FeedUtils.php

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<?php
use MediaWiki\MediaWikiServices;

class FeedUtils {

    public static function checkPurge( $timekey, $key ) {
        global $wgRequest, $wgUser;

        $purge = $wgRequest->getVal( 'action' ) === 'purge';
        // Allow users with 'purge' right to clear feed caches
        if ( $purge && $wgUser->isAllowed( 'purge' ) ) {
            $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
            $cache->delete( $timekey, 1 );
            $cache->delete( $key, 1 );
        }
    }

    public static function checkFeedOutput( $type ) {
        global $wgOut, $wgFeed, $wgFeedClasses;

        if ( !$wgFeed ) {
            $wgOut->addWikiMsg( 'feed-unavailable' );
            return false;
        }

        if ( !isset( $wgFeedClasses[$type] ) ) {
            $wgOut->addWikiMsg( 'feed-invalid' );
            return false;
        }

        return true;
    }

    public static function formatDiff( $row ) {
        $titleObj = Title::makeTitle( $row->rc_namespace, $row->rc_title );
        $timestamp = wfTimestamp( TS_MW, $row->rc_timestamp );
        $actiontext = '';
        if ( $row->rc_type == RC_LOG ) {
            $rcRow = (array)$row; // newFromRow() only accepts arrays for RC rows
            $actiontext = LogFormatter::newFromRow( $rcRow )->getActionText();
        }
        return self::formatDiffRow( $titleObj,
            $row->rc_last_oldid, $row->rc_this_oldid,
            $timestamp,
            $row->rc_deleted & Revision::DELETED_COMMENT
                ? wfMessage( 'rev-deleted-comment' )->escaped()
                : CommentStore::getStore()->getComment( 'rc_comment', $row )->text,
            $actiontext
        );
    }

    public static function formatDiffRow( $title, $oldid, $newid, $timestamp,
        $comment, $actiontext = ''
    ) {
        global $wgFeedDiffCutoff, $wgLang;

        // log entries
        $completeText = '<p>' . implode( ' ',
            array_filter(
                [
                    $actiontext,
                    Linker::formatComment( $comment ) ] ) ) . "</p>\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.
        $anon = new User();
        $accErrors = $title->getUserPermissionsErrors( 'read', $anon, true );

        // Can't diff special pages, unreadable pages or pages with no new revision
        // to compare against: just return the text.
        if ( $title->getNamespace() < 0 || $accErrors || !$newid ) {
            return $completeText;
        }

        if ( $oldid ) {
            $diffText = '';
            // Don't bother generating the diff if we won't be able to show it
            if ( $wgFeedDiffCutoff > 0 ) {
                $rev = Revision::newFromId( $oldid );

                if ( !$rev ) {
                    $diffText = false;
                } else {
                    $context = clone RequestContext::getMain();
                    $context->setTitle( $title );

                    $contentHandler = $rev->getContentHandler();
                    $de = $contentHandler->createDifferenceEngine( $context, $oldid, $newid );
                    $diffText = $de->getDiff(
                        wfMessage( 'previousrevision' )->text(), // hack
                        wfMessage( 'revisionasof',
                            $wgLang->timeanddate( $timestamp ),
                            $wgLang->date( $timestamp ),
                            $wgLang->time( $timestamp ) )->text() );
                }
            }

            if ( $wgFeedDiffCutoff <= 0 || ( strlen( $diffText ) > $wgFeedDiffCutoff ) ) {
                // Omit large diffs
                $diffText = self::getDiffLink( $title, $newid, $oldid );
            } elseif ( $diffText === false ) {
                // Error in diff engine, probably a missing revision
                $diffText = "<p>Can't load revision $newid</p>";
            } else {
                // Diff output fine, clean up any illegal UTF-8
                $diffText = UtfNormal\Validator::cleanUp( $diffText );
                $diffText = self::applyDiffStyle( $diffText );
            }
        } else {
            $rev = Revision::newFromId( $newid );
            if ( $wgFeedDiffCutoff <= 0 || is_null( $rev ) ) {
                $newContent = ContentHandler::getForTitle( $title )->makeEmptyContent();
            } else {
                $newContent = $rev->getContent();
            }

            if ( $newContent instanceof TextContent ) {
                // only textual content has a "source view".
                $text = $newContent->getText();

                if ( $wgFeedDiffCutoff <= 0 || strlen( $text ) > $wgFeedDiffCutoff ) {
                    $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 = '<p><b>' . wfMessage( 'newpage' )->text() . '</b></p>' .
                    '<div>' . $html . '</div>';
            }
        }
        $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: #222;',
            'diff-otitle'      => 'background-color: #fff; color: #222; text-align: center;',
            'diff-ntitle'      => 'background-color: #fff; color: #222; text-align: center;',
            'diff-addedline'   => 'color: #222; 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: #222; 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: #222; 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 ) {
            $text = preg_replace( "/(<[^>]+)class=(['\"])$class\\2([^>]*>)/",
                "\\1style=\"$style\"\\3", $text );
        }

        return $text;
    }

}