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 use MediaWiki\MediaWikiServices;
  25 use MediaWiki\Revision\RevisionRecord;
  26 use MediaWiki\Revision\SlotRecord;
  27
  28 /**
  29  * Helper functions for feeds
  30  *
  31  * @ingroup Feed
  32  */
  33 class FeedUtils {
  34
  35         /**
  36          * Check whether feeds can be used and that $type is a valid feed type
  37          *
  38          * @since 1.36 $output parameter added
  39          *
  40          * @param string $type Feed type, as requested by the user
  41          * @param OutputPage|null $output Null falls back to $wgOut
  42          * @return bool
  43          */
  44         public static function checkFeedOutput( $type, $output = null ) {
  45                 global $wgFeed, $wgFeedClasses;
  46
  47                 if ( $output === null ) {
  48                         // Todo update GoogleNewsSitemap and deprecate
  49                         global $wgOut;
  50                         $output = $wgOut;
  51                 }
  52
  53                 if ( !$wgFeed ) {
  54                         $output->addWikiMsg( 'feed-unavailable' );
  55                         return false;
  56                 }
  57
  58                 if ( !isset( $wgFeedClasses[$type] ) ) {
  59                         $output->addWikiMsg( 'feed-invalid' );
  60                         return false;
  61                 }
  62
  63                 return true;
  64         }
  65
  66         /**
  67          * Format a diff for the newsfeed
  68          *
  69          * @param stdClass $row Row from the recentchanges table, including fields as
  70          *  appropriate for CommentStore
  71          * @return string
  72          */
  73         public static function formatDiff( $row ) {
  74                 $titleObj = Title::makeTitle( $row->rc_namespace, $row->rc_title );
  75                 $timestamp = wfTimestamp( TS_MW, $row->rc_timestamp );
  76                 $actiontext = '';
  77                 if ( $row->rc_type == RC_LOG ) {
  78                         $rcRow = (array)$row; // newFromRow() only accepts arrays for RC rows
  79                         $actiontext = LogFormatter::newFromRow( $rcRow )->getActionText();
  80                 }
  81                 return self::formatDiffRow( $titleObj,
  82                         $row->rc_last_oldid, $row->rc_this_oldid,
  83                         $timestamp,
  84                         $row->rc_deleted & RevisionRecord::DELETED_COMMENT
  85                                 ? wfMessage( 'rev-deleted-comment' )->escaped()
  86                                 : CommentStore::getStore()->getComment( 'rc_comment', $row )->text,
  87                         $actiontext
  88                 );
  89         }
  90
  91         /**
  92          * Really format a diff for the newsfeed
  93          *
  94          * @param Title $title
  95          * @param int $oldid Old revision's id
  96          * @param int $newid New revision's id
  97          * @param int $timestamp New revision's timestamp
  98          * @param string $comment New revision's comment
  99          * @param string $actiontext Text of the action; in case of log event
 100          * @return string
 101          */
 102         public static function formatDiffRow( $title, $oldid, $newid, $timestamp,
 103                 $comment, $actiontext = ''
 104         ) {
 105                 global $wgFeedDiffCutoff, $wgLang;
 106
 107                 // log entries
 108                 $completeText = '<p>' . implode( ' ',
 109                         array_filter(
 110                                 [
 111                                         $actiontext,
 112                                         Linker::formatComment( $comment ) ] ) ) . "</p>\n";
 113
 114                 // NOTE: Check permissions for anonymous users, not current user.
 115                 //       No "privileged" version should end up in the cache.
 116                 //       Most feed readers will not log in anyway.
 117                 $anon = new User();
 118                 $services = MediaWikiServices::getInstance();
 119                 $permManager = $services->getPermissionManager();
 120                 $accErrors = $permManager->getPermissionErrors(
 121                         'read',
 122                         $anon,
 123                         $title
 124                 );
 125
 126                 // Can't diff special pages, unreadable pages or pages with no new revision
 127                 // to compare against: just return the text.
