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 string
  41          * @private
  42          */
  43         var $Title = 'Wiki';
  44         var $Description = '';
  45         var $Url = '';
  46         var $Date = '';
  47         var $Author = '';
  48         var $UniqueId = '';
  49         var $RSSIsPermalink;
  50         /**#@-*/
  51
  52         /**
  53          * Constructor
  54          *
  55          * @param $Title String: Item's title
  56          * @param $Description String
  57          * @param $Url String: URL uniquely designating the item.
  58          * @param $Date String: Item's date
  59          * @param $Author String: Author's user name
  60          * @param $Comments String
  61          */
  62         function __construct( $Title, $Description, $Url, $Date = '', $Author = '', $Comments = '' ) {
  63                 $this->Title = $Title;
  64                 $this->Description = $Description;
  65                 $this->Url = $Url;
  66                 $this->UniqueId = $Url;
  67                 $this->RSSIsPermalink = false;
  68                 $this->Date = $Date;
  69                 $this->Author = $Author;
  70                 $this->Comments = $Comments;
  71         }
  72
  73         /**
  74          * Get the last touched timestamp
  75          *
  76          * @return String last-touched timestamp
  77          */
  78         public function getLastMod() {
  79                 return $this->Title->getTouched();
  80         }
  81
  82         /**
  83          * Encode $string so that it can be safely embedded in a XML document
  84          *
  85          * @param $string String: string to encode
  86          * @return String
  87          */
  88         public function xmlEncode( $string ) {
  89                 $string = str_replace( "\r\n", "\n", $string );
  90                 $string = preg_replace( '/[\x00-\x08\x0b\x0c\x0e-\x1f]/', '', $string );
  91                 return htmlspecialchars( $string );
  92         }
  93
  94         /**
  95          * Get the unique id of this item
  96          *
  97          * @return String
  98          */
  99         public function getUniqueId() {
 100                 if ( $this->UniqueId ) {
 101                         return $this->xmlEncode( $this->UniqueId );
 102                 }
 103         }
 104
 105         /**
 106          * set the unique id of an item
 107          *
 108          * @param $uniqueId String: unique id for the item
 109          * @param $RSSisPermalink Boolean: set to true if the guid (unique id) is a permalink (RSS feeds only)
 110          */
 111         public function setUniqueId($uniqueId, $RSSisPermalink = false) {
 112                 $this->UniqueId = $uniqueId;
 113                 $this->RSSIsPermalink = $RSSisPermalink;
 114         }
 115
 116         /**
 117          * Get the title of this item; already xml-encoded
 118          *
 119          * @return String
 120          */
 121         public function getTitle() {
 122                 return $this->xmlEncode( $this->Title );
 123         }
 124
 125         /**
 126          * Get the DB prefixed title
 127          *
 128          * @return String the prefixed title, with underscores and
 129          *  any interwiki and namespace prefixes
 130          */
 131         public function getDBPrefixedTitle() {
 132                 return $this->Title->getPrefixedDBKey();
 133         }
 134
 135         /**
 136          * Get the URL of this item; already xml-encoded
 137          *
 138          * @return String
 139          */
 140         public function getUrl() {
 141                 return $this->xmlEncode( $this->Url );
 142         }
 143
 144         /**
 145          * Get the description of this item; already xml-encoded
 146          *
 147          * @return String
 148          */
 149         public function getDescription() {
 150                 return $this->xmlEncode( $this->Description );
 151         }
 152
 153         /**
 154          * Get the language of this item
 155          *
 156          * @return String
 157          */
 158         public function getLanguage() {
 159                 global $wgLanguageCode;
 160                 return $wgLanguageCode;
 161         }
 162
 163         /**
 164          * Get the title of this item
 165          *
 166          * @return String
 167          */
 168         public function getDate() {
 169                 return $this->Date;
 170         }
 171
 172         /**
 173          * Get the author of this item; already xml-encoded
 174          *
 175          * @return String
 176          */
 177         public function getAuthor() {
 178                 return $this->xmlEncode( $this->Author );
 179         }
 180
 181         /**
 182          * Get the comment of this item; already xml-encoded
 183          *
 184          * @return String
 185          */
 186         public function getComments() {
 187                 return $this->xmlEncode( $this->Comments );
 188         }
 189
 190         /**
 191          * Quickie hack... strip out wikilinks to more legible form from the comment.
