001/**
002 * Copyright 2011 Bill Brown
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package com.colorfulsoftware.rss;
017
018import java.io.Serializable;
019
020/**
021 * <p>
022 * The &lt;source> element.
023 * </p>
024 * <p>
025 * From the <a href="http://cyber.law.harvard.edu/rss/rss.html">RSS 2.0
026 * specification</a>...
027 * </p>
028 * <p>
029 * The RSS channel that the item came from. <a href=
030 * "http://cyber.law.harvard.edu/rss/rss.html#ltsourcegtSubelementOfLtitemgt"
031 * >More</a>.
032 * </p>
033 * 
034 * <p>
035 * &lt;source> is an optional sub-element of &lt;item>.
036 * </p>
037 * 
038 * <p>
039 * Its value is the name of the RSS channel that the item came from, derived
040 * from its &lt;title>. It has one required attribute, url, which links to the
041 * XMLization of the source.
042 * </p>
043 * 
044 * <p>
045 * &lt;source url="http://www.tomalak.org/links2.xml">Tomalak's
046 * Realm&lt;/source>
047 * </p>
048 * 
049 * <p>
050 * The purpose of this element is to propagate credit for links, to publicize
051 * the sources of news items. It can be used in the Post command of an
052 * aggregator. It should be generated automatically when forwarding an item from
053 * an aggregator to a weblog authoring tool.
054 * </p>
055 * 
056 * @author Bill Brown
057 * 
058 */
059public class Source implements Serializable {
060
061        /**
062         * 
063         */
064        private static final long serialVersionUID = -4585022053173517802L;
065
066        private final String source;
067        private final Attribute url;
068
069        Source(Attribute url, String source) throws RSSpectException {
070                // make sure the url attribute is present
071                if (url == null || !url.getName().equals("url")) {
072                        throw new RSSpectException(
073                                        "source elements MUST contain a url attribute.");
074                }
075                this.url = new Attribute(url.getName(), url.getValue());
076
077                if (source == null || source.equals("")) {
078                        throw new RSSpectException("source SHOULD NOT be blank.");
079                }
080                this.source = source;
081        }
082
083        Source(Source source) {
084                this.url = source.getUrl();
085                this.source = source.source;
086        }
087
088        /**
089         * @return the url attribute.
090         */
091        public Attribute getUrl() {
092                return new Attribute(url);
093        }
094
095        /**
096         * @return the source data.
097         */
098        public String getSource() {
099                return source;
100        }
101
102        /**
103         * Shows the contents of the &lt;source> element.
104         */
105        @Override
106        public String toString() {
107                return "<source" + url + " >" + source + "</source>";
108        }
109        
110        @Override
111        public boolean equals(Object obj) {
112                if (obj == this) {
113                        return true;
114                }
115                if (!(obj instanceof Source)) {
116                        return false;
117                }
118                return this.toString().equals(obj.toString());
119        }
120        
121        @Override public int hashCode() {
122                return toString().hashCode();
123        }
124
125}