includes/FeedUtils.php

   1 <?php
   2 /**
   3  * Helper functions for feeds.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Feed
  22  */
  23
  24 /**
  25  * Helper functions for feeds
  26  *
  27  * @ingroup Feed
  28  */
  29 class FeedUtils {
  30
  31         /**
  32          * Check whether feed's cache should be cleared; for changes feeds
  33          * If the feed should be purged; $timekey and $key will be removed from
  34          * $messageMemc
  35          *
  36          * @param string $timekey Cache key of the timestamp of the last item
  37          * @param string $key Cache key of feed's content
  38          */
  39         public static function checkPurge( $timekey, $key ) {
  40                 global $wgRequest, $wgUser, $messageMemc;
  41                 $purge = $wgRequest->getVal( 'action' ) === 'purge';
  42                 if ( $purge && $wgUser->isAllowed( 'purge' ) ) {
  43                         $messageMemc->delete( $timekey );
  44                         $messageMemc->delete( $key );
  45                 }
  46         }
  47
  48         /**
  49          * Check whether feeds can be used and that $type is a valid feed type
  50          *
  51          * @param string $type Feed type, as requested by the user
  52          * @return bool
  53          */
  54         public static function checkFeedOutput( $type ) {
  55                 global $wgOut, $wgFeed, $wgFeedClasses;
  56
  57                 if ( !$wgFeed ) {
  58                         $wgOut->addWikiMsg( 'feed-unavailable' );
  59                         return false;
  60                 }
  61
  62                 if ( !isset( $wgFeedClasses[$type] ) ) {
  63                         $wgOut->addWikiMsg( 'feed-invalid' );
  64                         return false;
  65                 }
  66
  67                 return true;
  68         }
  69
  70         /**
  71          * Format a diff for the newsfeed
  72          *
  73          * @param object $row Row from the recentchanges table
  74          * @return string
  75          */
  76         public static function formatDiff( $row ) {
  77                 $titleObj = Title::makeTitle( $row->rc_namespace, $row->rc_title );
  78                 $timestamp = wfTimestamp( TS_MW, $row->rc_timestamp );
  79                 $actiontext = '';
  80                 if ( $row->rc_type == RC_LOG ) {
  81                         $rcRow = (array)$row; // newFromRow() only accepts arrays for RC rows
  82                         $actiontext = LogFormatter::newFromRow( $rcRow )->getActionText();
  83                 }
  84                 return self::formatDiffRow( $titleObj,
  85                         $row->rc_last_oldid, $row->rc_this_oldid,
  86                         $timestamp,
  87                         $row->rc_deleted & Revision::DELETED_COMMENT
  88                                 ? wfMessage( 'rev-deleted-comment' )->escaped()
  89                                 : $row->rc_comment,
  90                         $actiontext
  91                 );
  92         }
  93
  94         /**
  95          * Really format a diff for the newsfeed
  96          *
  97          * @param Title $title Title object
  98          * @param int $oldid Old revision's id
  99          * @param int $newid New revision's id
 100          * @param int $timestamp New revision's timestamp
 101          * @param string $comment New revision's comment
 102          * @param string $actiontext Text of the action; in case of log event
 103          * @return string
 104          */
 105         public static function formatDiffRow( $title, $oldid, $newid, $timestamp,
 106                 $comment, $actiontext = ''
 107         ) {
 108                 global $wgFeedDiffCutoff, $wgLang;
 109
 110                 // log entries
 111                 $completeText = '<p>' . implode( ' ',
 112                         array_filter(
 113                                 array(
 114                                         $actiontext,
 115                                         Linker::formatComment( $comment ) ) ) ) . "</p>\n";
 116
 117                 // NOTE: Check permissions for anonymous users, not current user.
 118                 //       No "privileged" version should end up in the cache.
 119                 //       Most feed readers will not log in anyway.
 120                 $anon = new User();
 121                 $accErrors = $title->getUserPermissionsErrors( 'read', $anon, true );
 122
 123                 // Can't diff special pages, unreadable pages or pages with no new revision
 124                 // to compare against: just return the text.
