FeedUtils.php

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<?php
namespace MediaWiki\Feed;
 
use MediaWiki\Content\TextContent;
use MediaWiki\Context\DerivativeContext;
use MediaWiki\Context\RequestContext;
use MediaWiki\Html\Html;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Output\OutputPage;
use MediaWiki\RecentChanges\RecentChange;
use MediaWiki\Revision\RevisionRecord;
use MediaWiki\Revision\SlotRecord;
use MediaWiki\Title\Title;
use UtfNormal;
use Wikimedia\Timestamp\TimestampFormat as TS;
 
class FeedUtils {
 
    public static function checkFeedOutput( $type, $output ): bool {
        $feed = MediaWikiServices::getInstance()->getMainConfig()->get( MainConfigNames::Feed );
        $feedClasses = MediaWikiServices::getInstance()->getMainConfig()->get( MainConfigNames::FeedClasses );
 
        if ( !$feed ) {
            $output->addWikiMsg( 'feed-unavailable' );
            return false;
        }
 
        if ( !isset( $feedClasses[$type] ) ) {
            $output->addWikiMsg( 'feed-invalid' );
            return false;
        }
 
        return true;
    }
 
    public static function formatDiff( $row, $formattedComment = null ) {
        $titleObj = Title::makeTitle( $row->rc_namespace, $row->rc_title );
        $timestamp = wfTimestamp( TS::MW, $row->rc_timestamp );
        $actiontext = '';
        if ( $row->rc_source === RecentChange::SRC_LOG ) {
            $rcRow = (array)$row; // newFromRow() only accepts arrays for RC rows
            $actiontext = MediaWikiServices::getInstance()->getLogFormatterFactory()
                ->newFromRow( $rcRow )->getActionText();
        }
        if ( $row->rc_deleted & RevisionRecord::DELETED_COMMENT ) {
            $formattedComment = wfMessage( 'rev-deleted-comment' )->escaped();
        } elseif ( $formattedComment === null ) {
            $services = MediaWikiServices::getInstance();
            $formattedComment = $services->getCommentFormatter()->format(
                $services->getCommentStore()->getComment( 'rc_comment', $row )->text );
        }
        return self::formatDiffRow2( $titleObj,
            $row->rc_last_oldid, $row->rc_this_oldid,
            $timestamp,
            $formattedComment,
            $actiontext
        );
    }
 
    public static function formatDiffRow( $title, $oldid, $newid, $timestamp,
        $comment, $actiontext = ''
    ) {
        $formattedComment = MediaWikiServices::getInstance()->getCommentFormatter()
            ->format( $comment );
        return self::formatDiffRow2( $title, $oldid, $newid, $timestamp,
            $formattedComment, $actiontext );
    }
 
    public static function formatDiffRow2(
        $title, $oldid, $newid, $timestamp, $formattedComment, $actiontext = ''
    ) {
        $feedDiffCutoff = MediaWikiServices::getInstance()->getMainConfig()->get( MainConfigNames::FeedDiffCutoff );
 
        // log entries
        $unwrappedText = implode(
            ' ',
            array_filter( [ $actiontext, $formattedComment ] )
        );
        $completeText = Html::rawElement( 'p', [], $unwrappedText ) . "\n";
 
        // NOTE: Check permissions for anonymous users, not current user.
        //       No "privileged" version should end up in the cache.
        //       Most feed readers will not log in anyway.
        $services = MediaWikiServices::getInstance();
        $anon = $services->getUserFactory()->newAnonymous();
        $permManager = $services->getPermissionManager();
        $userCan = $permManager->userCan(
            'read',
            $anon,
            $title
        );
 
        // Can't diff special pages, unreadable pages or pages with no new revision
        // to compare against: just return the text.
        if ( $title->getNamespace() < 0 || !$userCan || !$newid ) {
            return $completeText;
        }
 
        $revLookup = $services->getRevisionLookup();
        $contentHandlerFactory = $services->getContentHandlerFactory();
        if ( $oldid ) {
            $diffText = '';
            // Don't bother generating the diff if we won't be able to show it
            if ( $feedDiffCutoff > 0 ) {
                $revRecord = $revLookup->getRevisionById( $oldid );
 
                if ( !$revRecord ) {
                    $diffText = false;
                } else {
                    $context = new DerivativeContext( RequestContext::getMain() );
                    $context->setTitle( $title );
 
