CoreParserFunctions.php

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<?php
class CoreParserFunctions {
    public static function register( $parser ) {
        global $wgAllowDisplayTitle, $wgAllowSlowParserFunctions;

        # 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',
            'numberofpages', 'numberofusers', 'numberofactiveusers',
            'numberofarticles', 'numberoffiles', 'numberofadmins',
            'numberingroup', 'numberofedits', 'language',
            'padleft', 'padright', 'anchorencode', 'defaultsort', 'filepath',
            'pagesincategory', 'pagesize', 'protectionlevel', 'protectionexpiry',
            'namespacee', 'namespacenumber', 'talkspace', 'talkspacee',
            'subjectspace', 'subjectspacee', 'pagename', 'pagenamee',
            'fullpagename', 'fullpagenamee', 'rootpagename', 'rootpagenamee',
            'basepagename', 'basepagenamee', 'subpagename', 'subpagenamee',
            'talkpagename', 'talkpagenamee', 'subjectpagename',
            'subjectpagenamee', 'pageid', 'revisionid', 'revisionday',
            'revisionday2', 'revisionmonth', 'revisionmonth1', 'revisionyear',
            'revisiontimestamp', 'revisionuser', 'cascadingsources',
        ];
        foreach ( $noHashFunctions as $func ) {
            $parser->setFunctionHook( $func, [ __CLASS__, $func ], Parser::SFH_NO_HASH );
        }

        $parser->setFunctionHook(
            'namespace',
            [ __CLASS__, 'mwnamespace' ],
            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 ( $wgAllowDisplayTitle ) {
            $parser->setFunctionHook(
                'displaytitle',
                [ __CLASS__, 'displaytitle' ],
                Parser::SFH_NO_HASH
            );
        }
        if ( $wgAllowSlowParserFunctions ) {
            $parser->setFunctionHook(
                'pagesinnamespace',
                [ __CLASS__, 'pagesinnamespace' ],
                Parser::SFH_NO_HASH
            );
        }
    }

    public static function intFunction( $parser, $part1 = '' /*, ... */ ) {
        if ( strval( $part1 ) !== '' ) {
            $args = array_slice( func_get_args(), 2 );
            $message = wfMessage( $part1, $args )
                ->inLanguage( $parser->getOptions()->getUserLangObj() );
            if ( !$message->exists() ) {
                // When message does not exists, the message name is surrounded by angle
                // and can result in a tag, therefore escape the angles
                return $message->escaped();
            }
            return [ $message->plain(), 'noparse' => false ];
        } else {
            return [ 'found' => false ];
        }
    }

    public static function formatDate( $parser, $date, $defaultPref = null ) {
        $lang = $parser->getFunctionLang();
        $df = DateFormatter::getInstance( $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 = '' ) {
        global $wgContLang;
        if ( intval( $part1 ) || $part1 == "0" ) {
            $index = intval( $part1 );
        } else {
            $index = $wgContLang->getNsIndex( str_replace( ' ', '_', $part1 ) );
        }
        if ( $index !== false ) {
            return $wgContLang->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 ( is_null( $magicWords ) ) {
            $magicWords = new MagicWordArray( [ '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 = '' ) {
        global $wgContLang;
        return $wgContLang->lcfirst( $s );
    }

    public static function ucfirst( $parser, $s = '' ) {
        global $wgContLang;
        return $wgContLang->ucfirst( $s );
    }

    public static function lc( $parser, $s = '' ) {
        global $wgContLang;
        return $parser->markerSkipCallback( $s, [ $wgContLang, 'lc' ] );
    }

    public static function uc( $parser, $s = '' ) {
        global $wgContLang;
        return $parser->markerSkipCallback( $s, [ $wgContLang, '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 );
        }
    }

    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 );
        }
    }

    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 );
        }
    }

    public static function urlFunction( $func, $s = '', $arg = null ) {
        $title = Title::newFromText( $s );
        # 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.
        if ( is_null( $title ) ) {
            $title = Title::newFromURL( urldecode( $s ) );
        }
        if ( !is_null( $title ) ) {
            # Convert NS_MEDIA -> NS_FILE
            if ( $title->getNamespace() == NS_MEDIA ) {
                $title = Title::makeTitle( NS_FILE, $title->getDBkey() );
            }
            if ( !is_null( $arg ) ) {
                $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( 'rawsuffix', $arg ) ) {
            $func = [ $parser->getFunctionLang(), 'parseFormattedNumber' ];
        } elseif ( self::matchAgainstMagicword( 'nocommafysuffix', $arg ) ) {
            $func = [ $parser->getFunctionLang(), 'formatNumNoSeparators' ];
        } else {
            $func = [ $parser->getFunctionLang(), 'formatNum' ];
        }
        return $parser->markerSkipCallback( $num, $func );
    }

    public static function grammar( $parser, $case = '', $word = '' ) {
        $word = $parser->killMarkers( $word );
        return $parser->getFunctionLang()->convertGrammar( $word, $case );
    }

    public static function gender( $parser, $username ) {
        $forms = array_slice( func_get_args(), 2 );

