includes/Feed.php

   1 <?php
   2 /**
   3  * Basic support for outputting syndication feeds in RSS, other formats.
   4  *
   5  * Contain a feed class as well as classes to build rss / atom ... feeds
   6  * Available feeds are defined in Defines.php
   7  *
   8  * Copyright © 2004 Brion Vibber <brion@pobox.com>
   9  * http://www.mediawiki.org/
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  24  * http://www.gnu.org/copyleft/gpl.html
  25  *
  26  * @file
  27  */
  28
  29 /**
  30  * @defgroup Feed Feed
  31  */
  32
  33 /**
  34  * A base class for basic support for outputting syndication feeds in RSS and other formats.
  35  *
  36  * @ingroup Feed
  37  */
  38 class FeedItem {
  39         /**
  40          * @var Title
  41          */
  42         var $Title = 'Wiki';
  43         var $Description = '';
  44         var $Url = '';
  45         var $Date = '';
  46         var $Author = '';
  47         var $UniqueId = '';
  48         var $RSSIsPermalink;
  49
  50         /**
  51          * Constructor
  52          *
  53          * @param $Title String|Title Item's title
  54          * @param $Description String
  55          * @param $Url String: URL uniquely designating the item.
  56          * @param $Date String: Item's date
  57          * @param $Author String: Author's user name
  58          * @param $Comments String
  59          */
  60         function __construct( $Title, $Description, $Url, $Date = '', $Author = '', $Comments = '' ) {
  61                 $this->Title = $Title;
  62                 $this->Description = $Description;
  63                 $this->Url = $Url;
  64                 $this->UniqueId = $Url;
  65                 $this->RSSIsPermalink = false;
  66                 $this->Date = $Date;
  67                 $this->Author = $Author;
  68                 $this->Comments = $Comments;
  69         }
  70
  71         /**
  72          * Get the last touched timestamp
  73          *
  74          * @return String last-touched timestamp
  75          */
  76         public function getLastMod() {
  77                 return $this->Title->getTouched();
  78         }
  79
  80         /**
  81          * Encode $string so that it can be safely embedded in a XML document
  82          *
  83          * @param $string String: string to encode
  84          * @return String
  85          */
  86         public function xmlEncode( $string ) {
  87                 $string = str_replace( "\r\n", "\n", $string );
  88                 $string = preg_replace( '/[\x00-\x08\x0b\x0c\x0e-\x1f]/', '', $string );
  89                 return htmlspecialchars( $string );
  90         }
  91
  92         /**
  93          * Get the unique id of this item
  94          *
  95          * @return String
  96          */
  97         public function getUniqueId() {
  98                 if ( $this->UniqueId ) {
  99                         return $this->xmlEncode( $this->UniqueId );
 100                 }
 101         }
 102
 103         /**
 104          * set the unique id of an item
 105          *
 106          * @param $uniqueId String: unique id for the item
 107          * @param $RSSisPermalink Boolean: set to true if the guid (unique id) is a permalink (RSS feeds only)
 108          */
 109         public function setUniqueId($uniqueId, $RSSisPermalink = false) {
 110                 $this->UniqueId = $uniqueId;
 111                 $this->RSSIsPermalink = $RSSisPermalink;
 112         }
 113
 114         /**
 115          * Get the title of this item; already xml-encoded
 116          *
 117          * @return String
 118          */
 119         public function getTitle() {
 120                 return $this->xmlEncode( $this->Title );
 121         }
 122
 123         /**
 124          * Get the DB prefixed title
 125          *
 126          * @return String the prefixed title, with underscores and
 127          *  any interwiki and namespace prefixes
 128          */
 129         public function getDBPrefixedTitle() {
 130                 return $this->Title->getPrefixedDBKey();
 131         }
 132
 133         /**
 134          * Get the URL of this item; already xml-encoded
 135          *
 136          * @return String
 137          */
 138         public function getUrl() {
 139                 return $this->xmlEncode( $this->Url );
 140         }
 141
 142         /**
 143          * Get the description of this item; already xml-encoded
 144          *
 145          * @return String
 146          */
 147         public function getDescription() {
 148                 return $this->xmlEncode( $this->Description );
 149         }
 150
 151         /**
 152          * Get the language of this item
 153          *
 154          * @return String
 155          */
 156         public function getLanguage() {
 157                 global $wgLanguageCode;
 158                 return $wgLanguageCode;
 159         }
 160
 161         /**
 162          * Get the title of this item
 163          *
 164          * @return String
 165          */
 166         public function getDate() {
 167                 return $this->Date;
 168         }
 169
 170         /**
 171          * Get the author of this item; already xml-encoded
 172          *
 173          * @return String
 174          */
 175         public function getAuthor() {
 176                 return $this->xmlEncode( $this->Author );
 177         }
 178
 179         /**
 180          * Get the comment of this item; already xml-encoded
 181          *
 182          * @return String
 183          */
 184         public function getComments() {
 185                 return $this->xmlEncode( $this->Comments );
 186         }
 187
 188         /**
 189          * Quickie hack... strip out wikilinks to more legible form from the comment.
