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 feeds can be used and that $type is a valid feed type
  33          *
  34          * @param string $type Feed type, as requested by the user
  35          * @return bool
  36          */
  37         public static function checkFeedOutput( $type ) {
  38                 global $wgOut, $wgFeed, $wgFeedClasses;
  39
  40                 if ( !$wgFeed ) {
  41                         $wgOut->addWikiMsg( 'feed-unavailable' );
  42                         return false;
  43                 }
  44
  45                 if ( !isset( $wgFeedClasses[$type] ) ) {
  46                         $wgOut->addWikiMsg( 'feed-invalid' );
  47                         return false;
  48                 }
  49
  50                 return true;
  51         }
  52
  53         /**
  54          * Format a diff for the newsfeed
  55          *
  56          * @param object $row Row from the recentchanges table, including fields as
  57          *  appropriate for CommentStore
  58          * @return string
  59          */
  60         public static function formatDiff( $row ) {
  61                 $titleObj = Title::makeTitle( $row->rc_namespace, $row->rc_title );
  62                 $timestamp = wfTimestamp( TS_MW, $row->rc_timestamp );
  63                 $actiontext = '';
  64                 if ( $row->rc_type == RC_LOG ) {
  65                         $rcRow = (array)$row; // newFromRow() only accepts arrays for RC rows
  66                         $actiontext = LogFormatter::newFromRow( $rcRow )->getActionText();
  67                 }
  68                 return self::formatDiffRow( $titleObj,
  69                         $row->rc_last_oldid, $row->rc_this_oldid,
  70                         $timestamp,
  71                         $row->rc_deleted & Revision::DELETED_COMMENT
  72                                 ? wfMessage( 'rev-deleted-comment' )->escaped()
  73                                 : CommentStore::getStore()->getComment( 'rc_comment', $row )->text,
  74                         $actiontext
  75                 );
  76         }
  77
  78         /**
  79          * Really format a diff for the newsfeed
  80          *
  81          * @param Title $title
  82          * @param int $oldid Old revision's id
  83          * @param int $newid New revision's id
  84          * @param int $timestamp New revision's timestamp
  85          * @param string $comment New revision's comment
  86          * @param string $actiontext Text of the action; in case of log event
  87          * @return string
  88          */
  89         public static function formatDiffRow( $title, $oldid, $newid, $timestamp,
  90                 $comment, $actiontext = ''
  91         ) {
  92                 global $wgFeedDiffCutoff, $wgLang;
  93
  94                 // log entries
  95                 $completeText = '<p>' . implode( ' ',
  96                         array_filter(
  97                                 [
  98                                         $actiontext,
  99                                         Linker::formatComment( $comment ) ] ) ) . "</p>\n";
 100
 101                 // NOTE: Check permissions for anonymous users, not current user.
 102                 //       No "privileged" version should end up in the cache.
 103                 //       Most feed readers will not log in anyway.
 104                 $anon = new User();
 105                 $accErrors = $title->getUserPermissionsErrors( 'read', $anon, true );
 106
 107                 // Can't diff special pages, unreadable pages or pages with no new revision
 108                 // to compare against: just return the text.
 109                 if ( $title->getNamespace() < 0 || $accErrors || !$newid ) {
 110                         return $completeText;
 111                 }
 112
 113                 if ( $oldid ) {
 114                         $diffText = '';
 115                         // Don't bother generating the diff if we won't be able to show it
 116                         if ( $wgFeedDiffCutoff > 0 ) {
 117                                 $rev = Revision::newFromId( $oldid );
 118
 119                                 if ( !$rev ) {
 120                                         $diffText = false;
 121                                 } else {
 122                                         $context = clone RequestContext::getMain();
 123                                         $context->setTitle( $title );
 124
 125                                         $contentHandler = $rev->getContentHandler();
 126                                         $de = $contentHandler->createDifferenceEngine( $context, $oldid, $newid );
 127                                         $diffText = $de->getDiff(
 128                                                 wfMessage( 'previousrevision' )->text(), // hack
 129                                                 wfMessage( 'revisionasof',
 130                                                         $wgLang->timeanddate( $timestamp ),
 131                                                         $wgLang->date( $timestamp ),
 132                                                         $wgLang->time( $timestamp ) )->text() );
 133                                 }
 134                         }
 135
 136                         if ( $wgFeedDiffCutoff <= 0 || ( strlen( $diffText ) > $wgFeedDiffCutoff ) ) {
 137                                 // Omit large diffs
 138                                 $diffText = self::getDiffLink( $title, $newid, $oldid );
 139                         } elseif ( $diffText === false ) {
 140                                 // Error in diff engine, probably a missing revision
 141                                 $diffText = "<p>Can't load revision $newid</p>";
 142                         } else {
 143                                 // Diff output fine, clean up any illegal UTF-8
 144                                 $diffText = UtfNormal\Validator::cleanUp( $diffText );
 145                                 $diffText = self::applyDiffStyle( $diffText );
 146                         }
 147                 } else {
 148                         $rev = Revision::newFromId( $newid );
 149                         if ( $wgFeedDiffCutoff <= 0 || is_null( $rev ) ) {
 150                                 $newContent = ContentHandler::getForTitle( $title )->makeEmptyContent();
 151                         } else {
 152                                 $newContent = $rev->getContent();
 153                         }
 154
 155                         if ( $newContent instanceof TextContent ) {
 156                                 // only textual content has a "source view".
