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