CoreParserFunctions.php

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<?php
use MediaWiki\Category\Category;
use MediaWiki\Config\ServiceOptions;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Parser\MagicWordFactory;
use MediaWiki\Parser\ParserOutputFlags;
use MediaWiki\Revision\RevisionAccessException;
use MediaWiki\Revision\RevisionRecord;
use MediaWiki\SiteStats\SiteStats;
use MediaWiki\StubObject\StubUserLang;
use MediaWiki\Title\Title;
use Wikimedia\RemexHtml\Tokenizer\Attributes;
use Wikimedia\RemexHtml\Tokenizer\PlainAttributes;
 
class CoreParserFunctions {
    private const MAX_TTS = 900;
 
    public const REGISTER_OPTIONS = [
        // See documentation for the corresponding config options
        MainConfigNames::AllowDisplayTitle,
        MainConfigNames::AllowSlowParserFunctions,
    ];
 
    public static function register( Parser $parser, ServiceOptions $options ) {
        $options->assertRequiredOptions( self::REGISTER_OPTIONS );
        $allowDisplayTitle = $options->get( MainConfigNames::AllowDisplayTitle );
        $allowSlowParserFunctions = $options->get( MainConfigNames::AllowSlowParserFunctions );
 
        # Syntax for arguments (see Parser::setFunctionHook):
        #  "name for lookup in localized magic words array",
        #  function callback,
        #  optional Parser::SFH_NO_HASH to omit the hash from calls (e.g. {{int:...}}
        #    instead of {{#int:...}})
        $noHashFunctions = [
            'ns', 'nse', 'urlencode', 'lcfirst', 'ucfirst', 'lc', 'uc',
            'localurl', 'localurle', 'fullurl', 'fullurle', 'canonicalurl',
            'canonicalurle', 'formatnum', 'grammar', 'gender', 'plural', 'bidi',
            'numberingroup', 'language',
            'padleft', 'padright', 'anchorencode', 'defaultsort', 'filepath',
            'pagesincategory', 'pagesize', 'protectionlevel', 'protectionexpiry',
            # The following are the "parser function" forms of magic
            # variables defined in CoreMagicVariables.  The no-args form will
            # go through the magic variable code path (and be cached); the
            # presence of arguments will cause the parser function form to
            # be invoked. (Note that the actual implementation will pass
            # a Parser object as first argument, in addition to the
            # parser function parameters.)
 
            # For this group, the first parameter to the parser function is
            # "page title", and the no-args form (and the magic variable)
            # defaults to "current page title".
            'pagename', 'pagenamee',
            'fullpagename', 'fullpagenamee',
            'subpagename', 'subpagenamee',
            'rootpagename', 'rootpagenamee',
            'basepagename', 'basepagenamee',
            'talkpagename', 'talkpagenamee',
            'subjectpagename', 'subjectpagenamee',
            'pageid', 'revisionid', 'revisionday',
            'revisionday2', 'revisionmonth', 'revisionmonth1', 'revisionyear',
            'revisiontimestamp',
            'revisionuser',
            'cascadingsources',
            'namespace', 'namespacee', 'namespacenumber', 'talkspace', 'talkspacee',
            'subjectspace', 'subjectspacee',
 
            # More parser functions corresponding to CoreMagicVariables.
            # For this group, the first parameter to the parser function is
            # "raw" (uses the 'raw' format if present) and the no-args form
            # (and the magic variable) defaults to 'not raw'.
            'numberofarticles', 'numberoffiles',
            'numberofusers',
            'numberofactiveusers',
            'numberofpages',
            'numberofadmins',
            'numberofedits',
        ];
        foreach ( $noHashFunctions as $func ) {
            $parser->setFunctionHook( $func, [ __CLASS__, $func ], Parser::SFH_NO_HASH );
        }
 
        $parser->setFunctionHook( 'int', [ __CLASS__, 'intFunction' ], Parser::SFH_NO_HASH );
        $parser->setFunctionHook( 'special', [ __CLASS__, 'special' ] );
        $parser->setFunctionHook( 'speciale', [ __CLASS__, 'speciale' ] );
        $parser->setFunctionHook( 'tag', [ __CLASS__, 'tagObj' ], Parser::SFH_OBJECT_ARGS );
        $parser->setFunctionHook( 'formatdate', [ __CLASS__, 'formatDate' ] );
 
        if ( $allowDisplayTitle ) {
            $parser->setFunctionHook(
                'displaytitle',
                [ __CLASS__, 'displaytitle' ],
                Parser::SFH_NO_HASH
            );
        }
        if ( $allowSlowParserFunctions ) {
            $parser->setFunctionHook(
                'pagesinnamespace',
                [ __CLASS__, 'pagesinnamespace' ],
                Parser::SFH_NO_HASH
            );
        }
    }
 
    public static function intFunction( $parser, $part1 = '', ...$params ) {
        if ( strval( $part1 ) !== '' ) {
            $message = wfMessage( $part1, $params )
                ->inLanguage( $parser->getOptions()->getUserLangObj() );
            return [ $message->plain(), 'noparse' => false ];
        } else {
            return [ 'found' => false ];
        }
    }
 
    public static function formatDate( $parser, $date, $defaultPref = null ) {
        $lang = $parser->getTargetLanguage();
        $df = MediaWikiServices::getInstance()->getDateFormatterFactory()->get( $lang );
 
        $date = trim( $date );
 
        $pref = $parser->getOptions()->getDateFormat();
 
