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 org.apache.log4j.Logger;
022import org.apache.wiki.api.core.Context;
023import org.apache.wiki.api.core.Engine;
024import org.apache.wiki.api.core.Page;
025import org.apache.wiki.api.exceptions.ProviderException;
026import org.apache.wiki.pages.PageManager;
027
028import javax.servlet.jsp.JspWriter;
029import javax.servlet.jsp.PageContext;
030import java.io.IOException;
031import java.util.List;
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// FIXME: Too much in common with IteratorTag - REFACTOR
044public class HistoryIteratorTag extends IteratorTag  {
045
046    private static final long serialVersionUID = 0L;
047    private static final Logger LOG = Logger.getLogger( HistoryIteratorTag.class );
048
049    /** {@inheritDoc} */
050    @Override
051    public final int doStartTag() {
052        m_wikiContext = (Context) pageContext.getAttribute( Context.ATTR_CONTEXT, PageContext.REQUEST_SCOPE );
053        final Engine engine = m_wikiContext.getEngine();
054        final Page page = m_wikiContext.getPage();
055
056        try {
057            if( page != null && engine.getManager( PageManager.class ).wikiPageExists( page ) ) {
058                final List< Page > versions = engine.getManager( PageManager.class ).getVersionHistory( page.getName() );
059
060                if( versions == null ) {
061                    // There is no history
062                    return SKIP_BODY;
063                }
064
065                m_iterator = versions.iterator();
066
067                if( m_iterator.hasNext() ) {
068                    final Context context = m_wikiContext.clone();
069                    context.setPage( ( Page )m_iterator.next() );
070                    pageContext.setAttribute( Context.ATTR_CONTEXT, context, PageContext.REQUEST_SCOPE );
071                    pageContext.setAttribute( getId(), context.getPage() );
072                } else {
073                    return SKIP_BODY;
074                }
075            }
076
077            return EVAL_BODY_BUFFERED;
078        } catch( final ProviderException e ) {
079            LOG.fatal("Provider failed while trying to iterator through history",e);
080            // FIXME: THrow something.
081        }
082
083        return SKIP_BODY;
084    }
085
086    /** {@inheritDoc} */
087    @Override
088    public final int doAfterBody() {
089        if( bodyContent != null ) {
090            try {
091                final JspWriter out = getPreviousOut();
092                out.print(bodyContent.getString());
093                bodyContent.clearBody();
094            } catch( final IOException e ) {
095                LOG.error("Unable to get inner tag text", e);
096                // FIXME: throw something?
097            }
098        }
099
100        if( m_iterator != null && m_iterator.hasNext() ) {
101            final Context context = m_wikiContext.clone();
102            context.setPage( ( Page )m_iterator.next() );
103            pageContext.setAttribute( Context.ATTR_CONTEXT, context, PageContext.REQUEST_SCOPE );
104            pageContext.setAttribute( getId(), context.getPage() );
105            return EVAL_BODY_BUFFERED;
106        }
107
108        return SKIP_BODY;
109    }
110
111}