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          * Get the last touched timestamp
  84          *
  85          * @return String last-touched timestamp
  86          */
  87         public function getLastMod() {
  88                 return $this->Title->getTouched();
  89         }
  90
  91         /**
  92          * Encode $string so that it can be safely embedded in a XML document
  93          *
  94          * @param $string String: string to encode
  95          * @return String
  96          */
  97         public function xmlEncode( $string ) {
  98                 $string = str_replace( "\r\n", "\n", $string );
  99                 $string = preg_replace( '/[\x00-\x08\x0b\x0c\x0e-\x1f]/', '', $string );
 100                 return htmlspecialchars( $string );
 101         }
 102
 103         /**
 104          * Get the unique id of this item
 105          *
 106          * @return String
 107          */
 108         public function getUniqueId() {
 109                 if ( $this->UniqueId ) {
 110                         return $this->xmlEncode( $this->UniqueId );
 111                 }
 112         }
 113
 114         /**
 115          * set the unique id of an item
 116          *
 117          * @param $uniqueId String: unique id for the item
 118          * @param $RSSisPermalink Boolean: set to true if the guid (unique id) is a permalink (RSS feeds only)
 119          */
 120         public function setUniqueId($uniqueId, $RSSisPermalink = false) {
 121                 $this->UniqueId = $uniqueId;
 122                 $this->RSSIsPermalink = $RSSisPermalink;
 123         }
 124
 125         /**
 126          * Get the title of this item; already xml-encoded
 127          *
 128          * @return String
 129          */
 130         public function getTitle() {
 131                 return $this->xmlEncode( $this->Title );
 132         }
 133
 134         /**
 135          * Get the DB prefixed title
 136          *
 137          * @return String the prefixed title, with underscores and
 138          *  any interwiki and namespace prefixes
 139          */
 140         public function getDBPrefixedTitle() {
 141                 return $this->Title->getPrefixedDBKey();
 142         }
 143
 144         /**
 145          * Get the DB prefixed title
 146          *
 147          * @return String the prefixed title, with underscores and
 148          *  any interwiki and namespace prefixes
 149          */
 150         public function getDBPrefixedTitle() {
 151                 return $this->Title->getPrefixedDBKey(),
 152         }
 153
 154         /**
 155          * Get the URL of this item; already xml-encoded
 156          *
 157          * @return String
 158          */
 159         public function getUrl() {
 160                 return $this->xmlEncode( $this->Url );
 161         }
 162
 163         /**
 164          * Get the description of this item; already xml-encoded
 165          *
 166          * @return String
 167          */
 168         public function getDescription() {
 169                 return $this->xmlEncode( $this->Description );
 170         }
 171
 172         /**
 173          * Get the language of this item
 174          *
 175          * @return String
 176          */
 177         public function getLanguage() {
 178                 global $wgLanguageCode;
 179                 return $wgLanguageCode;
 180         }
 181
 182         /**
 183          * Get the title of this item
 184          *
 185          * @return String
 186          */
 187         public function getDate() {
 188                 return $this->Date;
 189         }
 190
 191         /**
 192          * Get the author of this item; already xml-encoded
 193          *
 194          * @return String
 195          */
 196         public function getAuthor() {
 197                 return $this->xmlEncode( $this->Author );
 198         }
 199
 200         /**
 201          * Get the comment of this item; already xml-encoded
 202          *
 203          * @return String
 204          */
 205         public function getComments() {
 206                 return $this->xmlEncode( $this->Comments );
 207         }
 208
 209         /**
 210          * Quickie hack... strip out wikilinks to more legible form from the comment.
 211          *
 212          * @param $text String: wikitext
 213          * @return String
 214          */
 215         public static function stripComment( $text ) {
 216                 return preg_replace( '/\[\[([^]]*\|)?([^]]+)\]\]/', '\2', $text );
 217         }
 218         /**#@-*/
 219 }
 220
 221 /**
 222  * @todo document (needs one-sentence top-level class description).
