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