 125                 if ( $title->getNamespace() < 0 || $accErrors || !$newid ) {
 126                         return $completeText;
 127                 }
 128
 129                 if ( $oldid ) {
 130
 131                         #$diffText = $de->getDiff( wfMessage( 'revisionasof',
 132                         #       $wgLang->timeanddate( $timestamp ),
 133                         #       $wgLang->date( $timestamp ),
 134                         #       $wgLang->time( $timestamp ) )->text(),
 135                         #       wfMessage( 'currentrev' )->text() );
 136
 137                         $diffText = '';
 138                         // Don't bother generating the diff if we won't be able to show it
 139                         if ( $wgFeedDiffCutoff > 0 ) {
 140                                 $rev = Revision::newFromId( $oldid );
 141
 142                                 if ( !$rev ) {
 143                                         $diffText = false;
 144                                 } else {
 145                                         $context = clone RequestContext::getMain();
 146                                         $context->setTitle( $title );
 147
 148                                         $contentHandler = $rev->getContentHandler();
 149                                         $de = $contentHandler->createDifferenceEngine( $context, $oldid, $newid );
 150                                         $diffText = $de->getDiff(
 151                                                 wfMessage( 'previousrevision' )->text(), // hack
 152                                                 wfMessage( 'revisionasof',
 153                                                         $wgLang->timeanddate( $timestamp ),
 154                                                         $wgLang->date( $timestamp ),
 155                                                         $wgLang->time( $timestamp ) )->text() );
 156                                 }
 157                         }
 158
 159                         if ( $wgFeedDiffCutoff <= 0 || ( strlen( $diffText ) > $wgFeedDiffCutoff ) ) {
 160                                 // Omit large diffs
 161                                 $diffText = self::getDiffLink( $title, $newid, $oldid );
 162                         } elseif ( $diffText === false ) {
 163                                 // Error in diff engine, probably a missing revision
 164                                 $diffText = "<p>Can't load revision $newid</p>";
 165                         } else {
 166                                 // Diff output fine, clean up any illegal UTF-8
 167                                 $diffText = UtfNormal::cleanUp( $diffText );
 168                                 $diffText = self::applyDiffStyle( $diffText );
 169                         }
 170                 } else {
 171                         $rev = Revision::newFromId( $newid );
 172                         if ( $wgFeedDiffCutoff <= 0 || is_null( $rev ) ) {
 173                                 $newContent = ContentHandler::getForTitle( $title )->makeEmptyContent();
 174                         } else {
 175                                 $newContent = $rev->getContent();
 176                         }
 177
 178                         if ( $newContent instanceof TextContent ) {
 179                                 // only textual content has a "source view".
 180                                 $text = $newContent->getNativeData();
 181
 182                                 if ( $wgFeedDiffCutoff <= 0 || strlen( $text ) > $wgFeedDiffCutoff ) {
 183                                         $html = null;
 184                                 } else {
 185                                         $html = nl2br( htmlspecialchars( $text ) );
 186                                 }
 187                         } else {
 188                                 //XXX: we could get an HTML representation of the content via getParserOutput, but that may
 189                                 //     contain JS magic and generally may not be suitable for inclusion in a feed.
 190                                 //     Perhaps Content should have a getDescriptiveHtml method and/or a getSourceText method.
 191                                 //Compare also ApiFeedContributions::feedItemDesc
 192                                 $html = null;
 193                         }
 194
 195                         if ( $html === null ) {
 196
 197                                 // Omit large new page diffs, bug 29110
 198                                 // Also use diff link for non-textual content
 199                                 $diffText = self::getDiffLink( $title, $newid );
 200                         } else {
 201                                 $diffText = '<p><b>' . wfMessage( 'newpage' )->text() . '</b></p>' .
 202                                         '<div>' . $html . '</div>';
 203                         }
 204                 }
 205                 $completeText .= $diffText;
 206
 207                 return $completeText;
 208         }
 209
 210         /**
 211          * Generates a diff link. Used when the full diff is not wanted for example
 212          * when $wgFeedDiffCutoff is 0.
 213          *
 214          * @param Title $title Title object: used to generate the diff URL
 215          * @param int $newid Newid for this diff
 216          * @param int|null $oldid Oldid for the diff. Null means it is a new article
 217          * @return string
 218          */
 219         protected static function getDiffLink( Title $title, $newid, $oldid = null ) {
 220                 $queryParameters = array( 'diff' => $newid );
 221                 if ( $oldid != null ) {
 222                         $queryParameters['oldid'] = $oldid;
 223                 }
 224                 $diffUrl = $title->getFullURL( $queryParameters );
 225
 226                 $diffLink = Html::element( 'a', array( 'href' => $diffUrl ),
 227                         wfMessage( 'showdiff' )->inContentLanguage()->text() );
 228
 229                 return $diffLink;
 230         }
 231
 232         /**
 233          * Hacky application of diff styles for the feeds.
 234          * Might be 'cleaner' to use DOM or XSLT or something,
 235          * but *gack* it's a pain in the ass.
 236          *
 237          * @param string $text Diff's HTML output
 238          * @return string Modified HTML
 239          */
 240         public static function applyDiffStyle( $text ) {
 241                 $styles = array(
 242                         'diff'             => 'background-color: white; color:black;',
 243                         'diff-otitle'      => 'background-color: white; color:black; text-align: center;',
 244                         'diff-ntitle'      => 'background-color: white; color:black; text-align: center;',
 245                         'diff-addedline'   => 'color:black; font-size: 88%; border-style: solid; '
 246                                 . 'border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; '
 247                                 . 'vertical-align: top; white-space: pre-wrap;',
 248                         'diff-deletedline' => 'color:black; font-size: 88%; border-style: solid; '
 249                                 . 'border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; '
 250                                 . 'vertical-align: top; white-space: pre-wrap;',
 251                         'diff-context'     => 'background-color: #f9f9f9; color: #333333; font-size: 88%; '
 252                                 . 'border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; '
 253                                 . 'border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;',
 254                         'diffchange'       => 'font-weight: bold; text-decoration: none;',
 255                 );
 256
 257                 foreach ( $styles as $class => $style ) {
 258                         $text = preg_replace( "/(<[^>]+)class=(['\"])$class\\2([^>]*>)/",
 259                                 "\\1style=\"$style\"\\3", $text );
 260                 }
 261
 262                 return $text;
 263         }
 264
 265 }