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


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>is_parent</b>, used to test if the current message
118  * is a parent message that was already fully displayed on the
119  * previous page during a thread <b>walk</b>.
120  * <p>
121  * Includes body of tag if this is a parent of the first new message
122  * to display on this page.
123  * <p>
124  * Must be nested inside a <b>walk</b> tag.
125  * <p>
126  * JSP Tag Lib Descriptor
127  * <p><pre>
128  * &lt;name&gt;is_parent&lt;/name&gt;
129  * &lt;tagclass&gt;com.Yasna.forum.tags.IsParentTag&lt;/tagclass&gt;
130  * &lt;bodycontent&gt;JSP&lt;/bodycontent&gt;
131  * &lt;info&gt;
132  * When walking a tree of messages, body is included if this is a
133  * parent message to the starting message for this page.
134  * &lt;/info&gt;
135  * </pre>
136  *
137  * @see WalkTag
138  *
139  * @author Glenn Nielsen
140  */
141 public class IsParentTag extends TagSupport
142 {
143
144   /**
145    * Method called at start of is_parent Tag
146    *
147    * @return EVAL_BODY if this is a parent of the first new message on this page or SKIP_BODY if this is a message that wasn't displayed on previous page
148    */
149   public final int doStartTag() throws JspException
150   {
151     // Find the parent walk tag
152 WalkTag wt = null;
153     try {
154       wt = (WalkTag)this.findAncestorWithClass(this,
155         Class.forName("com.Yasna.forum.tags.WalkTag"));
156     } catch(Exception JavaDoc e) {
157       return SKIP_BODY;
158     }
159
160     if( wt != null && wt.isParentMessage() )
161       return EVAL_BODY_INCLUDE;
162     return SKIP_BODY;
163   }
164
165 }
166
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