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  * https://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 string $description
  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 string $comments
  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 bool $rssIsPermalink 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          */
 194         abstract public function outHeader();
 195
 196         /**
 197          * Generate an item
 198          * @par Example:
 199          * @code
 200          * print "<item>...</item>";
 201          * @endcode
 202          * @param FeedItem $item
 203          */
 204         abstract public function outItem( $item );
 205
 206         /**
 207          * Generate Footer of the feed
 208          * @par Example:
 209          * @code
 210          * print "</feed>";
 211          * @endcode
 212          */
 213         abstract public function outFooter();
 214
 215         /**
 216          * Setup and send HTTP headers. Don't send any content;
 217          * content might end up being cached and re-sent with
 218          * these same headers later.
 219          *
 220          * This should be called from the outHeader() method,
 221          * but can also be called separately.
 222          */
 223         public function httpHeaders() {
 224                 global $wgOut, $wgVaryOnXFP;
 225
 226                 # We take over from $wgOut, excepting its cache header info
 227                 $wgOut->disable();
 228                 $mimetype = $this->contentType();
 229                 header( "Content-type: $mimetype; charset=UTF-8" );
 230                 if ( $wgVaryOnXFP ) {
 231                         $wgOut->addVaryHeader( 'X-Forwarded-Proto' );
 232                 }
 233                 $wgOut->sendCacheControl();
 234
 235         }
 236
 237         /**
 238          * Return an internet media type to be sent in the headers.
 239          *
 240          * @return string
 241          * @private
 242          */
 243         function contentType() {
 244                 global $wgRequest;
 245                 $ctype = $wgRequest->getVal( 'ctype', 'application/xml' );
 246                 $allowedctypes = array( 'application/xml', 'text/xml', 'application/rss+xml', 'application/atom+xml' );
 247                 return ( in_array( $ctype, $allowedctypes ) ? $ctype : 'application/xml' );
 248         }
 249
 250         /**
 251          * Output the initial XML headers with a stylesheet for legibility
 252          * if someone finds it in a browser.
 253          * @private
 254          */
 255         function outXmlHeader() {
 256                 global $wgStylePath, $wgStyleVersion;
 257
 258                 $this->httpHeaders();
 259                 echo '<?xml version="1.0"?>' . "\n";
 260                 echo '<?xml-stylesheet type="text/css" href="' .
 261                         htmlspecialchars( wfExpandUrl( "$wgStylePath/common/feed.css?$wgStyleVersion", PROTO_CURRENT ) ) .
 262                         '"?' . ">\n";
 263         }
 264 }
 265
 266 /**
 267  * Generate a RSS feed
 268  *
 269  * @ingroup Feed
 270  */
 271 class RSSFeed extends ChannelFeed {
 272
 273         /**
 274          * Format a date given a timestamp
 275          *
 276          * @param int $ts Timestamp
 277          * @return string Date string
 278          */
 279         function formatTime( $ts ) {
 280                 return gmdate( 'D, d M Y H:i:s \G\M\T', wfTimestamp( TS_UNIX, $ts ) );
 281         }
 282
 283         /**
 284          * Output an RSS 2.0 header
 285          */
 286         function outHeader() {
 287                 global $wgVersion;
 288
 289                 $this->outXmlHeader();
 290                 ?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
 291         <channel>
 292                 <title><?php print $this->getTitle() ?></title>
 293                 <link><?php print wfExpandUrl( $this->getUrl(), PROTO_CURRENT ) ?></link>
 294                 <description><?php print $this->getDescription() ?></description>
 295                 <language><?php print $this->getLanguage() ?></language>
 296                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 297                 <lastBuildDate><?php print $this->formatTime( wfTimestampNow() ) ?></lastBuildDate>
 298 <?php
 299         }
 300
 301         /**
 302          * Output an RSS 2.0 item
 303          * @param FeedItem $item Item to be output
 304          */
 305         function outItem( $item ) {
 306         ?>
 307                 <item>
 308                         <title><?php print $item->getTitle(); ?></title>