        // Specify a different default date format other than the normal default
        // if the user has 'default' for their setting
        if ( $pref == 'default' && $defaultPref ) {
            $pref = $defaultPref;
        }
 
        $date = $df->reformat( $pref, $date, [ 'match-whole' ] );
        return $date;
    }
 
    public static function ns( $parser, $part1 = '' ) {
        if ( intval( $part1 ) || $part1 == "0" ) {
            $index = intval( $part1 );
        } else {
            $index = $parser->getContentLanguage()->getNsIndex( str_replace( ' ', '_', $part1 ) );
        }
        if ( $index !== false ) {
            return $parser->getContentLanguage()->getFormattedNsText( $index );
        } else {
            return [ 'found' => false ];
        }
    }
 
    public static function nse( $parser, $part1 = '' ) {
        $ret = self::ns( $parser, $part1 );
        if ( is_string( $ret ) ) {
            $ret = wfUrlencode( str_replace( ' ', '_', $ret ) );
        }
        return $ret;
    }
 
    public static function urlencode( $parser, $s = '', $arg = null ) {
        static $magicWords = null;
        if ( $magicWords === null ) {
            $magicWords =
                $parser->getMagicWordFactory()->newArray( [ 'url_path', 'url_query', 'url_wiki' ] );
        }
        switch ( $magicWords->matchStartToEnd( $arg ?? '' ) ) {
            // Encode as though it's a wiki page, '_' for ' '.
            case 'url_wiki':
                $func = 'wfUrlencode';
                $s = str_replace( ' ', '_', $s );
                break;
 
            // Encode for an HTTP Path, '%20' for ' '.
            case 'url_path':
                $func = 'rawurlencode';
                break;
 
            // Encode for HTTP query, '+' for ' '.
            case 'url_query':
            default:
                $func = 'urlencode';
        }
        // See T105242, where the choice to kill markers and various
        // other options were discussed.
        return $func( $parser->killMarkers( $s ) );
    }
 
    public static function lcfirst( $parser, $s = '' ) {
        return $parser->getContentLanguage()->lcfirst( $s );
    }
 
    public static function ucfirst( $parser, $s = '' ) {
        return $parser->getContentLanguage()->ucfirst( $s );
    }
 
    public static function lc( $parser, $s = '' ) {
        return $parser->markerSkipCallback( $s, [ $parser->getContentLanguage(), 'lc' ] );
    }
 
    public static function uc( $parser, $s = '' ) {
        return $parser->markerSkipCallback( $s, [ $parser->getContentLanguage(), 'uc' ] );
    }
 
    public static function localurl( $parser, $s = '', $arg = null ) {
        return self::urlFunction( 'getLocalURL', $s, $arg );
    }
 
    public static function localurle( $parser, $s = '', $arg = null ) {
        $temp = self::urlFunction( 'getLocalURL', $s, $arg );
        if ( !is_string( $temp ) ) {
            return $temp;
        } else {
            return htmlspecialchars( $temp, ENT_COMPAT );
        }
    }
 
    public static function fullurl( $parser, $s = '', $arg = null ) {
        return self::urlFunction( 'getFullURL', $s, $arg );
    }
 
    public static function fullurle( $parser, $s = '', $arg = null ) {
        $temp = self::urlFunction( 'getFullURL', $s, $arg );
        if ( !is_string( $temp ) ) {
            return $temp;
        } else {
            return htmlspecialchars( $temp, ENT_COMPAT );
        }
    }
 
    public static function canonicalurl( $parser, $s = '', $arg = null ) {
        return self::urlFunction( 'getCanonicalURL', $s, $arg );
    }
 
    public static function canonicalurle( $parser, $s = '', $arg = null ) {
        $temp = self::urlFunction( 'getCanonicalURL', $s, $arg );
        if ( !is_string( $temp ) ) {
            return $temp;
        } else {
            return htmlspecialchars( $temp, ENT_COMPAT );
        }
    }
 
    public static function urlFunction( $func, $s = '', $arg = null ) {
        # Due to order of execution of a lot of bits, the values might be encoded
        # before arriving here; if that's true, then the title can't be created
        # and the variable will fail. If we can't get a decent title from the first
        # attempt, url-decode and try for a second.
        $title = Title::newFromText( $s ) ?? Title::newFromURL( urldecode( $s ) );
        if ( $title !== null ) {
            # Convert NS_MEDIA -> NS_FILE
            if ( $title->inNamespace( NS_MEDIA ) ) {
                $title = Title::makeTitle( NS_FILE, $title->getDBkey() );
            }
            if ( $arg !== null ) {
                $text = $title->$func( $arg );
            } else {
                $text = $title->$func();
            }
            return $text;
        } else {
            return [ 'found' => false ];
        }
    }
 
    public static function formatnum( $parser, $num = '', $arg = null ) {
        if ( self::matchAgainstMagicword( $parser->getMagicWordFactory(), 'rawsuffix', $arg ) ) {
            $func = [ $parser->getTargetLanguage(), 'parseFormattedNumber' ];
        } elseif (
            self::matchAgainstMagicword( $parser->getMagicWordFactory(), 'nocommafysuffix', $arg )
        ) {
            $func = [ $parser->getTargetLanguage(), 'formatNumNoSeparators' ];
            $func = self::getLegacyFormatNum( $parser, $func );
        } else {
            $func = [ $parser->getTargetLanguage(), 'formatNum' ];
            $func = self::getLegacyFormatNum( $parser, $func );
        }
        return $parser->markerSkipCallback( $num, $func );
    }
 
