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 java.text.MessageFormat;
022import java.util.Collection;
023import java.util.Map;
024import java.util.ResourceBundle;
025
026import org.apache.log4j.Logger;
027import org.apache.wiki.ReferenceManager;
028import org.apache.wiki.WikiContext;
029import org.apache.wiki.WikiPage;
030import org.apache.wiki.api.exceptions.PluginException;
031import org.apache.wiki.api.plugin.WikiPlugin;
032import org.apache.wiki.preferences.Preferences;
033import org.apache.wiki.util.TextUtil;
034
035/**
036 *  Displays the pages referring to the current page.
037 *
038 *  Parameters:
039 *  <ul>
040 *  <li><b>max</b> - How many items to show.</li>
041 *  <li><b>extras</b> - How to announce extras.</li>
042 *  <li><b>page</b> - Which page to get the table of contents from.</li>
043 *  </ul>
044 *  
045 *  From AbstractReferralPlugin:
046 *  <ul>
047 *  <li><b>separator</b> - How to separate generated links; default is a wikitext line break,
048 *             producing a vertical list.</li>
049 *  <li><b>maxwidth</b> - maximum width, in chars, of generated links.</li>
050 *  </ul>
051 */
052public class ReferringPagesPlugin
053    extends AbstractReferralPlugin
054{
055    private static 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.  
061     *  Value is <tt>{@value}</tt>. 
062     */
063    public static final String PARAM_EXTRAS   = "extras";
064    
065    /**
066     *  Parameter name for choosing the page.  Value is <tt>{@value}</tt>.
067     */
068    public static final String PARAM_PAGE     = "page";
069    
070    /**
071     *  {@inheritDoc}
072     */
073    public String execute( WikiContext context, Map<String, String> params )
074        throws PluginException
075    {
076        ReferenceManager refmgr = context.getEngine().getReferenceManager();
077        String pageName = params.get( PARAM_PAGE );
078        ResourceBundle rb = Preferences.getBundle( context, WikiPlugin.CORE_PLUGINS_RESOURCEBUNDLE );
079        
080        StringBuilder result = new StringBuilder( 256 );
081        
082        if( pageName == null )
083        {
084            pageName = context.getPage().getName();
085        }
086
087        WikiPage page = context.getEngine().getPage( pageName );
088        
089        if( page != null )
090        {
091            Collection   links  = refmgr.findReferrers( page.getName() );
092            String       wikitext = "";
093
094            super.initialize( context, params );
095
096            int items = TextUtil.parseIntParameter( params.get( PARAM_MAX ), ALL_ITEMS );
097            String extras = params.get( PARAM_EXTRAS );
098            if( extras == null )
099            {
100                extras = rb.getString("referringpagesplugin.more");
101            }
102            
103            if( log.isDebugEnabled() )
104                log.debug( "Fetching referring pages for "+page.getName()+
105                           " with a max of "+items);
106        
107            if( links != null && links.size() > 0 )
108            {
109                links = filterAndSortCollection( links );
110                wikitext = wikitizeCollection( links, m_separator, items );
111
112                result.append( makeHTML( context, wikitext ) );
113                
114                if( items < links.size() && items > 0 )
115                {
116                    Object[] args = { "" + ( links.size() - items) };
117                    extras = MessageFormat.format(extras, args);
118                    
119                    result.append( "<br />" );
120                    result.append( "<a class='morelink' href='"+context.getURL( WikiContext.INFO, page.getName() )+"' ");
121                    result.append( ">"+extras+"</a><br />");
122                }
123            }
124
125            //
126            // If nothing was left after filtering or during search
127            //
128            if (links == null || links.size() == 0)
129            {
130                wikitext = rb.getString("referringpagesplugin.nobody");
131                
132                result.append( makeHTML( context, wikitext ) );
133            }
134            else
135            {
136                if( m_show.equals( PARAM_SHOW_VALUE_COUNT ) )
137                {
138                    result = new StringBuilder();
139                    result.append( links.size() );
140                    if( m_lastModified )
141                    {
142                        result.append( " (" + m_dateFormat.format( m_dateLastModified ) + ")" );
143                    }
144                }
145            }
146            
147            return result.toString();
148        }
149
150        return "";
151    }
152
153}