 223  * @ingroup Feed
 224  */
 225 class ChannelFeed extends FeedItem {
 226         /**#@+
 227          * Abstract function, override!
 228          * @abstract
 229          */
 230
 231         /**
 232          * Generate Header of the feed
 233          */
 234         function outHeader() {
 235                 # print "<feed>";
 236         }
 237
 238         /**
 239          * Generate an item
 240          * @param $item
 241          */
 242         function outItem( $item ) {
 243                 # print "<item>...</item>";
 244         }
 245
 246         /**
 247          * Generate Footer of the feed
 248          */
 249         function outFooter() {
 250                 # print "</feed>";
 251         }
 252         /**#@-*/
 253
 254         /**
 255          * Setup and send HTTP headers. Don't send any content;
 256          * content might end up being cached and re-sent with
 257          * these same headers later.
 258          *
 259          * This should be called from the outHeader() method,
 260          * but can also be called separately.
 261          */
 262         public function httpHeaders() {
 263                 global $wgOut;
 264
 265                 # We take over from $wgOut, excepting its cache header info
 266                 $wgOut->disable();
 267                 $mimetype = $this->contentType();
 268                 header( "Content-type: $mimetype; charset=UTF-8" );
 269                 $wgOut->sendCacheControl();
 270
 271         }
 272
 273         /**
 274          * Return an internet media type to be sent in the headers.
 275          *
 276          * @return string
 277          * @private
 278          */
 279         function contentType() {
 280                 global $wgRequest;
 281                 $ctype = $wgRequest->getVal('ctype','application/xml');
 282                 $allowedctypes = array('application/xml','text/xml','application/rss+xml','application/atom+xml');
 283                 return (in_array($ctype, $allowedctypes) ? $ctype : 'application/xml');
 284         }
 285
 286         /**
 287          * Output the initial XML headers with a stylesheet for legibility
 288          * if someone finds it in a browser.
 289          * @private
 290          */
 291         function outXmlHeader() {
 292                 global $wgStylePath, $wgStyleVersion;
 293
 294                 $this->httpHeaders();
 295                 echo '<?xml version="1.0"?>' . "\n";
 296                 echo '<?xml-stylesheet type="text/css" href="' .
 297                         htmlspecialchars( wfExpandUrl( "$wgStylePath/common/feed.css?$wgStyleVersion" ) ) .
 298                         '"?' . ">\n";
 299         }
 300 }
 301
 302 /**
 303  * Generate a RSS feed
 304  *
 305  * @ingroup Feed
 306  */
 307 class RSSFeed extends ChannelFeed {
 308
 309         /**
 310          * Format a date given a timestamp
 311          *
 312          * @param $ts Integer: timestamp
 313          * @return String: date string
 314          */
 315         function formatTime( $ts ) {
 316                 return gmdate( 'D, d M Y H:i:s \G\M\T', wfTimestamp( TS_UNIX, $ts ) );
 317         }
 318
 319         /**
 320          * Ouput an RSS 2.0 header
 321          */
 322         function outHeader() {
 323                 global $wgVersion;
 324
 325                 $this->outXmlHeader();
 326                 ?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
 327         <channel>
 328                 <title><?php print $this->getTitle() ?></title>
 329                 <link><?php print $this->getUrl() ?></link>
 330                 <description><?php print $this->getDescription() ?></description>
 331                 <language><?php print $this->getLanguage() ?></language>
 332                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 333                 <lastBuildDate><?php print $this->formatTime( wfTimestampNow() ) ?></lastBuildDate>
 334 <?php
 335         }
 336
 337         /**
 338          * Output an RSS 2.0 item
 339          * @param $item FeedItem: item to be output
 340          */
 341         function outItem( $item ) {
 342         ?>
 343                 <item>
 344                         <title><?php print $item->getTitle() ?></title>
 345                         <link><?php print $item->getUrl() ?></link>
 346                         <guid<?php if( !$item->RSSIsPermalink ) print ' isPermaLink="false"' ?>><?php print $item->getUniqueId() ?></guid>
 347                         <description><?php print $item->getDescription() ?></description>
 348                         <?php if( $item->getDate() ) { ?><pubDate><?php print $this->formatTime( $item->getDate() ) ?></pubDate><?php } ?>
 349                         <?php if( $item->getAuthor() ) { ?><dc:creator><?php print $item->getAuthor() ?></dc:creator><?php }?>
 350                         <?php if( $item->getComments() ) { ?><comments><?php print $item->getComments() ?></comments><?php }?>
 351                 </item>
 352 <?php
 353         }
 354
 355         /**
 356          * Ouput an RSS 2.0 footer
 357          */
 358         function outFooter() {
 359         ?>
 360         </channel>
 361 </rss><?php
 362         }
 363 }
 364
 365 /**
 366  * Generate an Atom feed
 367  *
 368  * @ingroup Feed
 369  */
 370 class AtomFeed extends ChannelFeed {
 371         /**
 372          * @todo document
 373          */
 374         function formatTime( $ts ) {
 375                 // need to use RFC 822 time format at least for rss2.0
 376                 return gmdate( 'Y-m-d\TH:i:s', wfTimestamp( TS_UNIX, $ts ) );
 377         }
 378
 379         /**
 380          * Outputs a basic header for Atom 1.0 feeds.