    private static function getLegacyFormatNum( $parser, $callback ) {
        // For historic reasons, the formatNum parser function will
        // take arguments which are not actually formatted numbers,
        // which then trigger deprecation warnings in Language::formatNum*.
        // Instead emit a tracking category instead to allow linting.
        return static function ( $number ) use ( $parser, $callback ) {
            $validNumberRe = '(-(?=[\d\.]))?(\d+|(?=\.\d))(\.\d*)?([Ee][-+]?\d+)?';
            if (
                !is_numeric( $number ) &&
                $number !== (string)NAN &&
                $number !== (string)INF &&
                $number !== (string)-INF
            ) {
                $parser->addTrackingCategory( 'nonnumeric-formatnum' );
                // Don't split on NAN/INF in the legacy case since they are
                // likely to be found embedded inside non-numeric text.
                return preg_replace_callback( "/{$validNumberRe}/", static function ( $m ) use ( $callback ) {
                    return call_user_func( $callback, $m[0] );
                }, $number );
            }
            return call_user_func( $callback, $number );
        };
    }
 
    public static function grammar( $parser, $case = '', $word = '' ) {
        $word = $parser->killMarkers( $word );
        return $parser->getTargetLanguage()->convertGrammar( $word, $case );
    }
 
    public static function gender( $parser, $username, ...$forms ) {
        // Some shortcuts to avoid loading user data unnecessarily
        if ( count( $forms ) === 0 ) {
            return '';
        } elseif ( count( $forms ) === 1 ) {
            return $forms[0];
        }
 
        $username = trim( $username );
 
        $userOptionsLookup = MediaWikiServices::getInstance()->getUserOptionsLookup();
        $gender = $userOptionsLookup->getDefaultOption( 'gender' );
 
        // allow prefix and normalize (e.g. "&#42;foo" -> "*foo" ).
        $title = Title::newFromText( $username, NS_USER );
 
        if ( $title && $title->inNamespace( NS_USER ) ) {
            $username = $title->getText();
        }
 
        // check parameter, or use the ParserOptions if in interface message
        $user = User::newFromName( $username );
        $genderCache = MediaWikiServices::getInstance()->getGenderCache();
        if ( $user ) {
            $gender = $genderCache->getGenderOf( $user, __METHOD__ );
        } elseif ( $username === '' && $parser->getOptions()->getInterfaceMessage() ) {
            $gender = $genderCache->getGenderOf( $parser->getOptions()->getUserIdentity(), __METHOD__ );
        }
        $ret = $parser->getTargetLanguage()->gender( $gender, $forms );
        return $ret;
    }
 
    public static function plural( $parser, $text = '', ...$forms ) {
        $text = $parser->getTargetLanguage()->parseFormattedNumber( $text );
        settype( $text, ctype_digit( $text ) ? 'int' : 'float' );
        // @phan-suppress-next-line PhanTypeMismatchArgument Phan does not handle settype
        return $parser->getTargetLanguage()->convertPlural( $text, $forms );
    }
 
    public static function bidi( $parser, $text = '' ) {
        return $parser->getTargetLanguage()->embedBidi( $text );
    }
 
    public static function displaytitle( $parser, $text = '', $uarg = '' ) {
        $restrictDisplayTitle = MediaWikiServices::getInstance()->getMainConfig()
            ->get( MainConfigNames::RestrictDisplayTitle );
 
        static $magicWords = null;
        if ( $magicWords === null ) {
            $magicWords = $parser->getMagicWordFactory()->newArray(
                [ 'displaytitle_noerror', 'displaytitle_noreplace' ] );
        }
        $arg = $magicWords->matchStartToEnd( $uarg );
 
        // parse a limited subset of wiki markup (just the single quote items)
        $text = $parser->doQuotes( $text );
 
        // remove stripped text (e.g. the UNIQ-QINU stuff) that was generated by tag extensions/whatever
        $text = $parser->killMarkers( $text );
 
        // See T28547 for rationale for this processing.
        // list of disallowed tags for DISPLAYTITLE
        // these will be escaped even though they are allowed in normal wiki text
        $bad = [ 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'div', 'blockquote', 'ol', 'ul', 'li', 'hr',
            'table', 'tr', 'th', 'td', 'dl', 'dd', 'caption', 'p', 'ruby', 'rb', 'rt', 'rtc', 'rp', 'br' ];
 
        // disallow some styles that could be used to bypass $wgRestrictDisplayTitle
        if ( $restrictDisplayTitle ) {
            // This code is tested with the cases marked T28547 in
            // parserTests.txt
            $htmlTagsCallback = static function ( Attributes $attr ): Attributes {
                $decoded = $attr->getValues();
 
                if ( isset( $decoded['style'] ) ) {
                    // this is called later anyway, but we need it right now for the regexes below to be safe
                    // calling it twice doesn't hurt
                    $decoded['style'] = Sanitizer::checkCss( $decoded['style'] );
 
                    if ( preg_match( '/(display|user-select|visibility)\s*:/i', $decoded['style'] ) ) {
                        $decoded['style'] = '/* attempt to bypass $wgRestrictDisplayTitle */';
                    }
                }
 
                return new PlainAttributes( $decoded );
            };
        } else {
            $htmlTagsCallback = null;
        }
 