        // Some shortcuts to avoid loading user data unnecessarily
        if ( count( $forms ) === 0 ) {
            return '';
        } elseif ( count( $forms ) === 1 ) {
            return $forms[0];
        }

        $username = trim( $username );

        // default
        $gender = User::getDefaultOption( 'gender' );

        // allow prefix.
        $title = Title::newFromText( $username );

        if ( $title && $title->getNamespace() == NS_USER ) {
            $username = $title->getText();
        }

        // check parameter, or use the ParserOptions if in interface message
        $user = User::newFromName( $username );
        if ( $user ) {
            $gender = GenderCache::singleton()->getGenderOf( $user, __METHOD__ );
        } elseif ( $username === '' && $parser->getOptions()->getInterfaceMessage() ) {
            $gender = GenderCache::singleton()->getGenderOf( $parser->getOptions()->getUser(), __METHOD__ );
        }
        $ret = $parser->getFunctionLang()->gender( $gender, $forms );
        return $ret;
    }

    public static function plural( $parser, $text = '' ) {
        $forms = array_slice( func_get_args(), 2 );
        $text = $parser->getFunctionLang()->parseFormattedNumber( $text );
        settype( $text, ctype_digit( $text ) ? 'int' : 'float' );
        return $parser->getFunctionLang()->convertPlural( $text, $forms );
    }

    public static function bidi( $parser, $text = '' ) {
        return $parser->getFunctionLang()->embedBidi( $text );
    }

    public static function displaytitle( $parser, $text = '', $uarg = '' ) {
        global $wgRestrictDisplayTitle;

        static $magicWords = null;
        if ( is_null( $magicWords ) ) {
            $magicWords = new MagicWordArray( [ '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 );

        // 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 ( $wgRestrictDisplayTitle ) {
            $htmlTagsCallback = function ( &$params ) {
                $decoded = Sanitizer::decodeTagAttributes( $params );

                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 */';
                    }
                }

                $params = Sanitizer::safeEncodeTagAttributes( $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::normalizeCharReferences( Sanitizer::removeHTMLtags(
            $text,
            $htmlTagsCallback,
            [],
            [],
            $bad
        ) );
        $title = Title::newFromText( Sanitizer::stripAllTags( $text ) );

        if ( !$wgRestrictDisplayTitle ||
            ( $title instanceof Title
            && !$title->hasFragment()
            && $title->equals( $parser->mTitle ) )
        ) {
            $old = $parser->mOutput->getProperty( 'displaytitle' );
            if ( $old === false || $arg !== 'displaytitle_noreplace' ) {
                $parser->mOutput->setDisplayTitle( $text );
            }
            if ( $old !== false && $old !== $text && !$arg ) {
                $converter = $parser->getConverterLanguage()->getConverter();
                return '<span class="error">' .
                    wfMessage( 'duplicate-displaytitle',
                        // Message should be parsed, but these params should only be escaped.
                        $converter->markNoConversion( wfEscapeWikiText( $old ) ),
                        $converter->markNoConversion( wfEscapeWikiText( $text ) )
                    )->inContentLanguage()->text() .
                    '</span>';
            }
        }

        return '';
    }

    private static function matchAgainstMagicword( $magicword, $value ) {
        $value = trim( strval( $value ) );
        if ( $value === '' ) {
            return false;
        }
        $mwObject = MagicWord::get( $magicword );
        return $mwObject->matchStartToEnd( $value );
    }