                    $model = $revRecord->getSlot(
                        SlotRecord::MAIN,
                        RevisionRecord::RAW
                    )->getModel();
                    $contentHandler = $contentHandlerFactory->getContentHandler( $model );
                    $de = $contentHandler->createDifferenceEngine( $context, $oldid, $newid );
                    $lang = $context->getLanguage();
                    $user = $context->getUser();
                    $diffText = $de->getDiff(
                        $context->msg( 'previousrevision' )->text(), // hack
                        $context->msg( 'revisionasof',
                            $lang->userTimeAndDate( $timestamp, $user ),
                            $lang->userDate( $timestamp, $user ),
                            $lang->userTime( $timestamp, $user ) )->text() );
                }
            }
 
            if ( $feedDiffCutoff <= 0 || ( strlen( $diffText ) > $feedDiffCutoff ) ) {
                // Omit large diffs
                $diffText = self::getDiffLink( $title, $newid, $oldid );
            } elseif ( $diffText === false ) {
                // Error in diff engine, probably a missing revision
                $diffText = Html::element(
                    'p',
                    [],
                    "Can't load revision $newid"
                );
            } else {
                // Diff output fine, clean up any illegal UTF-8
                $diffText = UtfNormal\Validator::cleanUp( $diffText );
                $diffText = self::applyDiffStyle( $diffText );
            }
        } else {
            $revRecord = $revLookup->getRevisionById( $newid );
            if ( $feedDiffCutoff <= 0 || $revRecord === null ) {
                $newContent = $contentHandlerFactory
                    ->getContentHandler( $title->getContentModel() )
                    ->makeEmptyContent();
            } else {
                $newContent = $revRecord->getContent( SlotRecord::MAIN );
            }
 
            if ( $newContent instanceof TextContent ) {
                // only textual content has a "source view".
                $text = $newContent->getText();
 
                if ( $feedDiffCutoff <= 0 || strlen( $text ) > $feedDiffCutoff ) {
                    $html = null;
                } else {
                    $html = nl2br( htmlspecialchars( $text ) );
                }
            } else {
                // XXX: we could get an HTML representation of the content via getParserOutput, but that may
                //     contain JS magic and generally may not be suitable for inclusion in a feed.
                //     Perhaps Content should have a getDescriptiveHtml method and/or a getSourceText method.
                // Compare also ApiFeedContributions::feedItemDesc
                $html = null;
            }
 
            if ( $html === null ) {
                // Omit large new page diffs, T31110
                // Also use diff link for non-textual content
                $diffText = self::getDiffLink( $title, $newid );
            } else {
                $diffText = Html::rawElement(
                    'p',
                    [],
                    Html::element( 'b', [], wfMessage( 'newpage' )->text() )
                );
                $diffText .= Html::rawElement( 'div', [], $html );
            }
        }
        $completeText .= $diffText;
 
        return $completeText;
    }
 
    protected static function getDiffLink( Title $title, $newid, $oldid = null ) {
        $queryParameters = [ 'diff' => $newid ];
        if ( $oldid != null ) {
            $queryParameters['oldid'] = $oldid;
        }
        $diffUrl = $title->getFullURL( $queryParameters );
 
        $diffLink = Html::element( 'a', [ 'href' => $diffUrl ],
            wfMessage( 'showdiff' )->inContentLanguage()->text() );
 
        return $diffLink;
    }
 
    public static function applyDiffStyle( $text ) {
        $styles = [
            'diff' => 'background-color: #fff; color: #202122;',
            'diff-otitle' => 'background-color: #fff; color: #202122; text-align: center;',
            'diff-ntitle' => 'background-color: #fff; color: #202122; text-align: center;',
            'diff-addedline' => 'color: #202122; font-size: 88%; border-style: solid; '
                . 'border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; '
                . 'vertical-align: top; white-space: pre-wrap;',
            'diff-deletedline' => 'color: #202122; font-size: 88%; border-style: solid; '
                . 'border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; '
                . 'vertical-align: top; white-space: pre-wrap;',
            'diff-context' => 'background-color: #f8f9fa; color: #202122; font-size: 88%; '
                . 'border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; '
                . 'border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;',
            'diffchange' => 'font-weight: bold; text-decoration: none;',
        ];
 
        foreach ( $styles as $class => $style ) {
            $text = preg_replace( '/(<\w+\b[^<>]*)\bclass=([\'"])(?:[^\'"]*\s)?' .
                preg_quote( $class ) . '(?:\s[^\'"]*)?\2(?=[^<>]*>)/',
                '$1style="' . $style . '"', $text );
        }
 
        return $text;
    }
 
}