        // only requested titles that normalize to the actual title are allowed through
        // if $wgRestrictDisplayTitle is true (it is by default)
        // mimic the escaping process that occurs in OutputPage::setPageTitle
        $text = Sanitizer::removeSomeTags( $text, [
            'attrCallback' => $htmlTagsCallback,
            'removeTags' => $bad,
        ] );
        $title = Title::newFromText( Sanitizer::stripAllTags( $text ) );
        // Decode entities in $text the same way that Title::newFromText does
        $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 
        if ( !$restrictDisplayTitle ||
            ( $title instanceof Title
            && !$title->hasFragment()
            && $title->equals( $parser->getTitle() ) )
        ) {
            $old = $parser->getOutput()->getPageProperty( 'displaytitle' );
            if ( $old === null || $arg !== 'displaytitle_noreplace' ) {
                $parser->getOutput()->setDisplayTitle( $text );
            }
            if ( $old !== null && $old !== $text && !$arg ) {
 
                $converter = $parser->getTargetLanguageConverter();
                return '<span class="error">' .
                    $parser->msg( 'duplicate-displaytitle',
                        // Message should be parsed, but these params should only be escaped.
                        $converter->markNoConversion( wfEscapeWikiText( $old ) ),
                        $converter->markNoConversion( wfEscapeWikiText( $filteredText ) )
                    )->text() .
                    '</span>';
            } else {
                return '';
            }
        } else {
            $parser->getOutput()->addWarningMsg(
                'restricted-displaytitle',
                // Message should be parsed, but this param should only be escaped.
                Message::plaintextParam( $filteredText )
            );
            $parser->addTrackingCategory( 'restricted-displaytitle-ignored' );
        }
    }
 
    private static function matchAgainstMagicword(
        MagicWordFactory $magicWordFactory, $magicword, $value
    ) {
        $value = trim( strval( $value ) );
        if ( $value === '' ) {
            return false;
        }
        $mwObject = $magicWordFactory->get( $magicword );
        return $mwObject->matchStartToEnd( $value );
    }
 
    public static function formatRaw(
        $num, $raw, $language, MagicWordFactory $magicWordFactory = null
    ) {
        if ( $raw !== null && $raw !== '' ) {
            if ( !$magicWordFactory ) {
                $magicWordFactory = MediaWikiServices::getInstance()->getMagicWordFactory();
            }
            if ( self::matchAgainstMagicword( $magicWordFactory, 'rawsuffix', $raw ) ) {
                return (string)$num;
            }
        }
        return $language->formatNum( $num );
    }
 
    public static function numberofpages( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::pages(), $raw, $parser->getTargetLanguage() );
    }
 
    public static function numberofusers( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::users(), $raw, $parser->getTargetLanguage() );
    }
 
    public static function numberofactiveusers( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::activeUsers(), $raw, $parser->getTargetLanguage() );
    }
 
    public static function numberofarticles( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::articles(), $raw, $parser->getTargetLanguage() );
    }
 
    public static function numberoffiles( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::images(), $raw, $parser->getTargetLanguage() );
    }
 
    public static function numberofadmins( $parser, $raw = null ) {
        return self::formatRaw(
            SiteStats::numberingroup( 'sysop' ),
            $raw,
            $parser->getTargetLanguage()
        );
    }
 
    public static function numberofedits( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::edits(), $raw, $parser->getTargetLanguage() );
    }
 
    public static function pagesinnamespace( $parser, $namespace = 0, $raw = null ) {
        return self::formatRaw(
            SiteStats::pagesInNs( intval( $namespace ) ),
            $raw,
            $parser->getTargetLanguage()
        );
    }
 
    public static function numberingroup( $parser, $name = '', $raw = null ) {
        return self::formatRaw(
            SiteStats::numberingroup( strtolower( $name ) ),
            $raw,
            $parser->getTargetLanguage()
        );
    }
 
    private static function makeTitle( Parser $parser, ?string $t ) {
        if ( $t === null ) {
            // For consistency with magic variable forms
            $title = $parser->getTitle();
        } else {
            $title = Title::newFromText( $t );
        }
        return $title;
    }
 
    public static function namespace( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return str_replace( '_', ' ', $t->getNsText() );
    }
 
    public static function mwnamespace( $parser, $title = null ) {
        wfDeprecated( __METHOD__, '1.39' );
        return self::namespace( $parser, $title );
    }
 
    public static function namespacee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfUrlencode( $t->getNsText() );
    }
 
    public static function namespacenumber( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return (string)$t->getNamespace();
    }
 
    public static function talkspace( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null || !$t->canHaveTalkPage() ) {
            return '';
        }
        return str_replace( '_', ' ', $t->getTalkNsText() );
    }
 
    public static function talkspacee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null || !$t->canHaveTalkPage() ) {
            return '';
        }
        return wfUrlencode( $t->getTalkNsText() );
    }
 
    public static function subjectspace( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return str_replace( '_', ' ', $t->getSubjectNsText() );
    }
 
    public static function subjectspacee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfUrlencode( $t->getSubjectNsText() );
    }
 
    public static function pagename( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getText() );
    }
 
    public static function pagenamee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getPartialURL() );
    }
 
    public static function fullpagename( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getPrefixedText() );
    }
 
    public static function fullpagenamee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getPrefixedURL() );
    }
 
    public static function subpagename( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getSubpageText() );
    }
 
    public static function subpagenamee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getSubpageUrlForm() );
    }
 
    public static function rootpagename( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getRootText() );
    }
 
    public static function rootpagenamee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( wfUrlencode( str_replace( ' ', '_', $t->getRootText() ) ) );
    }
 
    public static function basepagename( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getBaseText() );
    }
 
    public static function basepagenamee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( wfUrlencode( str_replace( ' ', '_', $t->getBaseText() ) ) );
    }
 