 157                                 $text = $newContent->getText();
 158
 159                                 if ( $wgFeedDiffCutoff <= 0 || strlen( $text ) > $wgFeedDiffCutoff ) {
 160                                         $html = null;
 161                                 } else {
 162                                         $html = nl2br( htmlspecialchars( $text ) );
 163                                 }
 164                         } else {
 165                                 // XXX: we could get an HTML representation of the content via getParserOutput, but that may
 166                                 //     contain JS magic and generally may not be suitable for inclusion in a feed.
 167                                 //     Perhaps Content should have a getDescriptiveHtml method and/or a getSourceText method.
 168                                 // Compare also ApiFeedContributions::feedItemDesc
 169                                 $html = null;
 170                         }
 171
 172                         if ( $html === null ) {
 173                                 // Omit large new page diffs, T31110
 174                                 // Also use diff link for non-textual content
 175                                 $diffText = self::getDiffLink( $title, $newid );
 176                         } else {
 177                                 $diffText = '<p><b>' . wfMessage( 'newpage' )->text() . '</b></p>' .
 178                                         '<div>' . $html . '</div>';
 179                         }
 180                 }
 181                 $completeText .= $diffText;
 182
 183                 return $completeText;
 184         }
 185
 186         /**
 187          * Generates a diff link. Used when the full diff is not wanted for example
 188          * when $wgFeedDiffCutoff is 0.
 189          *
 190          * @param Title $title Title object: used to generate the diff URL
 191          * @param int $newid Newid for this diff
 192          * @param int|null $oldid Oldid for the diff. Null means it is a new article
 193          * @return string
 194          */
 195         protected static function getDiffLink( Title $title, $newid, $oldid = null ) {
 196                 $queryParameters = [ 'diff' => $newid ];
 197                 if ( $oldid != null ) {
 198                         $queryParameters['oldid'] = $oldid;
 199                 }
 200                 $diffUrl = $title->getFullURL( $queryParameters );
 201
 202                 $diffLink = Html::element( 'a', [ 'href' => $diffUrl ],
 203                         wfMessage( 'showdiff' )->inContentLanguage()->text() );
 204
 205                 return $diffLink;
 206         }
 207
 208         /**
 209          * Hacky application of diff styles for the feeds.
 210          * Might be 'cleaner' to use DOM or XSLT or something,
 211          * but *gack* it's a pain in the ass.
 212          *
 213          * @param string $text Diff's HTML output
 214          * @return string Modified HTML
 215          */
 216         public static function applyDiffStyle( $text ) {
 217                 $styles = [
 218                         'diff'             => 'background-color: #fff; color: #222;',
 219                         'diff-otitle'      => 'background-color: #fff; color: #222; text-align: center;',
 220                         'diff-ntitle'      => 'background-color: #fff; color: #222; text-align: center;',
 221                         'diff-addedline'   => 'color: #222; font-size: 88%; border-style: solid; '
 222                                 . 'border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; '
 223                                 . 'vertical-align: top; white-space: pre-wrap;',
 224                         'diff-deletedline' => 'color: #222; font-size: 88%; border-style: solid; '
 225                                 . 'border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; '
 226                                 . 'vertical-align: top; white-space: pre-wrap;',
 227                         'diff-context'     => 'background-color: #f8f9fa; color: #222; font-size: 88%; '
 228                                 . 'border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; '
 229                                 . 'border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;',
 230                         'diffchange'       => 'font-weight: bold; text-decoration: none;',
 231                 ];
 232
 233                 foreach ( $styles as $class => $style ) {
 234                         $text = preg_replace( "/(<[^>]+)class=(['\"])$class\\2([^>]*>)/",
 235                                 "\\1style=\"$style\"\\3", $text );
 236                 }
 237
 238                 return $text;
 239         }
 240
 241 }