 381          */
 382         function outHeader() {
 383                 global $wgVersion;
 384
 385                 $this->outXmlHeader();
 386                 ?><feed xmlns="http://www.w3.org/2005/Atom" xml:lang="<?php print $this->getLanguage() ?>">
 387                 <id><?php print $this->getFeedId() ?></id>
 388                 <title><?php print $this->getTitle() ?></title>
 389                 <link rel="self" type="application/atom+xml" href="<?php print $this->getSelfUrl() ?>"/>
 390                 <link rel="alternate" type="text/html" href="<?php print $this->getUrl() ?>"/>
 391                 <updated><?php print $this->formatTime( wfTimestampNow() ) ?>Z</updated>
 392                 <subtitle><?php print $this->getDescription() ?></subtitle>
 393                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 394
 395 <?php
 396         }
 397
 398         /**
 399          * Atom 1.0 requires a unique, opaque IRI as a unique indentifier
 400          * for every feed we create. For now just use the URL, but who
 401          * can tell if that's right? If we put options on the feed, do we
 402          * have to change the id? Maybe? Maybe not.
 403          *
 404          * @return string
 405          * @private
 406          */
 407         function getFeedId() {
 408                 return $this->getSelfUrl();
 409         }
 410
 411         /**
 412          * Atom 1.0 requests a self-reference to the feed.
 413          * @return string
 414          * @private
 415          */
 416         function getSelfUrl() {
 417                 global $wgRequest;
 418                 return htmlspecialchars( $wgRequest->getFullRequestURL() );
 419         }
 420
 421         /**
 422          * Output a given item.
 423          * @param $item
 424          */
 425         function outItem( $item ) {
 426                 global $wgMimeType;
 427         ?>
 428         <entry>
 429                 <id><?php print $item->getUniqueId() ?></id>
 430                 <title><?php print $item->getTitle() ?></title>
 431                 <link rel="alternate" type="<?php print $wgMimeType ?>" href="<?php print $item->getUrl() ?>"/>
 432                 <?php if( $item->getDate() ) { ?>
 433                 <updated><?php print $this->formatTime( $item->getDate() ) ?>Z</updated>
 434                 <?php } ?>
 435
 436                 <summary type="html"><?php print $item->getDescription() ?></summary>
 437                 <?php if( $item->getAuthor() ) { ?><author><name><?php print $item->getAuthor() ?></name></author><?php }?>
 438         </entry>
 439
 440 <?php /* FIXME need to add comments
 441         <?php if( $item->getComments() ) { ?><dc:comment><?php print $item->getComments() ?></dc:comment><?php }?>
 442           */
 443         }
 444
 445         /**
 446          * Outputs the footer for Atom 1.0 feed (basicly '\</feed\>').
 447          */
 448         function outFooter() {?>
 449         </feed><?php
 450         }
 451 }