    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}