 192          *
 193          * @param $text String: wikitext
 194          * @return String
 195          */
 196         public static function stripComment( $text ) {
 197                 return preg_replace( '/\[\[([^]]*\|)?([^]]+)\]\]/', '\2', $text );
 198         }
 199         /**#@-*/
 200 }
 201
 202 /**
 203  * @todo document (needs one-sentence top-level class description).
 204  * @ingroup Feed
 205  */
 206 class ChannelFeed extends FeedItem {
 207         /**#@+
 208          * Abstract function, override!
 209          * @abstract
 210          */
 211
 212         /**
 213          * Generate Header of the feed
 214          */
 215         function outHeader() {
 216                 # print "<feed>";
 217         }
 218
 219         /**
 220          * Generate an item
 221          * @param $item
 222          */
 223         function outItem( $item ) {
 224                 # print "<item>...</item>";
 225         }
 226
 227         /**
 228          * Generate Footer of the feed
 229          */
 230         function outFooter() {
 231                 # print "</feed>";
 232         }
 233         /**#@-*/
 234
 235         /**
 236          * Setup and send HTTP headers. Don't send any content;
 237          * content might end up being cached and re-sent with
 238          * these same headers later.
 239          *
 240          * This should be called from the outHeader() method,
 241          * but can also be called separately.
 242          */
 243         public function httpHeaders() {
 244                 global $wgOut;
 245
 246                 # We take over from $wgOut, excepting its cache header info
 247                 $wgOut->disable();
 248                 $mimetype = $this->contentType();
 249                 header( "Content-type: $mimetype; charset=UTF-8" );
 250                 $wgOut->sendCacheControl();
 251
 252         }
 253
 254         /**
 255          * Return an internet media type to be sent in the headers.
 256          *
 257          * @return string
 258          * @private
 259          */
 260         function contentType() {
 261                 global $wgRequest;
 262                 $ctype = $wgRequest->getVal('ctype','application/xml');
 263                 $allowedctypes = array('application/xml','text/xml','application/rss+xml','application/atom+xml');
 264                 return (in_array($ctype, $allowedctypes) ? $ctype : 'application/xml');
 265         }
 266
 267         /**
 268          * Output the initial XML headers with a stylesheet for legibility
 269          * if someone finds it in a browser.
 270          * @private
 271          */
 272         function outXmlHeader() {
 273                 global $wgStylePath, $wgStyleVersion;
 274
 275                 $this->httpHeaders();
 276                 echo '<?xml version="1.0"?>' . "\n";
 277                 echo '<?xml-stylesheet type="text/css" href="' .
 278                         htmlspecialchars( wfExpandUrl( "$wgStylePath/common/feed.css?$wgStyleVersion" ) ) .
 279                         '"?' . ">\n";
 280         }
 281 }
 282
 283 /**
 284  * Generate a RSS feed
 285  *
 286  * @ingroup Feed
 287  */
 288 class RSSFeed extends ChannelFeed {
 289
 290         /**
 291          * Format a date given a timestamp
 292          *
 293          * @param $ts Integer: timestamp
 294          * @return String: date string
 295          */
 296         function formatTime( $ts ) {
 297                 return gmdate( 'D, d M Y H:i:s \G\M\T', wfTimestamp( TS_UNIX, $ts ) );
 298         }
 299
 300         /**
 301          * Ouput an RSS 2.0 header
 302          */
 303         function outHeader() {
 304                 global $wgVersion;
 305
 306                 $this->outXmlHeader();
 307                 ?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
 308         <channel>
 309                 <title><?php print $this->getTitle() ?></title>
 310                 <link><?php print $this->getUrl() ?></link>
 311                 <description><?php print $this->getDescription() ?></description>
 312                 <language><?php print $this->getLanguage() ?></language>
 313                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 314                 <lastBuildDate><?php print $this->formatTime( wfTimestampNow() ) ?></lastBuildDate>
 315 <?php
 316         }
 317
 318         /**
 319          * Output an RSS 2.0 item
 320          * @param $item FeedItem: item to be output
 321          */
 322         function outItem( $item ) {
 323         ?>