 128                 if ( $title->getNamespace() < 0 || $accErrors || !$newid ) {
 129                         return $completeText;
 130                 }
 131
 132                 $revLookup = $services->getRevisionLookup();
 133                 $contentHandlerFactory = $services->getContentHandlerFactory();
 134                 if ( $oldid ) {
 135                         $diffText = '';
 136                         // Don't bother generating the diff if we won't be able to show it
 137                         if ( $wgFeedDiffCutoff > 0 ) {
 138                                 $revRecord = $revLookup->getRevisionById( $oldid );
 139
 140                                 if ( !$revRecord ) {
 141                                         $diffText = false;
 142                                 } else {
 143                                         $context = clone RequestContext::getMain();
 144                                         $context->setTitle( $title );
 145
 146                                         $model = $revRecord->getSlot(
 147                                                 SlotRecord::MAIN,
 148                                                 RevisionRecord::RAW
 149                                         )->getModel();
 150                                         $contentHandler = $contentHandlerFactory->getContentHandler( $model );
 151                                         $de = $contentHandler->createDifferenceEngine( $context, $oldid, $newid );
 152                                         $diffText = $de->getDiff(
 153                                                 wfMessage( 'previousrevision' )->text(), // hack
 154                                                 wfMessage( 'revisionasof',
 155                                                         $wgLang->timeanddate( $timestamp ),
 156                                                         $wgLang->date( $timestamp ),
 157                                                         $wgLang->time( $timestamp ) )->text() );
 158                                 }
 159                         }
 160
 161                         if ( $wgFeedDiffCutoff <= 0 || ( strlen( $diffText ) > $wgFeedDiffCutoff ) ) {
 162                                 // Omit large diffs
 163                                 $diffText = self::getDiffLink( $title, $newid, $oldid );
 164                         } elseif ( $diffText === false ) {
 165                                 // Error in diff engine, probably a missing revision
 166                                 $diffText = "<p>Can't load revision $newid</p>";
 167                         } else {
 168                                 // Diff output fine, clean up any illegal UTF-8
 169                                 $diffText = UtfNormal\Validator::cleanUp( $diffText );
 170                                 $diffText = self::applyDiffStyle( $diffText );
 171                         }
 172                 } else {
 173                         $revRecord = $revLookup->getRevisionById( $newid );
 174                         if ( $wgFeedDiffCutoff <= 0 || $revRecord === null ) {
 175                                 $newContent = $contentHandlerFactory
 176                                         ->getContentHandler( $title->getContentModel() )
 177                                         ->makeEmptyContent();
 178                         } else {
 179                                 $newContent = $revRecord->getContent( SlotRecord::MAIN );
 180                         }
 181
 182                         if ( $newContent instanceof TextContent ) {
 183                                 // only textual content has a "source view".
 184                                 $text = $newContent->getText();
 185
 186                                 if ( $wgFeedDiffCutoff <= 0 || strlen( $text ) > $wgFeedDiffCutoff ) {
 187                                         $html = null;
 188                                 } else {
 189                                         $html = nl2br( htmlspecialchars( $text ) );
 190                                 }
 191                         } else {
 192                                 // XXX: we could get an HTML representation of the content via getParserOutput, but that may
 193                                 //     contain JS magic and generally may not be suitable for inclusion in a feed.
 194                                 //     Perhaps Content should have a getDescriptiveHtml method and/or a getSourceText method.
 195                                 // Compare also ApiFeedContributions::feedItemDesc
 196                                 $html = null;
 197                         }
 198
 199                         if ( $html === null ) {
 200                                 // Omit large new page diffs, T31110
 201                                 // Also use diff link for non-textual content
 202                                 $diffText = self::getDiffLink( $title, $newid );
 203                         } else {
 204                                 $diffText = '<p><b>' . wfMessage( 'newpage' )->text() . '</b></p>' .
 205                                         '<div>' . $html . '</div>';
 206                         }
 207                 }
 208                 $completeText .= $diffText;
 209
 210                 return $completeText;
 211         }
 212
 213         /**
 214          * Generates a diff link. Used when the full diff is not wanted for example
 215          * when $wgFeedDiffCutoff is 0.
 216          *
 217          * @param Title $title Title object: used to generate the diff URL
 218          * @param int $newid Newid for this diff
 219          * @param int|null $oldid Oldid for the diff. Null means it is a new article
 220          * @return string
 221          */
 222         protected static function getDiffLink( Title $title, $newid, $oldid = null ) {
 223                 $queryParameters = [ 'diff' => $newid ];
 224                 if ( $oldid != null ) {
 225                         $queryParameters['oldid'] = $oldid;
 226                 }
 227                 $diffUrl = $title->getFullURL( $queryParameters );
 228
 229                 $diffLink = Html::element( 'a', [ 'href' => $diffUrl ],
 230                         wfMessage( 'showdiff' )->inContentLanguage()->text() );
 231
 232                 return $diffLink;
 233         }
 234
 235         /**
 236          * Hacky application of diff styles for the feeds.
 237          * Might be 'cleaner' to use DOM or XSLT or something,
 238          * but *gack* it's a pain in the ass.
 239          *
 240          * @param string $text Diff's HTML output
 241          * @return string Modified HTML
 242          */
 243         public static function applyDiffStyle( $text ) {
 244                 $styles = [
 245                         'diff'             => 'background-color: #fff; color: #202122;',
 246                         'diff-otitle'      => 'background-color: #fff; color: #202122; text-align: center;',
 247                         'diff-ntitle'      => 'background-color: #fff; color: #202122; text-align: center;',
 248                         'diff-addedline'   => 'color: #202122; font-size: 88%; border-style: solid; '
 249                                 . 'border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; '
 250                                 . 'vertical-align: top; white-space: pre-wrap;',
 251                         'diff-deletedline' => 'color: #202122; font-size: 88%; border-style: solid; '
 252                                 . 'border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; '
 253                                 . 'vertical-align: top; white-space: pre-wrap;',
 254                         'diff-context'     => 'background-color: #f8f9fa; color: #202122; font-size: 88%; '
 255                                 . 'border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; '
 256                                 . 'border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;',
 257                         'diffchange'       => 'font-weight: bold; text-decoration: none;',
 258                 ];
 259
 260                 foreach ( $styles as $class => $style ) {
 261                         $text = preg_replace( '/(<\w+\b[^<>]*)\bclass=([\'"])(?:[^\'"]*\s)?' .
 262                                 preg_quote( $class ) . '(?:\s[^\'"]*)?\2(?=[^<>]*>)/',
 263                                 '$1style="' . $style . '"', $text );
 264                 }
 265
 266                 return $text;
 267         }
 268
 269 }