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.List;
023
024import javax.servlet.jsp.JspWriter;
025import javax.servlet.jsp.PageContext;
026
027import org.apache.log4j.Logger;
028import org.apache.wiki.WikiContext;
029import org.apache.wiki.WikiEngine;
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    @Override
053    public final int doStartTag() {
054        m_wikiContext = (WikiContext) pageContext.getAttribute( WikiTagBase.ATTR_CONTEXT, PageContext.REQUEST_SCOPE );
055
056        WikiEngine engine = m_wikiContext.getEngine();
057        WikiPage   page;
058
059        page = m_wikiContext.getPage();
060
061        try
062        {
063            if( page != null && engine.pageExists(page) )
064            {
065                @SuppressWarnings("unchecked")
066                List< WikiPage > versions = ( List< WikiPage > )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, context, PageContext.REQUEST_SCOPE );
081                    pageContext.setAttribute( getId(), context.getPage() );
082                }
083                else
084                {
085                    return SKIP_BODY;
086                }
087            }
088
089            return EVAL_BODY_BUFFERED;
090        }
091        catch( ProviderException e )
092        {
093            log.fatal("Provider failed while trying to iterator through history",e);
094            // FIXME: THrow something.
095        }
096
097        return SKIP_BODY;
098    }
099
100    @Override
101    public final int doAfterBody()
102    {
103        if( bodyContent != null )
104        {
105            try
106            {
107                JspWriter out = getPreviousOut();
108                out.print(bodyContent.getString());
109                bodyContent.clearBody();
110            }
111            catch( IOException e )
112            {
113                log.error("Unable to get inner tag text", e);
114                // FIXME: throw something?
115            }
116        }
117
118        if( m_iterator != null && m_iterator.hasNext() )
119        {
120            WikiContext context = (WikiContext)m_wikiContext.clone();
121            context.setPage( (WikiPage)m_iterator.next() );
122            pageContext.setAttribute( WikiTagBase.ATTR_CONTEXT, context, PageContext.REQUEST_SCOPE );
123            pageContext.setAttribute( getId(), context.getPage() );
124            return EVAL_BODY_BUFFERED;
125        }
126
127        return SKIP_BODY;
128    }
129}