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