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