includes/Feed.php

   1 <?php
   2
   3 # Copyright (C) 2004 Brion Vibber <brion@pobox.com>
   4 # http://www.mediawiki.org/
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 2 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License along
  17 # with this program; if not, write to the Free Software Foundation, Inc.,
  18 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19 # http://www.gnu.org/copyleft/gpl.html
  20
  21 /**
  22  * @defgroup Feed Feed
  23  *
  24  * Basic support for outputting syndication feeds in RSS, other formats.
  25  * Contain a feed class as well as classes to build rss / atom ... feeds
  26  * Available feeds are defined in Defines.php
  27  *
  28  * @file
  29  */
  30
  31 /**
  32  * A base class for basic support for outputting syndication feeds in RSS and other formats.
  33  *
  34  * @ingroup Feed
  35  */
  36 class FeedItem {
  37         /**#@+
  38          * @var string
  39          * @private
  40          */
  41         var $Title = 'Wiki';
  42         var $Description = '';
  43         var $Url = '';
  44         var $Date = '';
  45         var $Author = '';
  46         var $UniqueId = '';
  47         var $RSSIsPermalink;
  48         /**#@-*/
  49
  50         /**
  51          * Constructor
  52          *
  53          * @param $Title String: Item's title
  54          * @param $Description String
  55          * @param $Url String: URL uniquely designating the item.
  56          * @param $Date String: Item's date
  57          * @param $Author String: Author's user name
  58          * @param $Comments String
  59          */
  60         function __construct( $Title, $Description, $Url, $Date = '', $Author = '', $Comments = '' ) {
  61                 $this->Title = $Title;
  62                 $this->Description = $Description;
  63                 $this->Url = $Url;
  64                 $this->UniqueId = $Url;
  65                 $this->RSSIsPermalink = false;
  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 = $isPermalink;
 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 $wgContLanguageCode;
 139                 return $wgContLanguageCode;
 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;
 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                 $wgOut->sendCacheControl();
 230
 231         }
 232
 233         /**
 234          * Return an internet media type to be sent in the headers.
 235          *
 236          * @return string
 237          * @private
 238          */
 239         function contentType() {
 240                 global $wgRequest;
 241                 $ctype = $wgRequest->getVal('ctype','application/xml');
 242                 $allowedctypes = array('application/xml','text/xml','application/rss+xml','application/atom+xml');
 243                 return (in_array($ctype, $allowedctypes) ? $ctype : 'application/xml');
 244         }
 245
 246         /**
 247          * Output the initial XML headers with a stylesheet for legibility
 248          * if someone finds it in a browser.
 249          * @private
 250          */
 251         function outXmlHeader() {
 252                 global $wgStylePath, $wgStyleVersion;
 253
 254                 $this->httpHeaders();
 255                 echo '<?xml version="1.0"?>' . "\n";
 256                 echo '<?xml-stylesheet type="text/css" href="' .
 257                         htmlspecialchars( wfExpandUrl( "$wgStylePath/common/feed.css?$wgStyleVersion" ) ) .
 258                         '"?' . ">\n";
 259         }
 260 }
 261
 262 /**
 263  * Generate a RSS feed
 264  *
 265  * @ingroup Feed
 266  */
 267 class RSSFeed extends ChannelFeed {
 268
 269         /**
 270          * Format a date given a timestamp
 271          *
 272          * @param $ts Integer: timestamp
 273          * @return String: date string
 274          */
 275         function formatTime( $ts ) {
 276                 return gmdate( 'D, d M Y H:i:s \G\M\T', wfTimestamp( TS_UNIX, $ts ) );
 277         }
 278
 279         /**
 280          * Ouput an RSS 2.0 header
 281          */
 282         function outHeader() {
 283                 global $wgVersion;
 284
 285                 $this->outXmlHeader();
 286                 ?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
 287         <channel>
 288                 <title><?php print $this->getTitle() ?></title>
 289                 <link><?php print $this->getUrl() ?></link>
 290                 <description><?php print $this->getDescription() ?></description>
 291                 <language><?php print $this->getLanguage() ?></language>
 292                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 293                 <lastBuildDate><?php print $this->formatTime( wfTimestampNow() ) ?></lastBuildDate>
