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 org.apache.wiki.InternalWikiException;
024 import org.apache.wiki.WikiEngine;
025 import org.apache.wiki.WikiPage;
026 import org.apache.wiki.api.exceptions.ProviderException;
027
028 /**
029 * Does a version check on the page. Mode is as follows:
030 * <UL>
031 * <LI><b>latest</b> - Include body, if the page is the latest version.</li>
032 * <LI><b>notlatest</b> - Include body, if the page is NOT the latest version.</li>
033 * <li><b>first</b> - Include body, if page is the first version (version 1)</li>
034 * <li><b>notfirst</b> - Include bodt, if page is NOT the first version (version 1)</li>
035 * </UL>
036 * If the page does not exist, body content is never included.
037 *
038 * @since 2.0
039 */
040 public class CheckVersionTag
041 extends WikiTagBase
042 {
043 private static final long serialVersionUID = 0L;
044
045 private static enum VersionMode
046 {
047 LATEST, NOTLATEST, FIRST, NOTFIRST
048 }
049
050 private VersionMode m_mode;
051
052 /**
053 * {@inheritDoc}
054 */
055 @Override
056 public void initTag()
057 {
058 super.initTag();
059 m_mode = VersionMode.LATEST;
060 }
061
062 /**
063 * Sets the mode.
064 *
065 * @param arg The mode to set.
066 */
067 public void setMode( String arg )
068 {
069 if( "latest".equals(arg) )
070 {
071 m_mode = VersionMode.LATEST;
072 }
073 else if( "notfirst".equals(arg) )
074 {
075 m_mode = VersionMode.NOTFIRST;
076 }
077 else if( "first".equals(arg) )
078 {
079 m_mode = VersionMode.FIRST;
080 }
081 else
082 {
083 m_mode = VersionMode.NOTLATEST;
084 }
085 }
086
087 /**
088 * {@inheritDoc}
089 */
090 @Override
091 public final int doWikiStartTag()
092 throws IOException,
093 ProviderException
094 {
095 WikiEngine engine = m_wikiContext.getEngine();
096 WikiPage page = m_wikiContext.getPage();
097
098 if( page != null && engine.pageExists(page.getName()) )
099 {
100 int version = page.getVersion();
101 boolean include = false;
102
103 WikiPage latest = engine.getPage( page.getName() );
104
105 //log.debug("Doing version check: this="+page.getVersion()+
106 // ", latest="+latest.getVersion());
107
108 switch( m_mode )
109 {
110 case LATEST:
111 include = (version < 0) || (latest.getVersion() == version);
112 break;
113
114 case NOTLATEST:
115 include = (version > 0) && (latest.getVersion() != version);
116 break;
117
118 case FIRST:
119 include = (version == 1 ) || (version < 0 && latest.getVersion() == 1);
120 break;
121
122 case NOTFIRST:
123 include = version > 1;
124 break;
125
126 default:
127 throw new InternalWikiException("Mode which is not available!");
128 }
129
130 if( include )
131 {
132 // log.debug("INCLD");
133 return EVAL_BODY_INCLUDE;
134 }
135 }
136
137 return SKIP_BODY;
138 }
139 }