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.rss;
020
021import org.apache.commons.text.StringEscapeUtils;
022import org.apache.wiki.api.core.Context;
023import org.apache.wiki.api.core.Engine;
024import org.apache.wiki.api.exceptions.NoSuchVariableException;
025import org.apache.wiki.variables.VariableManager;
026
027import javax.servlet.ServletContext;
028import java.util.ArrayList;
029import java.util.List;
030
031/**
032 * Represents an abstract feed.
033 */
034public abstract class Feed {
035    protected final List<Entry> m_entries = new ArrayList<>();
036
037    protected String m_feedURL;
038    protected String m_channelTitle;
039    protected String m_channelDescription;
040    protected String m_channelLanguage;
041
042    protected final Context m_wikiContext;
043
044    protected String m_mode = RSSGenerator.MODE_WIKI;
045
046    /**
047     * Wiki variable storing the blog's name.
048     */
049    public static final String VAR_BLOGNAME = "blogname";
050
051    /**
052     * Figure out a site name for a feed.
053     *
054     * @param context the wiki context
055     * @return the site name
056     */
057    public static String getSiteName( final Context context ) {
058        final Engine engine = context.getEngine();
059
060        String blogname = null;
061
062        try {
063            blogname = engine.getManager( VariableManager.class ).getValue(context, VAR_BLOGNAME);
064        } catch( final NoSuchVariableException e ) {
065        }
066
067        if (blogname == null) {
068            blogname = engine.getApplicationName() + ": " + context.getPage().getName();
069        }
070
071        return blogname;
072    }
073
074    /**
075     * Create a new Feed for a particular WikiContext.
076     *
077     * @param context The WikiContext.
078     */
079    public Feed( final Context context) {
080        m_wikiContext = context;
081    }
082
083    /**
084     * Set the mode of the Feed.  It can be any of the following:
085     * <ul>
086     * <li>{@link RSSGenerator#MODE_WIKI} - to create a wiki diff list per page.</li>
087     * <li>{@link RSSGenerator#MODE_BLOG} - to assume that the Entries are blog entries.</li>
088     * <li>{@link RSSGenerator#MODE_FULL} - to create a wiki diff list for the entire blog.</li>
089     * </ul>
090     * As the Entry list itself is generated elsewhere, this mostly just affects the way
091     * that the layout and metadata for each entry is generated.
092     *
093     * @param mode As defined in RSSGenerator.
094     */
095    public void setMode( final String mode) {
096        m_mode = mode;
097    }
098
099    /**
100     * Adds a new Entry to the Feed, at the end of the list.
101     *
102     * @param e The Entry to add.
103     */
104    public void addEntry( final Entry e) {
105        m_entries.add(e);
106    }
107
108    /**
109     * Returns the XML for the feed contents in a String format.  All subclasses must implement.
110     *
111     * @return valid XML, ready to be shoved out.
112     */
113    public abstract String getString();
114
115    /**
116     * @return Returns the m_channelDescription.
117     */
118    public String getChannelDescription() {
119        return m_channelDescription;
120    }
121
122    /**
123     * @param description The m_channelDescription to set.
124     */
125    public void setChannelDescription( final String description) {
126        m_channelDescription = description;
127    }
128
129    /**
130     * @return Returns the m_channelLanguage.
131     */
132    public String getChannelLanguage() {
133        return m_channelLanguage;
134    }
135
136    /**
137     * @param language The m_channelLanguage to set.
138     */
139    public void setChannelLanguage( final String language) {
140        m_channelLanguage = language;
141    }
142
143    /**
144     * @return Returns the m_channelTitle.
145     */
146    public String getChannelTitle() {
147        return m_channelTitle;
148    }
149
150    /**
151     * @param title The m_channelTitle to set.
152     */
153    public void setChannelTitle( final String title) {
154        m_channelTitle = title;
155    }
156
157    /**
158     * @return Returns the m_feedURL.
159     */
160    public String getFeedURL() {
161        return m_feedURL;
162    }
163
164    /**
165     * @param feedurl The m_feedURL to set.
166     */
167    public void setFeedURL( final String feedurl) {
168        m_feedURL = feedurl;
169    }
170
171    /**
172     * A helper method for figuring out the MIME type for an enclosure.
173     *
174     * @param c    A ServletContext
175     * @param name The filename
176     * @return Something sane for a MIME type.
177     */
178    protected String getMimeType( final ServletContext c, final String name) {
179        String type = c.getMimeType(name);
180
181        if (type == null) {
182            type = "application/octet-stream";
183        }
184
185        return type;
186    }
187
188    /**
189     * Does the required formatting and entity replacement for XML.
190     *
191     * @param s The String to format. Null is safe.
192     * @return A formatted string.
193     */
194    public static String format( final String s ) {
195        return StringEscapeUtils.escapeXml11( s );
196    }
197}