)
186   {
187      value = new Boolean JavaDoc(str);
188   }
189 }
190
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