 190          *
 191          * @param $text String: wikitext
 192          * @return String
 193          */
 194         public static function stripComment( $text ) {
 195                 return preg_replace( '/\[\[([^]]*\|)?([^]]+)\]\]/', '\2', $text );
 196         }
 197         /**#@-*/
 198 }
 199
 200 /**
 201  * @todo document (needs one-sentence top-level class description).
 202  * @ingroup Feed
 203  */
 204 class ChannelFeed extends FeedItem {
 205         /**#@+
 206          * Abstract function, override!
 207          * @abstract
 208          */
 209
 210         /**
 211          * Generate Header of the feed
 212          */
 213         function outHeader() {
 214                 # print "<feed>";
 215         }
 216
 217         /**
 218          * Generate an item
 219          * @param $item
 220          */
 221         function outItem( $item ) {
 222                 # print "<item>...</item>";
 223         }
 224
 225         /**
 226          * Generate Footer of the feed
 227          */
 228         function outFooter() {
 229                 # print "</feed>";
 230         }
 231         /**#@-*/
 232
 233         /**
 234          * Setup and send HTTP headers. Don't send any content;
 235          * content might end up being cached and re-sent with
 236          * these same headers later.
 237          *
 238          * This should be called from the outHeader() method,
 239          * but can also be called separately.
 240          */
 241         public function httpHeaders() {
 242                 global $wgOut;
 243
 244                 # We take over from $wgOut, excepting its cache header info
 245                 $wgOut->disable();
 246                 $mimetype = $this->contentType();
 247                 header( "Content-type: $mimetype; charset=UTF-8" );
 248                 $wgOut->sendCacheControl();
 249
 250         }
 251
 252         /**
 253          * Return an internet media type to be sent in the headers.
 254          *
 255          * @return string
 256          * @private
 257          */
 258         function contentType() {
 259                 global $wgRequest;
 260                 $ctype = $wgRequest->getVal('ctype','application/xml');
 261                 $allowedctypes = array('application/xml','text/xml','application/rss+xml','application/atom+xml');
 262                 return (in_array($ctype, $allowedctypes) ? $ctype : 'application/xml');
 263         }
 264
 265         /**
 266          * Output the initial XML headers with a stylesheet for legibility
 267          * if someone finds it in a browser.
 268          * @private
 269          */
 270         function outXmlHeader() {
 271                 global $wgStylePath, $wgStyleVersion;
 272
 273                 $this->httpHeaders();
 274                 echo '<?xml version="1.0"?>' . "\n";
 275                 echo '<?xml-stylesheet type="text/css" href="' .
 276                         htmlspecialchars( wfExpandUrl( "$wgStylePath/common/feed.css?$wgStyleVersion" ) ) .
