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 */
019package org.apache.wiki.tags;
020
021import java.io.IOException;
022
023import org.apache.wiki.WikiPage;
024
025/**
026 *  Outputs the version number of the previous version of this page.
027 *
028 *  @since 2.2
029 */
030public class PreviousVersionTag
031    extends WikiTagBase
032{
033    private static final long serialVersionUID = 0L;
034    
035    /**
036     *  {@inheritDoc}
037     */
038    @Override
039    public final int doWikiStartTag()
040        throws IOException
041    {
042        WikiPage   page   = m_wikiContext.getPage();
043
044        int version = page.getVersion();
045
046        version--;
047
048        if( version > 0 )
049            pageContext.getOut().print( version );
050
051        return SKIP_BODY;
052    }
053}