 294 <?php
 295         }
 296
 297         /**
 298          * Output an RSS 2.0 item
 299          * @param $item FeedItem: item to be output
 300          */
 301         function outItem( $item ) {
 302         ?>
 303                 <item>
 304                         <title><?php print $item->getTitle() ?></title>
 305                         <link><?php print $item->getUrl() ?></link>
 306                         <guid<?php if( $item->RSSIsPermalink ) print ' isPermaLink="true"' ?>><?php print $item->getUniqueId() ?></guid>
 307                         <description><?php print $item->getDescription() ?></description>
 308                         <?php if( $item->getDate() ) { ?><pubDate><?php print $this->formatTime( $item->getDate() ) ?></pubDate><?php } ?>
 309                         <?php if( $item->getAuthor() ) { ?><dc:creator><?php print $item->getAuthor() ?></dc:creator><?php }?>
 310                         <?php if( $item->getComments() ) { ?><comments><?php print $item->getComments() ?></comments><?php }?>
 311                 </item>
 312 <?php
 313         }
 314
 315         /**
 316          * Ouput an RSS 2.0 footer
 317          */
 318         function outFooter() {
 319         ?>
 320         </channel>
 321 </rss><?php
 322         }
 323 }
 324
 325 /**
 326  * Generate an Atom feed
 327  *
 328  * @ingroup Feed
 329  */
 330 class AtomFeed extends ChannelFeed {
 331         /**
 332          * @todo document
 333          */
 334         function formatTime( $ts ) {
 335                 // need to use RFC 822 time format at least for rss2.0
 336                 return gmdate( 'Y-m-d\TH:i:s', wfTimestamp( TS_UNIX, $ts ) );
 337         }
 338
 339         /**
 340          * Outputs a basic header for Atom 1.0 feeds.
 341          */
 342         function outHeader() {
 343                 global $wgVersion;
 344
 345                 $this->outXmlHeader();
 346                 ?><feed xmlns="http://www.w3.org/2005/Atom" xml:lang="<?php print $this->getLanguage() ?>">
 347                 <id><?php print $this->getFeedId() ?></id>
 348                 <title><?php print $this->getTitle() ?></title>
 349                 <link rel="self" type="application/atom+xml" href="<?php print $this->getSelfUrl() ?>"/>
 350                 <link rel="alternate" type="text/html" href="<?php print $this->getUrl() ?>"/>
 351                 <updated><?php print $this->formatTime( wfTimestampNow() ) ?>Z</updated>
 352                 <subtitle><?php print $this->getDescription() ?></subtitle>
 353                 <generator>MediaWiki <?php print $wgVersion ?></generator>
 354
 355 <?php
 356         }
 357
 358         /**
 359          * Atom 1.0 requires a unique, opaque IRI as a unique indentifier
 360          * for every feed we create. For now just use the URL, but who
 361          * can tell if that's right? If we put options on the feed, do we
 362          * have to change the id? Maybe? Maybe not.
 363          *
 364          * @return string
 365          * @private
 366          */
 367         function getFeedId() {
 368                 return $this->getSelfUrl();
 369         }
 370
 371         /**
 372          * Atom 1.0 requests a self-reference to the feed.
 373          * @return string
 374          * @private
 375          */
 376         function getSelfUrl() {
 377                 global $wgRequest;
 378                 return htmlspecialchars( $wgRequest->getFullRequestURL() );
 379         }
 380
 381         /**
 382          * Output a given item.
 383          * @param $item
 384          */
 385         function outItem( $item ) {
 386                 global $wgMimeType;
 387         ?>
 388         <entry>
 389                 <id><?php print $item->getUniqueId() ?></id>
 390                 <title><?php print $item->getTitle() ?></title>
 391                 <link rel="alternate" type="<?php print $wgMimeType ?>" href="<?php print $item->getUrl() ?>"/>
 392                 <?php if( $item->getDate() ) { ?>
 393                 <updated><?php print $this->formatTime( $item->getDate() ) ?>Z</updated>
 394                 <?php } ?>
 395
 396                 <summary type="html"><?php print $item->getDescription() ?></summary>
 397                 <?php if( $item->getAuthor() ) { ?><author><name><?php print $item->getAuthor() ?></name></author><?php }?>
 398         </entry>
 399
 400 <?php /* FIXME need to add comments
 401         <?php if( $item->getComments() ) { ?><dc:comment><?php print $item->getComments() ?></dc:comment><?php }?>
 402       */
 403         }
 404
 405         /**
 406          * Outputs the footer for Atom 1.0 feed (basicly '\</feed\>').
 407          */
 408         function outFooter() {?>
 409         </feed><?php
 410         }
 411 }