001 /*
002 Licensed to the Apache Software Foundation (ASF) under one
003 or more contributor license agreements. See the NOTICE file
004 distributed with this work for additional information
005 regarding copyright ownership. The ASF licenses this file
006 to you under the Apache License, Version 2.0 (the
007 "License"); you may not use this file except in compliance
008 with the License. You may obtain a copy of the License at
009
010 http://www.apache.org/licenses/LICENSE-2.0
011
012 Unless required by applicable law or agreed to in writing,
013 software distributed under the License is distributed on an
014 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 KIND, either express or implied. See the License for the
016 specific language governing permissions and limitations
017 under the License.
018 */
019 package org.apache.wiki.tags;
020
021 import java.io.IOException;
022
023 import javax.servlet.jsp.JspWriter;
024 import javax.servlet.jsp.PageContext;
025
026 import org.apache.log4j.Logger;
027 import org.apache.wiki.WikiContext;
028 import org.apache.wiki.WikiEngine;
029
030 /**
031 * Writes difference between two pages using a HTML table. If there is
032 * no difference, includes the body.
033 *
034 * <P><B>Attributes</B></P>
035 * <UL>
036 * <LI>page - Page name to refer to. Default is the current page.
037 * </UL>
038 *
039 * @since 2.0
040 */
041 public class InsertDiffTag extends WikiTagBase {
042
043 private static final long serialVersionUID = 0L;
044 private static final Logger log = Logger.getLogger( InsertDiffTag.class );
045
046 /** Attribute which is used to store the old page content to the Page Context */
047 public static final String ATTR_OLDVERSION = "olddiff";
048
049 /** Attribute which is used to store the new page content to the Page Context */
050 public static final String ATTR_NEWVERSION = "newdiff";
051
052 protected String m_pageName;
053
054 /** {@inheritDoc} */
055 public void initTag()
056 {
057 super.initTag();
058 m_pageName = null;
059 }
060
061 /**
062 * Sets the page name.
063 * @param page Page to get diff from.
064 */
065 public void setPage( String page )
066 {
067 m_pageName = page;
068 }
069
070 /**
071 * Gets the page name.
072 * @return The page name.
073 */
074 public String getPage()
075 {
076 return m_pageName;
077 }
078
079 /** {@inheritDoc} */
080 public final int doWikiStartTag()
081 throws IOException
082 {
083 WikiEngine engine = m_wikiContext.getEngine();
084 WikiContext ctx;
085
086 if( m_pageName == null )
087 {
088 ctx = m_wikiContext;
089 }
090 else
091 {
092 ctx = (WikiContext)m_wikiContext.clone();
093 ctx.setPage( engine.getPage(m_pageName) );
094 }
095
096 Integer vernew = (Integer) pageContext.getAttribute( ATTR_NEWVERSION,
097 PageContext.REQUEST_SCOPE );
098 Integer verold = (Integer) pageContext.getAttribute( ATTR_OLDVERSION,
099 PageContext.REQUEST_SCOPE );
100
101 log.info("Request diff between version "+verold+" and "+vernew);
102
103 if( ctx.getPage() != null )
104 {
105 JspWriter out = pageContext.getOut();
106
107 String diff = engine.getDiff( ctx,
108 vernew.intValue(),
109 verold.intValue() );
110
111 if( diff.length() == 0 )
112 {
113 return EVAL_BODY_INCLUDE;
114 }
115
116 out.write( diff );
117 }
118
119 return SKIP_BODY;
120 }
121 }
122