 309                         <link><?php print wfExpandUrl( $item->getUrl(), PROTO_CURRENT ); ?></link>
 310                         <guid<?php if ( !$item->rssIsPermalink ) { print ' isPermaLink="false"'; } ?>><?php print $item->getUniqueId(); ?></guid>
 311                         <description><?php print $item->getDescription() ?></description>
 312                         <?php if ( $item->getDate() ) { ?><pubDate><?php print $this->formatTime( $item->getDate() ); ?></pubDate><?php } ?>
 313                         <?php if ( $item->getAuthor() ) { ?><dc:creator><?php print $item->getAuthor(); ?></dc:creator><?php }?>
 314                         <?php if ( $item->getComments() ) { ?><comments><?php print wfExpandUrl( $item->getComments(), PROTO_CURRENT ); ?></comments><?php }?>
 315                 </item>
 316 <?php
 317         }
 318
 319         /**
 320          * Output an RSS 2.0 footer
 321          */
 322         function outFooter() {
 323         ?>
 324         </channel>
 325 </rss><?php
 326         }
 327 }
 328
 329 /**
 330  * Generate an Atom feed
 331  *
 332  * @ingroup Feed
 333  */
 334 class AtomFeed extends ChannelFeed {
 335         /**
 336          * @todo document
 337          * @return string
 338          */
 339         function formatTime( $ts ) {
 340                 // need to use RFC 822 time format at least for rss2.0
 341                 return gmdate( 'Y-m-d\TH:i:s', wfTimestamp( TS_UNIX, $ts ) );
 342         }
 343
 344         /**
 345          * Outputs a basic header for Atom 1.0 feeds.
 346          */
 347         function outHeader() {
 348                 global $wgVersion;
 349
 350                 $this->outXmlHeader();
 351                 ?><feed xmlns="http://www.w3.org/2005/Atom" xml:lang="<?php print $this->getLanguage() ?>">
 352                 <id><?php print $this->getFeedId() ?></id>
 353                 <title><?php print $this->getTitle() ?></title>
 354                 <link rel="self" type="application/atom+xml" href="<?php print wfExpandUrl( $this->getSelfUrl(), PROTO_CURRENT ) ?>"/>
 355                 <link rel="alternate" type="text/html" href="<?php print wfExpandUrl( $this->getUrl(), PROTO_CURRENT ) ?>"/>
 356                 <updated><?php print $this->formatTime( wfTimestampNow() ) ?>Z</updated>
 357                 <subtitle><?php print $this->getDescription() ?></subtitle>
 358                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 359
 360 <?php
 361         }
 362
 363         /**
 364          * Atom 1.0 requires a unique, opaque IRI as a unique identifier
 365          * for every feed we create. For now just use the URL, but who
 366          * can tell if that's right? If we put options on the feed, do we
 367          * have to change the id? Maybe? Maybe not.
 368          *
 369          * @return string
 370          * @private
 371          */
 372         function getFeedId() {
 373                 return $this->getSelfUrl();
 374         }
 375
 376         /**
 377          * Atom 1.0 requests a self-reference to the feed.
 378          * @return string
 379          * @private
 380          */
 381         function getSelfUrl() {
 382                 global $wgRequest;
 383                 return htmlspecialchars( $wgRequest->getFullRequestURL() );
 384         }
 385
 386         /**
 387          * Output a given item.
 388          * @param FeedItem $item
 389          */
 390         function outItem( $item ) {
 391                 global $wgMimeType;
 392         ?>
 393         <entry>
 394                 <id><?php print $item->getUniqueId(); ?></id>
 395                 <title><?php print $item->getTitle(); ?></title>
 396                 <link rel="alternate" type="<?php print $wgMimeType ?>" href="<?php print wfExpandUrl( $item->getUrl(), PROTO_CURRENT ); ?>"/>
 397                 <?php if ( $item->getDate() ) { ?>
 398                 <updated><?php print $this->formatTime( $item->getDate() ); ?>Z</updated>
 399                 <?php } ?>
 400
 401                 <summary type="html"><?php print $item->getDescription() ?></summary>
 402                 <?php if ( $item->getAuthor() ) { ?><author><name><?php print $item->getAuthor(); ?></name></author><?php }?>
 403         </entry>
 404
 405 <?php /* @todo FIXME: Need to add comments
 406         <?php if( $item->getComments() ) { ?><dc:comment><?php print $item->getComments() ?></dc:comment><?php }?>
 407           */
 408         }
 409
 410         /**
 411          * Outputs the footer for Atom 1.0 feed (basically '\</feed\>').
 412          */
 413         function outFooter() {?>
 414         </feed><?php
 415         }
 416 }