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;
022import java.util.Collection;
023
024import javax.servlet.jsp.JspWriter;
025import javax.servlet.jsp.PageContext;
026
027import org.apache.log4j.Logger;
028import org.apache.wiki.WikiEngine;
029import org.apache.wiki.WikiContext;
030import org.apache.wiki.WikiPage;
031import org.apache.wiki.api.exceptions.ProviderException;
032
033/**
034 *  Iterates through tags.
035 *
036 *  <P><B>Attributes</B></P>
037 *  <UL>
038 *    <LI>page - Page name to refer to.  Default is the current page.
039 *  </UL>
040 *
041 *  @since 2.0
042 */
043
044// FIXME: Too much in common with IteratorTag - REFACTOR
045public class HistoryIteratorTag
046    extends IteratorTag
047{
048    private static final long serialVersionUID = 0L;
049    
050    static    Logger    log = Logger.getLogger( HistoryIteratorTag.class );
051
052    public final int doStartTag()
053    {
054        m_wikiContext = (WikiContext) pageContext.getAttribute( WikiTagBase.ATTR_CONTEXT,
055                                                                PageContext.REQUEST_SCOPE );
056
057        WikiEngine engine = m_wikiContext.getEngine();
058        WikiPage   page;
059
060        page = m_wikiContext.getPage();
061
062        try
063        {
064            if( page != null && engine.pageExists(page) )
065            {
066                Collection versions = engine.getVersionHistory( page.getName() );
067
068                if( versions == null )
069                {
070                    // There is no history
071                    return SKIP_BODY;
072                }
073
074                m_iterator = versions.iterator();
075
076                if( m_iterator.hasNext() )
077                {
078                    WikiContext context = (WikiContext)m_wikiContext.clone();
079                    context.setPage( (WikiPage)m_iterator.next() );
080                    pageContext.setAttribute( WikiTagBase.ATTR_CONTEXT,
081                                              context,
082                                              PageContext.REQUEST_SCOPE );
083                    pageContext.setAttribute( getId(),
084                                              context.getPage() );
085                }
086                else
087                {
088                    return SKIP_BODY;
089                }
090            }
091
092            return EVAL_BODY_BUFFERED;
093        }
094        catch( ProviderException e )
095        {
096            log.fatal("Provider failed while trying to iterator through history",e);
097            // FIXME: THrow something.
098        }
099
100        return SKIP_BODY;
101    }
102
103    public final int doAfterBody()
104    {
105        if( bodyContent != null )
106        {
107            try
108            {
109                JspWriter out = getPreviousOut();
110                out.print(bodyContent.getString());
111                bodyContent.clearBody();
112            }
113            catch( IOException e )
114            {
115                log.error("Unable to get inner tag text", e);
116                // FIXME: throw something?
117            }
118        }
119
120        if( m_iterator != null && m_iterator.hasNext() )
121        {
122            WikiContext context = (WikiContext)m_wikiContext.clone();
123            context.setPage( (WikiPage)m_iterator.next() );
124            pageContext.setAttribute( WikiTagBase.ATTR_CONTEXT,
125                                      context,
126                                      PageContext.REQUEST_SCOPE );
127            pageContext.setAttribute( getId(),
128                                      context.getPage() );
129            return EVAL_BODY_BUFFERED;
130        }
131
132        return SKIP_BODY;
133    }
134}