 324                 <item>
 325                         <title><?php print $item->getTitle() ?></title>
 326                         <link><?php print $item->getUrl() ?></link>
 327                         <guid<?php if( !$item->RSSIsPermalink ) print ' isPermaLink="false"' ?>><?php print $item->getUniqueId() ?></guid>
 328                         <description><?php print $item->getDescription() ?></description>
 329                         <?php if( $item->getDate() ) { ?><pubDate><?php print $this->formatTime( $item->getDate() ) ?></pubDate><?php } ?>
 330                         <?php if( $item->getAuthor() ) { ?><dc:creator><?php print $item->getAuthor() ?></dc:creator><?php }?>
 331                         <?php if( $item->getComments() ) { ?><comments><?php print $item->getComments() ?></comments><?php }?>
 332                 </item>
 333 <?php
 334         }
 335
 336         /**
 337          * Ouput an RSS 2.0 footer
 338          */
 339         function outFooter() {
 340         ?>
 341         </channel>
 342 </rss><?php
 343         }
 344 }
 345
 346 /**
 347  * Generate an Atom feed
 348  *
 349  * @ingroup Feed
 350  */
 351 class AtomFeed extends ChannelFeed {
 352         /**
 353          * @todo document
 354          */
 355         function formatTime( $ts ) {
 356                 // need to use RFC 822 time format at least for rss2.0
 357                 return gmdate( 'Y-m-d\TH:i:s', wfTimestamp( TS_UNIX, $ts ) );
 358         }
 359
 360         /**
 361          * Outputs a basic header for Atom 1.0 feeds.
 362          */
 363         function outHeader() {
 364                 global $wgVersion;
 365
 366                 $this->outXmlHeader();
 367                 ?><feed xmlns="http://www.w3.org/2005/Atom" xml:lang="<?php print $this->getLanguage() ?>">
 368                 <id><?php print $this->getFeedId() ?></id>
 369                 <title><?php print $this->getTitle() ?></title>
 370                 <link rel="self" type="application/atom+xml" href="<?php print $this->getSelfUrl() ?>"/>
 371                 <link rel="alternate" type="text/html" href="<?php print $this->getUrl() ?>"/>
 372                 <updated><?php print $this->formatTime( wfTimestampNow() ) ?>Z</updated>
 373                 <subtitle><?php print $this->getDescription() ?></subtitle>
 374                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 375
 376 <?php
 377         }
 378
 379         /**
 380          * Atom 1.0 requires a unique, opaque IRI as a unique indentifier
 381          * for every feed we create. For now just use the URL, but who
 382          * can tell if that's right? If we put options on the feed, do we
 383          * have to change the id? Maybe? Maybe not.
 384          *
 385          * @return string
 386          * @private
 387          */
 388         function getFeedId() {
 389                 return $this->getSelfUrl();
 390         }
 391
 392         /**
 393          * Atom 1.0 requests a self-reference to the feed.
 394          * @return string
 395          * @private
 396          */
 397         function getSelfUrl() {
 398                 global $wgRequest;
 399                 return htmlspecialchars( $wgRequest->getFullRequestURL() );
 400         }
 401
 402         /**
 403          * Output a given item.
 404          * @param $item
 405          */
 406         function outItem( $item ) {
 407                 global $wgMimeType;
 408         ?>
 409         <entry>
 410                 <id><?php print $item->getUniqueId() ?></id>
 411                 <title><?php print $item->getTitle() ?></title>
 412                 <link rel="alternate" type="<?php print $wgMimeType ?>" href="<?php print $item->getUrl() ?>"/>
 413                 <?php if( $item->getDate() ) { ?>
 414                 <updated><?php print $this->formatTime( $item->getDate() ) ?>Z</updated>
 415                 <?php } ?>
 416
 417                 <summary type="html"><?php print $item->getDescription() ?></summary>
 418                 <?php if( $item->getAuthor() ) { ?><author><name><?php print $item->getAuthor() ?></name></author><?php }?>
 419         </entry>
 420
 421 <?php /* FIXME need to add comments
 422         <?php if( $item->getComments() ) { ?><dc:comment><?php print $item->getComments() ?></dc:comment><?php }?>
 423           */
 424         }
 425
 426         /**
 427          * Outputs the footer for Atom 1.0 feed (basicly '\</feed\>').
 428          */
 429         function outFooter() {?>
 430         </feed><?php
 431         }
 432 }