001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software GmbH & Co. KG, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.staticexport;
029
030import org.opencms.relations.CmsLink;
031import org.opencms.relations.CmsRelationType;
032
033import java.util.Comparator;
034import java.util.Iterator;
035import java.util.Map;
036import java.util.TreeMap;
037import java.util.regex.Matcher;
038import java.util.regex.Pattern;
039
040import org.apache.commons.lang3.BooleanUtils;
041
042import com.google.common.collect.ComparisonChain;
043
044/**
045 * Maintains a table of links for an element of a CmsXmlPage.<p>
046 *
047 * @since 6.0.0
048 */
049public class CmsLinkTable {
050
051    /**
052     * Comparator used to deterministically order the link table.<p>
053     */
054    public static class LinkKeyComparator implements Comparator<String> {
055
056        /**
057         * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
058         */
059        public int compare(String a, String b) {
060
061            if ((a == null) || (b == null)) {
062                // null is "less" than any other string
063                return BooleanUtils.toInteger(b == null) - BooleanUtils.toInteger(a == null);
064            }
065            Matcher matcherA = LINK_PATTERN.matcher(a);
066            Matcher matcherB = LINK_PATTERN.matcher(b);
067            matcherA.find();
068            matcherB.find();
069            String nameA = matcherA.group(1);
070            // prepend "0" so we don't get an exception for the empty string
071            int indexA = Integer.parseInt("0" + matcherA.group(2));
072            String nameB = matcherB.group(1);
073            int indexB = Integer.parseInt("0" + matcherB.group(2));
074            int result = ComparisonChain.start().compare(nameA, nameB).compare(indexA, indexB).compare(a, b).result();
075            return result;
076
077        }
078    }
079
080    /** Prefix to identify a link in the content. */
081    private static final String LINK_PREFIX = "link";
082
083    /** Pattern used to extract the index and the part before the index from a link id. */
084    public static final Pattern LINK_PATTERN = Pattern.compile("^(.*?)([0-9]*)$");
085
086    /** The map to store the link table in. */
087    private Map<String, CmsLink> m_linkTable;
088
089    /**
090     * Creates a new CmsLinkTable.<p>
091     */
092    public CmsLinkTable() {
093
094        m_linkTable = new TreeMap<String, CmsLink>(new LinkKeyComparator());
095    }
096
097    /**
098     * Adds a new link with a given internal name and internal flag to the link table.<p>
099     *
100     * @param link the <code>CmsLink</code> to add
101     * @return the new link entry
102     */
103    public CmsLink addLink(CmsLink link) {
104
105        m_linkTable.put(link.getName(), link);
106        return link;
107    }
108
109    /**
110     * Adds a new link to the link table.<p>
111     *
112     * @param type type of the link
113     * @param targetUri link destination
114     * @param internal flag to indicate if the link is a local link
115     *
116     * @return the new link entry
117     */
118    public CmsLink addLink(CmsRelationType type, String targetUri, boolean internal) {
119
120        CmsLink link = new CmsLink(LINK_PREFIX + m_linkTable.size(), type, targetUri, internal);
121        m_linkTable.put(link.getName(), link);
122        return link;
123    }
124
125    /**
126     * Returns the CmsLink Entry for a given name.<p>
127     *
128     * @param name the internal name of the link
129     * @return the CmsLink entry
130     */
131    public CmsLink getLink(String name) {
132
133        return m_linkTable.get(name);
134    }
135
136    /**
137     * Returns if the link table is empty.<p>
138     *
139     * @return true if the link table is empty, false otherwise
140     */
141    public boolean isEmpty() {
142
143        return m_linkTable.isEmpty();
144    }
145
146    /**
147     * Returns an iterator over the links in the table.<p>
148     *
149     * The objects iterated are of type <code>{@link CmsLink}</code>.
150     *
151     * @return a string iterator for internal link names
152     */
153    public Iterator<CmsLink> iterator() {
154
155        return m_linkTable.values().iterator();
156    }
157
158    /**
159     * Returns the size of this link table.<p>
160     *
161     * @return the size of this link table
162     */
163    public int size() {
164
165        return m_linkTable.size();
166    }
167}