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 $timekey String: cache key of the timestamp of the last item
  37          * @param $key String: 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 $type String: feed type, as requested by the user
  52          * @return Boolean
  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 $row Object: 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                                 ? wfMsgHtml('rev-deleted-comment')
  89                                 : $row->rc_comment,
  90                         $actiontext
  91                 );
  92         }
  93
  94         /**
  95          * Really format a diff for the newsfeed
  96          *
  97          * @param $title Title object
  98          * @param $oldid Integer: old revision's id
  99          * @param $newid Integer: new revision's id
 100          * @param $timestamp Integer: new revision's timestamp
 101          * @param $comment String: new revision's comment
 102          * @param $actiontext String: text of the action; in case of log event
 103          * @return String
 104          */
 105         public static function formatDiffRow( $title, $oldid, $newid, $timestamp, $comment, $actiontext='' ) {
 106                 global $wgFeedDiffCutoff, $wgLang;
 107                 wfProfileIn( __METHOD__ );
 108
 109                 # log enties
 110                 $completeText = '<p>' . implode( ' ',
 111                         array_filter(
 112                                 array(
 113                                         $actiontext,
 114                                         Linker::formatComment( $comment ) ) ) ) . "</p>\n";
 115
 116                 // NOTE: Check permissions for anonymous users, not current user.
 117                 //       No "privileged" version should end up in the cache.
 118                 //       Most feed readers will not log in anway.
 119                 $anon = new User();
 120                 $accErrors = $title->getUserPermissionsErrors( 'read', $anon, true );
 121
 122                 // Can't diff special pages, unreadable pages or pages with no new revision
 123                 // to compare against: just return the text.
 124                 if( $title->getNamespace() < 0 || $accErrors || !$newid ) {
 125                         wfProfileOut( __METHOD__ );
 126                         return $completeText;
 127                 }
 128
 129                 if( $oldid ) {
 130                         wfProfileIn( __METHOD__."-dodiff" );
 131
 132                         #$diffText = $de->getDiff( wfMsg( 'revisionasof',
 133                         #       $wgLang->timeanddate( $timestamp ),
 134                         #       $wgLang->date( $timestamp ),
 135                         #       $wgLang->time( $timestamp ) ),
 136                         #       wfMsg( 'currentrev' ) );
 137
 138                         $diffText = '';
 139                         // Don't bother generating the diff if we won't be able to show it
 140                         if ( $wgFeedDiffCutoff > 0 ) {
 141                                 $de = new DifferenceEngine( $title, $oldid, $newid );
 142                                 $diffText = $de->getDiff(
 143                                         wfMsg( 'previousrevision' ), // hack
 144                                         wfMsg( 'revisionasof',
 145                                         $wgLang->timeanddate( $timestamp ),
 146                                         $wgLang->date( $timestamp ),
 147                                         $wgLang->time( $timestamp ) ) );
 148                         }
 149
 150                         if ( $wgFeedDiffCutoff <= 0 || ( strlen( $diffText ) > $wgFeedDiffCutoff ) ) {
 151                                 // Omit large diffs
 152                                 $diffText = self::getDiffLink( $title, $newid, $oldid );
 153                         } elseif ( $diffText === false ) {
 154                                 // Error in diff engine, probably a missing revision
 155                                 $diffText = "<p>Can't load revision $newid</p>";
 156                         } else {
 157                                 // Diff output fine, clean up any illegal UTF-8
 158                                 $diffText = UtfNormal::cleanUp( $diffText );
 159                                 $diffText = self::applyDiffStyle( $diffText );
 160                         }
 161                         wfProfileOut( __METHOD__."-dodiff" );
 162                 } else {
 163                         $rev = Revision::newFromId( $newid );
 164                         if( $wgFeedDiffCutoff <= 0 || is_null( $rev ) ) {
 165                                 $newtext = '';
 166                         } else {
 167                                 $newtext = $rev->getText();
 168                         }
 169                         if ( $wgFeedDiffCutoff <= 0 || strlen( $newtext ) > $wgFeedDiffCutoff ) {
 170                                 // Omit large new page diffs, bug 29110
 171                                 $diffText = self::getDiffLink( $title, $newid );
 172                         } else {
 173                                 $diffText = '<p><b>' . wfMsg( 'newpage' ) . '</b></p>' .
 174                                         '<div>' . nl2br( htmlspecialchars( $newtext ) ) . '</div>';
 175                         }
 176                 }
 177                 $completeText .= $diffText;
 178
 179                 wfProfileOut( __METHOD__ );
 180                 return $completeText;
 181         }
 182
 183         /**
 184          * Generates a diff link. Used when the full diff is not wanted for example
 185          * when $wgFeedDiffCutoff is 0.
 186          *
 187          * @param $title Title object: used to generate the diff URL
 188          * @param $newid Integer newid for this diff
 189          * @param $oldid Integer|null oldid for the diff. Null means it is a new article
 190          * @return string
 191          */
 192         protected static function getDiffLink( Title $title, $newid, $oldid = null ) {
 193                 $queryParameters = ($oldid == null)
 194                         ? "diff={$newid}"
 195                         : "diff={$newid}&oldid={$oldid}" ;
 196                 $diffUrl = $title->getFullUrl( $queryParameters );
 197
 198                 $diffLink = Html::element( 'a', array( 'href' => $diffUrl ),
 199                         wfMsgForContent( 'showdiff' ) );
 200
 201                 return $diffLink;
 202         }
 203
 204         /**
 205          * Hacky application of diff styles for the feeds.
 206          * Might be 'cleaner' to use DOM or XSLT or something,
 207          * but *gack* it's a pain in the ass.
 208          *
 209          * @param $text String: diff's HTML output
 210          * @return String: modified HTML
 211          */
 212         public static function applyDiffStyle( $text ) {
 213                 $styles = array(
 214                         'diff'             => 'background-color: white; color:black;',
 215                         'diff-otitle'      => 'background-color: white; color:black;',
 216                         'diff-ntitle'      => 'background-color: white; color:black;',
 217                         'diff-addedline'   => 'background: #cfc; color:black; font-size: smaller;',
 218                         'diff-deletedline' => 'background: #ffa; color:black; font-size: smaller;',
 219                         'diff-context'     => 'background: #eee; color:black; font-size: smaller;',
 220                         'diffchange'       => 'color: red; font-weight: bold; text-decoration: none;',
 221                 );
 222
 223                 foreach( $styles as $class => $style ) {
 224                         $text = preg_replace( "/(<[^>]+)class=(['\"])$class\\2([^>]*>)/",
 225                                 "\\1style=\"$style\"\\3", $text );
 226                 }
 227
 228                 return $text;
 229         }
 230
 231 }