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.plugin;
020
021import org.apache.log4j.Logger;
022import org.apache.wiki.api.core.Context;
023import org.apache.wiki.api.core.ContextEnum;
024import org.apache.wiki.api.core.Page;
025import org.apache.wiki.api.exceptions.PluginException;
026import org.apache.wiki.api.plugin.Plugin;
027import org.apache.wiki.pages.PageManager;
028import org.apache.wiki.preferences.Preferences;
029import org.apache.wiki.references.ReferenceManager;
030import org.apache.wiki.util.TextUtil;
031
032import java.text.MessageFormat;
033import java.util.Collection;
034import java.util.Map;
035import java.util.ResourceBundle;
036
037/**
038 *  Displays the pages referring to the current page.
039 *
040 *  Parameters:
041 *  <ul>
042 *  <li><b>max</b> - How many items to show.</li>
043 *  <li><b>extras</b> - How to announce extras.</li>
044 *  <li><b>page</b> - Which page to get the table of contents from.</li>
045 *  </ul>
046 *
047 *  From AbstractReferralPlugin:
048 *  <ul>
049 *  <li><b>separator</b> - How to separate generated links; default is a wikitext line break, producing a vertical list.</li>
050 *  <li><b>maxwidth</b> - maximum width, in chars, of generated links.</li>
051 *  </ul>
052 */
053public class ReferringPagesPlugin extends AbstractReferralPlugin {
054
055    private static final Logger log = Logger.getLogger( ReferringPagesPlugin.class );
056
057    /** Parameter name for setting the maximum items to show.  Value is <tt>{@value}</tt>. */
058    public static final String PARAM_MAX      = "max";
059
060    /** Parameter name for setting the text to show when the maximum items is overruled. Value is <tt>{@value}</tt>. */
061    public static final String PARAM_EXTRAS   = "extras";
062
063    /** Parameter name for choosing the page.  Value is <tt>{@value}</tt>. */
064    public static final String PARAM_PAGE     = "page";
065
066    /**
067     *  {@inheritDoc}
068     */
069    @Override
070    public String execute( final Context context, final Map< String, String > params ) throws PluginException {
071        final ReferenceManager refmgr = context.getEngine().getManager( ReferenceManager.class );
072        String pageName = params.get( PARAM_PAGE );
073        final ResourceBundle rb = Preferences.getBundle( context, Plugin.CORE_PLUGINS_RESOURCEBUNDLE );
074
075        StringBuilder result = new StringBuilder( 256 );
076
077        if( pageName == null ) {
078            pageName = context.getPage().getName();
079        }
080
081        final Page page = context.getEngine().getManager( PageManager.class ).getPage( pageName );
082
083        if( page != null ) {
084            Collection< String > links  = refmgr.findReferrers( page.getName() );
085            String wikitext;
086
087            super.initialize( context, params );
088
089            final int items = TextUtil.parseIntParameter( params.get( PARAM_MAX ), ALL_ITEMS );
090
091            String extras = TextUtil.replaceEntities( params.get( PARAM_EXTRAS ) );
092            if( extras == null ) {
093                extras = rb.getString("referringpagesplugin.more");
094            }
095
096            if( log.isDebugEnabled() ) {
097                log.debug( "Fetching referring pages for " + page.getName() + " with a max of "+items);
098            }
099
100            if( links != null && links.size() > 0 ) {
101                links = filterAndSortCollection( links );
102                wikitext = wikitizeCollection( links, m_separator, items );
103
104                result.append( makeHTML( context, wikitext ) );
105
106                if( items < links.size() && items > 0 )
107                {
108                    final Object[] args = { "" + ( links.size() - items) };
109                    extras = MessageFormat.format(extras, args);
110
111                    result.append( "<br />" )
112                          .append( "<a class='morelink' href='" )
113                          .append( context.getURL( ContextEnum.PAGE_INFO.getRequestContext(), page.getName() ) )
114                          .append( "' " )
115                          .append( ">" )
116                          .append( extras )
117                          .append( "</a><br />" );
118                }
119            }
120
121            //
122            // If nothing was left after filtering or during search
123            //
124            if( links == null || links.size() == 0 ) {
125                wikitext = rb.getString( "referringpagesplugin.nobody" );
126
127                result.append( makeHTML( context, wikitext ) );
128            } else {
129                if( m_show.equals( PARAM_SHOW_VALUE_COUNT ) ) {
130                    result = new StringBuilder();
131                    result.append( links.size() );
132                    if( m_lastModified ) {
133                        result.append( " (" ).append( m_dateFormat.format( m_dateLastModified ) ).append( ")" );
134                    }
135                }
136            }
137
138            return result.toString();
139        }
140
141        return "";
142    }
143
144}