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