    public static function talkpagename( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null || !$t->canHaveTalkPage() ) {
            return '';
        }
        return wfEscapeWikiText( $t->getTalkPage()->getPrefixedText() );
    }
 
    public static function talkpagenamee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null || !$t->canHaveTalkPage() ) {
            return '';
        }
        return wfEscapeWikiText( $t->getTalkPage()->getPrefixedURL() );
    }
 
    public static function subjectpagename( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getSubjectPage()->getPrefixedText() );
    }
 
    public static function subjectpagenamee( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return wfEscapeWikiText( $t->getSubjectPage()->getPrefixedURL() );
    }
 
    public static function pagesincategory( $parser, $name = '', $arg1 = '', $arg2 = '' ) {
        static $magicWords = null;
        if ( $magicWords === null ) {
            $magicWords = $parser->getMagicWordFactory()->newArray( [
                'pagesincategory_all',
                'pagesincategory_pages',
                'pagesincategory_subcats',
                'pagesincategory_files'
            ] );
        }
        static $cache = [];
 
        // split the given option to its variable
        if ( self::matchAgainstMagicword( $parser->getMagicWordFactory(), 'rawsuffix', $arg1 ) ) {
            // {{pagesincategory:|raw[|type]}}
            $raw = $arg1;
            $type = $magicWords->matchStartToEnd( $arg2 );
        } else {
            // {{pagesincategory:[|type[|raw]]}}
            $type = $magicWords->matchStartToEnd( $arg1 );
            $raw = $arg2;
        }
        if ( !$type ) { // backward compatibility
            $type = 'pagesincategory_all';
        }
 
        $title = Title::makeTitleSafe( NS_CATEGORY, $name );
        if ( !$title ) { # invalid title
            return self::formatRaw( 0, $raw, $parser->getTargetLanguage() );
        }
        $languageConverter = MediaWikiServices::getInstance()
            ->getLanguageConverterFactory()
            ->getLanguageConverter( $parser->getContentLanguage() );
        $languageConverter->findVariantLink( $name, $title, true );
 
        // Normalize name for cache
        $name = $title->getDBkey();
 
        if ( !isset( $cache[$name] ) ) {
            $category = Category::newFromTitle( $title );
 
            $allCount = $subcatCount = $fileCount = $pageCount = 0;
            if ( $parser->incrementExpensiveFunctionCount() ) {
                $allCount = $category->getMemberCount();
                $subcatCount = $category->getSubcatCount();
                $fileCount = $category->getFileCount();
                $pageCount = $category->getPageCount( Category::COUNT_CONTENT_PAGES );
            }
            $cache[$name]['pagesincategory_all'] = $allCount;
            $cache[$name]['pagesincategory_pages'] = $pageCount;
            $cache[$name]['pagesincategory_subcats'] = $subcatCount;
            $cache[$name]['pagesincategory_files'] = $fileCount;
        }
 
        $count = $cache[$name][$type];
        return self::formatRaw( $count, $raw, $parser->getTargetLanguage() );
    }
 
    public static function pagesize( $parser, $page = '', $raw = null ) {
        $title = Title::newFromText( $page );
 
        if ( !is_object( $title ) ) {
            return self::formatRaw( 0, $raw, $parser->getTargetLanguage() );
        }
 
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $title, ParserOutputFlags::VARY_REVISION_SHA1 );
        $length = $rev ? $rev->getSize() : 0;
        if ( $length === null ) {
            // We've had bugs where rev_len was not being recorded for empty pages, see T135414
            $length = 0;
        }
        return self::formatRaw( $length, $raw, $parser->getTargetLanguage() );
    }
 
    public static function protectionlevel( $parser, $type = '', $title = '' ) {
        $titleObject = Title::newFromText( $title ) ?? $parser->getTitle();
        $restrictionStore = MediaWikiServices::getInstance()->getRestrictionStore();
        if ( $restrictionStore->areRestrictionsLoaded( $titleObject ) || $parser->incrementExpensiveFunctionCount() ) {
            $restrictions = $restrictionStore->getRestrictions( $titleObject, strtolower( $type ) );
            # RestrictionStore::getRestrictions returns an array, its possible it may have
            # multiple values in the future
            return implode( ',', $restrictions );
        }
        return '';
    }
 
    public static function protectionexpiry( $parser, $type = '', $title = '' ) {
        $titleObject = Title::newFromText( $title ) ?? $parser->getTitle();
        $restrictionStore = MediaWikiServices::getInstance()->getRestrictionStore();
        if ( $restrictionStore->areRestrictionsLoaded( $titleObject ) || $parser->incrementExpensiveFunctionCount() ) {
            // getRestrictionExpiry() returns null on invalid type; trying to
            // match protectionlevel() function that returns empty string instead
            return $restrictionStore->getRestrictionExpiry( $titleObject, strtolower( $type ) ) ?? '';
        }
        return '';
    }
 
    public static function language( $parser, $code = '', $inLanguage = '' ) {
        $code = strtolower( $code );
        $inLanguage = strtolower( $inLanguage );
        $lang = MediaWikiServices::getInstance()
            ->getLanguageNameUtils()
            ->getLanguageName( $code, $inLanguage );
        return $lang !== '' ? $lang : LanguageCode::bcp47( $code );
    }
 
    public static function pad(
        $parser, $string, $length, $padding = '0', $direction = STR_PAD_RIGHT
    ) {
        $padding = $parser->killMarkers( $padding );
        $lengthOfPadding = mb_strlen( $padding );
        if ( $lengthOfPadding == 0 ) {
            return $string;
        }
 