 277                         '"?' . ">\n";
 278         }
 279 }
 280
 281 /**
 282  * Generate a RSS feed
 283  *
 284  * @ingroup Feed
 285  */
 286 class RSSFeed extends ChannelFeed {
 287
 288         /**
 289          * Format a date given a timestamp
 290          *
 291          * @param $ts Integer: timestamp
 292          * @return String: date string
 293          */
 294         function formatTime( $ts ) {
 295                 return gmdate( 'D, d M Y H:i:s \G\M\T', wfTimestamp( TS_UNIX, $ts ) );
 296         }
 297
 298         /**
 299          * Ouput an RSS 2.0 header
 300          */
 301         function outHeader() {
 302                 global $wgVersion;
 303
 304                 $this->outXmlHeader();
 305                 ?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
 306         <channel>
 307                 <title><?php print $this->getTitle() ?></title>
 308                 <link><?php print $this->getUrl() ?></link>
 309                 <description><?php print $this->getDescription() ?></description>
 310                 <language><?php print $this->getLanguage() ?></language>
 311                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 312                 <lastBuildDate><?php print $this->formatTime( wfTimestampNow() ) ?></lastBuildDate>
 313 <?php
 314         }
 315
 316         /**
 317          * Output an RSS 2.0 item
 318          * @param $item FeedItem: item to be output
 319          */
 320         function outItem( $item ) {
 321         ?>
 322                 <item>
 323                         <title><?php print $item->getTitle() ?></title>
 324                         <link><?php print $item->getUrl() ?></link>
 325                         <guid<?php if( !$item->RSSIsPermalink ) print ' isPermaLink="false"' ?>><?php print $item->getUniqueId() ?></guid>
 326                         <description><?php print $item->getDescription() ?></description>
 327                         <?php if( $item->getDate() ) { ?><pubDate><?php print $this->formatTime( $item->getDate() ) ?></pubDate><?php } ?>
 328                         <?php if( $item->getAuthor() ) { ?><dc:creator><?php print $item->getAuthor() ?></dc:creator><?php }?>
 329                         <?php if( $item->getComments() ) { ?><comments><?php print $item->getComments() ?></comments><?php }?>
 330                 </item>
 331 <?php
 332         }
 333
 334         /**
 335          * Ouput an RSS 2.0 footer
 336          */
 337         function outFooter() {
 338         ?>
 339         </channel>
 340 </rss><?php
 341         }
 342 }
 343
 344 /**
 345  * Generate an Atom feed
 346  *
 347  * @ingroup Feed
 348  */
 349 class AtomFeed extends ChannelFeed {
 350         /**
 351          * @todo document
 352          */
 353         function formatTime( $ts ) {
 354                 // need to use RFC 822 time format at least for rss2.0
 355                 return gmdate( 'Y-m-d\TH:i:s', wfTimestamp( TS_UNIX, $ts ) );
 356         }
 357
 358         /**
 359          * Outputs a basic header for Atom 1.0 feeds.
 360          */
 361         function outHeader() {
 362                 global $wgVersion;
 363
 364                 $this->outXmlHeader();
 365                 ?><feed xmlns="http://www.w3.org/2005/Atom" xml:lang="<?php print $this->getLanguage() ?>">
 366                 <id><?php print $this->getFeedId() ?></id>
 367                 <title><?php print $this->getTitle() ?></title>
 368                 <link rel="self" type="application/atom+xml" href="<?php print $this->getSelfUrl() ?>"/>
 369                 <link rel="alternate" type="text/html" href="<?php print $this->getUrl() ?>"/>
 370                 <updated><?php print $this->formatTime( wfTimestampNow() ) ?>Z</updated>
 371                 <subtitle><?php print $this->getDescription() ?></subtitle>
 372                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 373
 374 <?php
 375         }
 376
 377         /**
 378          * Atom 1.0 requires a unique, opaque IRI as a unique indentifier
 379          * for every feed we create. For now just use the URL, but who
 380          * can tell if that's right? If we put options on the feed, do we
 381          * have to change the id? Maybe? Maybe not.
 382          *
 383          * @return string
 384          * @private
 385          */
 386         function getFeedId() {
 387                 return $this->getSelfUrl();
 388         }
 389
 390         /**
 391          * Atom 1.0 requests a self-reference to the feed.
 392          * @return string
 393          * @private
 394          */
 395         function getSelfUrl() {
 396                 global $wgRequest;
 397                 return htmlspecialchars( $wgRequest->getFullRequestURL() );
 398         }
 399
 400         /**
 401          * Output a given item.
 402          * @param $item
 403          */
 404         function outItem( $item ) {
 405                 global $wgMimeType;
 406         ?>
 407         <entry>
 408                 <id><?php print $item->getUniqueId() ?></id>
 409                 <title><?php print $item->getTitle() ?></title>
 410                 <link rel="alternate" type="<?php print $wgMimeType ?>" href="<?php print $item->getUrl() ?>"/>
 411                 <?php if( $item->getDate() ) { ?>
 412                 <updated><?php print $this->formatTime( $item->getDate() ) ?>Z</updated>
 413                 <?php } ?>
 414
 415                 <summary type="html"><?php print $item->getDescription() ?></summary>
 416                 <?php if( $item->getAuthor() ) { ?><author><name><?php print $item->getAuthor() ?></name></author><?php }?>
 417         </entry>
 418
 419 <?php /* @todo FIXME: Need to add comments
 420         <?php if( $item->getComments() ) { ?><dc:comment><?php print $item->getComments() ?></dc:comment><?php }?>
 421           */
 422         }
 423
 424         /**
 425          * Outputs the footer for Atom 1.0 feed (basicly '\</feed\>').
 426          */
 427         function outFooter() {?>
 428         </feed><?php
 429         }
 430 }