2 * Copyright (C) 2001, 2002 The Mir-coders group
4 * This file is part of Mir.
6 * Mir is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * Mir is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with Mir; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 * In addition, as a special exception, The Mir-coders gives permission to link
21 * the code of this program with the com.oreilly.servlet library, any library
22 * licensed under the Apache Software License, The Sun (tm) Java Advanced
23 * Imaging library (JAI), The Sun JIMI library (or with modified versions of
24 * the above that use the same license as the above), and distribute linked
25 * combinations including the two. You must obey the GNU General Public
26 * License in all respects for all of the code used other than the above
27 * mentioned libraries. If you modify this file, you may extend this exception
28 * to your version of the file, but you are not obligated to do so. If you do
29 * not wish to do so, delete this exception statement from your version.
36 import freemarker.template.SimpleList;
41 * Interface for Media handling in Mir. All media handlers
42 * must implement this interface. Each specific media type,
43 * be it Gif, Jpeg, Mp3 audio, Real Audio or quicktime video
44 * has special needs when it comes to representation on the various
45 * pages (article, list, summary), must be stored differently and has a
46 * different URL, etc... This interface allows Mir to support
47 * an infinite (I hope) number of media types. Once this is done,
48 * no code at any other level in Mir needs to be changed other than
49 * adding the content-type <-> media handler name mapping in the
50 * media_type table. The following is an example of the media_type
53 * id | name | mime_type | classname | tablename | dcname<br>
54 *---+---------+--------------------------+-----------+---------------+-------<br>
55 * 2 | unknown | application/octet-stream | -- | UploadedMedia | <br>
56 * 3 | jpg | image/gif | ImagesGif | Images | <br>
57 * 4 | mp3 | audio/mp3 | Audio | UploadedMedia | <br>
59 * The "id" field is used as a mapping in the table that contains the media type
60 * to the media_type table. For example, the images table has a to_media_type
61 * field that contains the id in the media_type table.
63 * The "name" field is used for various display/filenaming purposes. it should
64 * match a valid file extension name for a media_type (we could have used the
65 * content-type map for this....).
67 * The "mime_type" field is the most important as it does maps the type to Java
68 * classes (the storage and media_handler name). We call those classes using
69 * reflection. This way, once a Handler for a specific media type is implemented
70 * and entered into the media_type table, no other Mir code needs to be modified.
72 * The "classname" field is the name of the media handler (e.g MediaHandlerAudio)
73 * we use it to call the MediaHandler methods via reflection.
75 * The "tablename" is the name of the database storage classes (e.g DatabaseImages
76 * and EntityImages). We use this to fetch/storage the media (meta)data in the db.
78 * The "dcname" field is as of yet unused. Do search for "Dublin Core" on google
81 * Most media handlers should just extend MediaHandlerGeneric (i.e inherit from
82 * ) and just override the things that need to be specific. see MediaHandlerAudio
84 * @author mh <heckmann@hbe.ca>
88 public interface MirMedia{
91 * Takes the uploaded media data itself, along with the media Entity
92 * which contains the Media metadata plus the MediaType entity containing
93 * all the info for the specific media type itself. It's job is store the
94 * Media data (content) itself, this could be on the local filesystem, in the
95 * DB or even on a remote host. It then inserts the MetaData in the DB.
96 * @param uploadedData, a byte array containing the uploaded data.
97 * @param ent, an Entity holding the media MetaData
98 * @param mediaType, an Entity holding the media_table entry
99 * @return boolean, success/fail
100 * @see mir.entity.Entity
102 public abstract boolean set (byte[] uploadedData, Entity ent,
103 Entity mediaTypeEnt ) throws MirMediaException;
105 public abstract void produce (Entity ent, Entity mediaTypeEnt )
106 throws MirMediaException;
109 * Get's the media data from storage and returns it as a byte array
110 * Not very useful for most media types as they are stored in a file,
111 * but very usefull for ones stored in the DB as it is necessary to get
112 * it first before making a file out of it (in Producer*).
113 * @param ent, an Entity holding the media MetaData
114 * @param mediaType, an Entity holding the media_table entry
116 * @see mir.entity.Entity
118 public abstract byte[] get (Entity ent, Entity mediaTypeEnt)
119 throws MirMediaException;
122 * Pretty much like get() above. But get's the specific Icon
123 * representation. useful for media stored in the DB.
124 * @param ent, an Entity holding the media MetaData
126 * @see mir.entity.Entity
128 public abstract byte[] getIcon (Entity ent) throws MirMediaException;
131 * gets the final content representation for the media
132 * in the form of a URL (String) that allows someone to
133 * download, look at or listen to the media. (HREF, img src
134 * streaming link, etc..)
135 * It should use the helper functions in the StringUtil class to
136 * build URL's safely, eliminating any *illegal* user input.
137 * @param ent, an Entity holding the media MetaData
138 * @param mediaTypeEnt, an Entity holding the media_table entry
139 * @return String, the url.
140 * @see mir.entity.Entity
141 * @see mir.misc.StringUtil
143 public abstract SimpleList getURL (Entity ent, Entity mediaTypeEnt)
144 throws MirMediaException;
147 * Returns the absolute filesystem path to where the media
148 * content should be stored. This path is usually defined
149 * in the configuration wich is accessible through the MirConfig
151 * @return String, the path.
152 * @see mir.misc.MirConfig
154 public abstract String getStoragePath () throws MirMediaException;
157 * Returns the *relative* filesystem path to where the media
158 * icon content should be stored. It is relative to the path
159 * returned by getStoragePath()
160 * This path is usually defined
161 * in the configuration wich is accessible through the MirConfig
163 * @return String, the path.
164 * @see mir.misc.MirConfig
166 public abstract String getIconStoragePath () throws MirMediaException;
169 * Returns the base URL to that the media is accessible from
170 * to the end user. This could be a URL to another host.
171 * This is used in the Metadata stored in the DB and later on
172 * ,the templates use it.
173 * It is usually defined
174 * in the configuration witch is accessible through the MirConfig
176 * @return String, the base URL to the host.
177 * @see mir.misc.MirConfig
179 public abstract String getPublishHost () throws MirMediaException;
182 * Returns the file name of the Icon representing the media type.
183 * It is used in the summary view.
184 * It is usually defined
185 * in the configuration wich is accessible through the MirConfig
187 * @return String, the icon filename.
188 * @see mir.misc.MirConfig
190 public abstract String getBigIcon ();
193 * Returns the file name of the small Icon representing
195 * It is used in the right hand newswire list of the startpage.
196 * It is usually defined
197 * in the configuration wich is accessible through the MirConfig
199 * @return String, the icon filename.
200 * @see mir.misc.MirConfig
202 public abstract String getTinyIcon ();
205 * Returns the IMG SRC "ALT" text to be used
206 * for the Icon representations
207 * @return String, the ALT text.
209 public abstract String getIconAlt ();
212 * your can all figure it out.
215 public abstract boolean isVideo ();
218 * you can all figure it out.
221 public abstract boolean isAudio ();
224 * you can all figure it out.
227 public abstract boolean isImage ();
230 * returns a brief text dscription of what this
234 public abstract String getDescr (Entity mediaTypeEnt);