        # The remaining length to add counts down to 0 as padding is added
        $length = min( (int)$length, 500 ) - mb_strlen( $string );
        if ( $length <= 0 ) {
            // Nothing to add
            return $string;
        }
 
        # $finalPadding is just $padding repeated enough times so that
        # mb_strlen( $string ) + mb_strlen( $finalPadding ) == $length
        $finalPadding = '';
        while ( $length > 0 ) {
            # If $length < $lengthofPadding, truncate $padding so we get the
            # exact length desired.
            $finalPadding .= mb_substr( $padding, 0, $length );
            $length -= $lengthOfPadding;
        }
 
        if ( $direction == STR_PAD_LEFT ) {
            return $finalPadding . $string;
        } else {
            return $string . $finalPadding;
        }
    }
 
    public static function padleft( $parser, $string = '', $length = 0, $padding = '0' ) {
        return self::pad( $parser, $string, $length, $padding, STR_PAD_LEFT );
    }
 
    public static function padright( $parser, $string = '', $length = 0, $padding = '0' ) {
        return self::pad( $parser, $string, $length, $padding );
    }
 
    public static function anchorencode( $parser, $text ) {
        $text = $parser->killMarkers( $text );
        $section = (string)substr( $parser->guessSectionNameFromWikiText( $text ), 1 );
        return Sanitizer::safeEncodeAttribute( $section );
    }
 
    public static function special( $parser, $text ) {
        [ $page, $subpage ] = MediaWikiServices::getInstance()->getSpecialPageFactory()->
            resolveAlias( $text );
        if ( $page ) {
            $title = SpecialPage::getTitleFor( $page, $subpage );
            return $title->getPrefixedText();
        } else {
            // unknown special page, just use the given text as its title, if at all possible
            $title = Title::makeTitleSafe( NS_SPECIAL, $text );
            return $title ? $title->getPrefixedText() : self::special( $parser, 'Badtitle' );
        }
    }
 
    public static function speciale( $parser, $text ) {
        return wfUrlencode( str_replace( ' ', '_', self::special( $parser, $text ) ) );
    }
 
    public static function defaultsort( $parser, $text, $uarg = '' ) {
        static $magicWords = null;
        if ( $magicWords === null ) {
            $magicWords = $parser->getMagicWordFactory()->newArray(
                [ 'defaultsort_noerror', 'defaultsort_noreplace' ] );
        }
        $arg = $magicWords->matchStartToEnd( $uarg );
 
        $text = trim( $text );
        if ( strlen( $text ) == 0 ) {
            return '';
        }
        $old = $parser->getOutput()->getPageProperty( 'defaultsort' );
        if ( $old === null || $arg !== 'defaultsort_noreplace' ) {
            $parser->getOutput()->setPageProperty( 'defaultsort', $text );
        }
 
        if ( $old === null || $old == $text || $arg ) {
            return '';
        } else {
            $converter = $parser->getTargetLanguageConverter();
            return '<span class="error">' .
                $parser->msg( 'duplicate-defaultsort',
                    // Message should be parsed, but these params should only be escaped.
                    $converter->markNoConversion( wfEscapeWikiText( $old ) ),
                    $converter->markNoConversion( wfEscapeWikiText( $text ) )
                )->text() .
                '</span>';
        }
    }
 
    public static function filepath( $parser, $name = '', $argA = '', $argB = '' ) {
        $file = MediaWikiServices::getInstance()->getRepoGroup()->findFile( $name );
 
        if ( $argA == 'nowiki' ) {
            // {{filepath: | option [| size] }}
            $isNowiki = true;
            $parsedWidthParam = Parser::parseWidthParam( $argB );
        } else {
            // {{filepath: [| size [|option]] }}
            $parsedWidthParam = Parser::parseWidthParam( $argA );
            $isNowiki = ( $argB == 'nowiki' );
        }
 
        if ( $file ) {
            $url = $file->getFullUrl();
 
            // If a size is requested...
            if ( count( $parsedWidthParam ) ) {
                $mto = $file->transform( $parsedWidthParam );
                // ... and we can
                if ( $mto && !$mto->isError() ) {
                    // ... change the URL to point to a thumbnail.
                    $url = wfExpandUrl( $mto->getUrl(), PROTO_RELATIVE );
                }
            }
            if ( $isNowiki ) {
                return [ $url, 'nowiki' => true ];
            }
            return $url;
        } else {
            return '';
        }
    }
 
    public static function tagObj( $parser, $frame, $args ) {
        if ( !count( $args ) ) {
            return '';
        }
        $tagName = strtolower( trim( $frame->expand( array_shift( $args ) ) ) );
        $processNowiki = $parser->tagNeedsNowikiStrippedInTagPF( $tagName ) ? PPFrame::PROCESS_NOWIKI : 0;
 
        if ( count( $args ) ) {
            $inner = $frame->expand( array_shift( $args ), $processNowiki );
        } else {
            $inner = null;
        }
 
        $attributes = [];
        foreach ( $args as $arg ) {
            $bits = $arg->splitArg();
            if ( strval( $bits['index'] ) === '' ) {
                $name = trim( $frame->expand( $bits['name'], PPFrame::STRIP_COMMENTS ) );
                $value = trim( $frame->expand( $bits['value'] ) );
                if ( preg_match( '/^(?:["\'](.+)["\']|""|\'\')$/s', $value, $m ) ) {
                    $value = $m[1] ?? '';
                }
                $attributes[$name] = $value;
            }
        }
 
