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.wiki.api.core.Engine;
022import org.apache.wiki.api.core.Page;
023import org.apache.wiki.api.exceptions.ProviderException;
024import org.apache.wiki.pages.PageLock;
025import org.apache.wiki.pages.PageManager;
026
027import javax.servlet.http.HttpSession;
028import java.io.IOException;
029
030/**
031 *  Checks whether the page is locked for editing.  If the mode matches,
032 *  the tag body is included.  The "mode" can be any of the following:
033 *  
034 *  <ul>
035 *  <li><b>locked</b> - The page is currently locked, but the lock is owned by someone else.</li>
036 *  <li><b>owned</b> - The page is currently locked and the current user is the owner of the lock.</li>
037 *  <li><b>unlocked</b> - Nobody has locked the page.</li>
038 *  </ul>
039 *  
040 *  @since 2.0
041 */
042public class CheckLockTag extends WikiTagBase {
043
044    private static final long serialVersionUID = 1L;
045    
046    private enum LockState {
047        LOCKED, NOTLOCKED, OWNED
048    }
049
050    private LockState m_mode;
051
052    /**
053     *  {@inheritDoc}
054     */
055    @Override
056    public void initTag() {
057        super.initTag();
058        m_mode = LockState.NOTLOCKED;
059    }
060
061    /**
062     *  Sets the mode to check for.
063     *  
064     *  @param arg A String for the mode.
065     */
066    public void setMode( final String arg ) {
067        if( "locked".equals( arg ) ) {
068            m_mode = LockState.LOCKED;
069        } else if( "owned".equals( arg ) ) {
070            m_mode = LockState.OWNED;
071        } else {
072            m_mode = LockState.NOTLOCKED;
073        }
074    }
075
076    /**
077     *  {@inheritDoc}
078     */
079    @Override
080    public final int doWikiStartTag() throws IOException, ProviderException {
081        final Engine engine = m_wikiContext.getEngine();
082        final Page page = m_wikiContext.getPage();
083
084        if( page != null ) {
085            final PageManager mgr = engine.getManager( PageManager.class );
086            final PageLock lock = mgr.getCurrentLock( page );
087            final HttpSession session = pageContext.getSession();
088            final PageLock userLock = ( PageLock )session.getAttribute( "lock-" + page.getName() );
089            if( ( lock != null && m_mode == LockState.LOCKED && lock != userLock ) ||
090                ( lock != null && m_mode == LockState.OWNED && lock == userLock )  ||
091                ( lock == null && m_mode == LockState.NOTLOCKED ) ) {
092
093                final String tid = getId();
094                if( tid != null && lock != null ) {
095                    pageContext.setAttribute( tid, lock );
096                }
097
098                return EVAL_BODY_INCLUDE;
099            }
100        }
101
102        return SKIP_BODY;
103    }
104
105}