        $stripList = $parser->getStripList();
        if ( !in_array( $tagName, $stripList ) ) {
            // we can't handle this tag (at least not now), so just re-emit it as an ordinary tag
            $attrText = '';
            foreach ( $attributes as $name => $value ) {
                $attrText .= ' ' . htmlspecialchars( $name ) .
                    '="' . htmlspecialchars( $value, ENT_COMPAT ) . '"';
            }
            if ( $inner === null ) {
                return "<$tagName$attrText/>";
            }
            return "<$tagName$attrText>$inner</$tagName>";
        }
 
        $params = [
            'name' => $tagName,
            'inner' => $inner,
            'attributes' => $attributes,
            'close' => "</$tagName>",
        ];
        return $parser->extensionSubstitution( $params, $frame );
    }
 
    private static function getCachedRevisionObject( $parser, $title, $vary ) {
        if ( !$title ) {
            return null;
        }
 
        $revisionRecord = null;
 
        $isSelfReferential = $title->equals( $parser->getTitle() );
        if ( $isSelfReferential ) {
            // Revision is for the same title that is currently being parsed. Only use the last
            // saved revision, regardless of Parser::getRevisionId() or fake revision injection
            // callbacks against the current title.
 
            // FIXME (T318278): the above is the intention, but doesn't
            // describe the actual current behavior of this code, since
            // ->isCurrent() for the last saved revision will return
            // false so we're going to fall through and end up calling
            // ->getCurrentRevisionRecordOfTitle().
            $parserRevisionRecord = $parser->getRevisionRecordObject();
            if ( $parserRevisionRecord && $parserRevisionRecord->isCurrent() ) {
                $revisionRecord = $parserRevisionRecord;
            }
        }
 
        $parserOutput = $parser->getOutput();
        if ( !$revisionRecord ) {
            if (
                !$parser->isCurrentRevisionOfTitleCached( $title ) &&
                !$parser->incrementExpensiveFunctionCount()
            ) {
                return null; // not allowed
            }
            // Get the current revision, ignoring Parser::getRevisionId() being null/old
            $revisionRecord = $parser->fetchCurrentRevisionRecordOfTitle( $title );
            if ( !$revisionRecord ) {
                // Convert `false` error return to `null`
                $revisionRecord = null;
            }
            // Register dependency in templatelinks
            $parserOutput->addTemplate(
                $title,
                $revisionRecord ? $revisionRecord->getPageId() : 0,
                $revisionRecord ? $revisionRecord->getId() : 0
            );
        }
 
        if ( $isSelfReferential ) {
            wfDebug( __METHOD__ . ": used current revision, setting $vary" );
            // Upon page save, the result of the parser function using this might change
            $parserOutput->setOutputFlag( $vary );
            if ( $vary === ParserOutputFlags::VARY_REVISION_SHA1 && $revisionRecord ) {
                try {
                    $sha1 = $revisionRecord->getSha1();
                } catch ( RevisionAccessException $e ) {
                    $sha1 = null;
                }
                $parserOutput->setRevisionUsedSha1Base36( $sha1 );
            }
        }
 
        return $revisionRecord;
    }
 
    public static function pageid( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( !$t ) {
            return '';
        } elseif ( !$t->canExist() || $t->isExternal() ) {
            return 0; // e.g. special page or interwiki link
        }
 
        $parserOutput = $parser->getOutput();
 
        if ( $t->equals( $parser->getTitle() ) ) {
            // Revision is for the same title that is currently being parsed.
            // Use the title from Parser in case a new page ID was injected into it.
            $parserOutput->setOutputFlag( ParserOutputFlags::VARY_PAGE_ID );
            $id = $parser->getTitle()->getArticleID();
            if ( $id ) {
                $parserOutput->setSpeculativePageIdUsed( $id );
            }
 
            return $id;
        }
 
        // Check the link cache for the title
        $linkCache = MediaWikiServices::getInstance()->getLinkCache();
        $pdbk = $t->getPrefixedDBkey();
        $id = $linkCache->getGoodLinkID( $pdbk );
        if ( $id != 0 || $linkCache->isBadLink( $pdbk ) ) {
            $parserOutput->addLink( $t, $id );
 
            return $id;
        }
 
        // We need to load it from the DB, so mark expensive
        if ( $parser->incrementExpensiveFunctionCount() ) {
            $id = $t->getArticleID();
            $parserOutput->addLink( $t, $id );
 
            return $id;
        }
 
        return null;
    }
 
    public static function revisionid( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
 
        $services = MediaWikiServices::getInstance();
        if (
            $t->equals( $parser->getTitle() ) &&
            $services->getMainConfig()->get( MainConfigNames::MiserMode ) &&
            !$parser->getOptions()->getInterfaceMessage() &&
            // @TODO: disallow this word on all namespaces (T235957)
            $services->getNamespaceInfo()->isSubject( $t->getNamespace() )
        ) {
            // Use a stub result instead of the actual revision ID in order to avoid
            // double parses on page save but still allow preview detection (T137900)
            if ( $parser->getRevisionId() || $parser->getOptions()->getSpeculativeRevId() ) {
                return '-';
            } else {
                $parser->getOutput()->setOutputFlag( ParserOutputFlags::VARY_REVISION_EXISTS );
                return '';
            }
        }
        // Fetch revision from cache/database and return the value.
        // Inform the edit saving system that getting the canonical output
        // after revision insertion requires a parse that used that exact
        // revision ID.
        if ( $t->equals( $parser->getTitle() ) && $title === null ) {
            // special handling for no-arg case: use speculative rev id
            // for current page.
            $parser->getOutput()->setOutputFlag( ParserOutputFlags::VARY_REVISION_ID );
            $id = $parser->getRevisionId();
            if ( $id === 0 ) {
                $rev = $parser->getRevisionRecordObject();
                if ( $rev ) {
                    $id = $rev->getId();
                }
            }
            if ( !$id ) {
                $id = $parser->getOptions()->getSpeculativeRevId();
                if ( $id ) {
                    $parser->getOutput()->setSpeculativeRevIdUsed( $id );
                }
            }
            return (string)$id;
        }
        $rev = self::getCachedRevisionObject( $parser, $t, ParserOutputFlags::VARY_REVISION_ID );
        return $rev ? $rev->getId() : '';
    }
 
    private static function getRevisionTimestampSubstring(
        Parser $parser,
        Title $title,
        int $start,
        int $len,
        int $mtts
    ): string {
        // If fetching the revision timestamp of the current page, substitute the
        // speculative timestamp to be used when this revision is saved.  This
        // avoids having to invalidate the cache immediately by assuming the "last
        // saved revision" will in fact be this one.
        // Don't do this for interface messages (eg, edit notices) however; in that
        // case fall through and use the actual timestamp of the last saved revision.
        if ( $title->equals( $parser->getTitle() ) && !$parser->getOptions()->getInterfaceMessage() ) {
            // Get the timezone-adjusted timestamp to be used for this revision
            $resNow = substr( $parser->getRevisionTimestamp(), $start, $len );
            // Possibly set vary-revision if there is not yet an associated revision
            if ( !$parser->getRevisionRecordObject() ) {
                // Get the timezone-adjusted timestamp $mtts seconds in the future.
                // This future is relative to the current time and not that of the
                // parser options. The rendered timestamp can be compared to that
                // of the timestamp specified by the parser options.
                $resThen = substr(
                    $parser->getContentLanguage()->userAdjust( wfTimestamp( TS_MW, time() + $mtts ), '' ),
                    $start,
                    $len
                );
 
                if ( $resNow !== $resThen ) {
                    // Inform the edit saving system that getting the canonical output after
                    // revision insertion requires a parse that used an actual revision timestamp
                    $parser->getOutput()->setOutputFlag( ParserOutputFlags::VARY_REVISION_TIMESTAMP );
                }
            }
 
            return $resNow;
        } else {
            $rev = self::getCachedRevisionObject( $parser, $title, ParserOutputFlags::VARY_REVISION_TIMESTAMP );
            if ( !$rev ) {
                return '';
            }
            $resNow = substr(
                $parser->getContentLanguage()->userAdjust( $rev->getTimestamp(), '' ), $start, $len
            );
            return $resNow;
        }
    }
 
    public static function revisionday( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return strval( (int)self::getRevisionTimestampSubstring(
            $parser, $t, 6, 2, self::MAX_TTS
        ) );
    }
 
    public static function revisionday2( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return self::getRevisionTimestampSubstring(
            $parser, $t, 6, 2, self::MAX_TTS
        );
    }
 
    public static function revisionmonth( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return self::getRevisionTimestampSubstring(
            $parser, $t, 4, 2, self::MAX_TTS
        );
    }
 
    public static function revisionmonth1( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return strval( (int)self::getRevisionTimestampSubstring(
            $parser, $t, 4, 2, self::MAX_TTS
        ) );
    }
 
    public static function revisionyear( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return self::getRevisionTimestampSubstring(
            $parser, $t, 0, 4, self::MAX_TTS
        );
    }
 
    public static function revisiontimestamp( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        return self::getRevisionTimestampSubstring(
            $parser, $t, 0, 14, self::MAX_TTS
        );
    }
 
    public static function revisionuser( $parser, $title = null ) {
        $t = self::makeTitle( $parser, $title );
        if ( $t === null ) {
            return '';
        }
        // VARY_USER informs the edit saving system that getting the canonical
        // output after revision insertion requires a parse that used the
        // actual user ID.
        if ( $t->equals( $parser->getTitle() ) ) {
            // Fall back to Parser's "revision user" for the current title
            $parser->getOutput()->setOutputFlag( ParserOutputFlags::VARY_USER );
            // Note that getRevisionUser() can return null; we need to
            // be sure to cast this to (an empty) string, since returning
            // null means "magic variable not handled".
            return (string)$parser->getRevisionUser();
        }
        // Fetch revision from cache/database and return the value.
        $rev = self::getCachedRevisionObject( $parser, $t, ParserOutputFlags::VARY_USER );
        $user = ( $rev !== null ) ? $rev->getUser() : null;
        return $user ? $user->getName() : '';
    }
 
    public static function cascadingsources( $parser, $title = '' ) {
        $titleObject = Title::newFromText( $title ) ?? $parser->getTitle();
        $restrictionStore = MediaWikiServices::getInstance()->getRestrictionStore();
        if ( $restrictionStore->areCascadeProtectionSourcesLoaded( $titleObject )
            || $parser->incrementExpensiveFunctionCount()
        ) {
            $names = [];
            $sources = $restrictionStore->getCascadeProtectionSources( $titleObject );
            $titleFormatter = MediaWikiServices::getInstance()->getTitleFormatter();
            foreach ( $sources[0] as $sourcePageIdentity ) {
                $names[] = $titleFormatter->getPrefixedText( $sourcePageIdentity );
            }
            return implode( '|', $names );
        }
        return '';
    }
}