    public static function formatRaw( $num, $raw ) {
        if ( self::matchAgainstMagicword( 'rawsuffix', $raw ) ) {
            return $num;
        } else {
            global $wgContLang;
            return $wgContLang->formatNum( $num );
        }
    }
    public static function numberofpages( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::pages(), $raw );
    }
    public static function numberofusers( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::users(), $raw );
    }
    public static function numberofactiveusers( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::activeUsers(), $raw );
    }
    public static function numberofarticles( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::articles(), $raw );
    }
    public static function numberoffiles( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::images(), $raw );
    }
    public static function numberofadmins( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::numberingroup( 'sysop' ), $raw );
    }
    public static function numberofedits( $parser, $raw = null ) {
        return self::formatRaw( SiteStats::edits(), $raw );
    }
    public static function pagesinnamespace( $parser, $namespace = 0, $raw = null ) {
        return self::formatRaw( SiteStats::pagesInNs( intval( $namespace ) ), $raw );
    }
    public static function numberingroup( $parser, $name = '', $raw = null ) {
        return self::formatRaw( SiteStats::numberingroup( strtolower( $name ) ), $raw );
    }

    public static function mwnamespace( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return str_replace( '_', ' ', $t->getNsText() );
    }
    public static function namespacee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfUrlencode( $t->getNsText() );
    }
    public static function namespacenumber( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return $t->getNamespace();
    }
    public static function talkspace( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) || !$t->canTalk() ) {
            return '';
        }
        return str_replace( '_', ' ', $t->getTalkNsText() );
    }
    public static function talkspacee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) || !$t->canTalk() ) {
            return '';
        }
        return wfUrlencode( $t->getTalkNsText() );
    }
    public static function subjectspace( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return str_replace( '_', ' ', $t->getSubjectNsText() );
    }
    public static function subjectspacee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfUrlencode( $t->getSubjectNsText() );
    }

    public static function pagename( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( $t->getText() );
    }
    public static function pagenamee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( $t->getPartialURL() );
    }
    public static function fullpagename( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) || !$t->canTalk() ) {
            return '';
        }
        return wfEscapeWikiText( $t->getPrefixedText() );
    }
    public static function fullpagenamee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) || !$t->canTalk() ) {
            return '';
        }
        return wfEscapeWikiText( $t->getPrefixedURL() );
    }
    public static function subpagename( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( $t->getSubpageText() );
    }
    public static function subpagenamee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( $t->getSubpageUrlForm() );
    }
    public static function rootpagename( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( $t->getRootText() );
    }
    public static function rootpagenamee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( wfUrlencode( str_replace( ' ', '_', $t->getRootText() ) ) );
    }
    public static function basepagename( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( $t->getBaseText() );
    }
    public static function basepagenamee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( wfUrlencode( str_replace( ' ', '_', $t->getBaseText() ) ) );
    }
    public static function talkpagename( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) || !$t->canTalk() ) {
            return '';
        }
        return wfEscapeWikiText( $t->getTalkPage()->getPrefixedText() );
    }
    public static function talkpagenamee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) || !$t->canTalk() ) {
            return '';
        }
        return wfEscapeWikiText( $t->getTalkPage()->getPrefixedURL() );
    }
    public static function subjectpagename( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( $t->getSubjectPage()->getPrefixedText() );
    }
    public static function subjectpagenamee( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        return wfEscapeWikiText( $t->getSubjectPage()->getPrefixedURL() );
    }

    public static function pagesincategory( $parser, $name = '', $arg1 = null, $arg2 = null ) {
        global $wgContLang;
        static $magicWords = null;
        if ( is_null( $magicWords ) ) {
            $magicWords = new MagicWordArray( [
                'pagesincategory_all',
                'pagesincategory_pages',
                'pagesincategory_subcats',
                'pagesincategory_files'
            ] );
        }
        static $cache = [];

        // split the given option to its variable
        if ( self::matchAgainstMagicword( '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 );
        }
        $wgContLang->findVariantLink( $name, $title, true );

        // Normalize name for cache
        $name = $title->getDBkey();

        if ( !isset( $cache[$name] ) ) {
            $category = Category::newFromTitle( $title );

            $allCount = $subcatCount = $fileCount = $pagesCount = 0;
            if ( $parser->incrementExpensiveFunctionCount() ) {
                // $allCount is the total number of cat members,
                // not the count of how many members are normal pages.
                $allCount = (int)$category->getPageCount();
                $subcatCount = (int)$category->getSubcatCount();
                $fileCount = (int)$category->getFileCount();
                $pagesCount = $allCount - $subcatCount - $fileCount;
            }
            $cache[$name]['pagesincategory_all'] = $allCount;
            $cache[$name]['pagesincategory_pages'] = $pagesCount;
            $cache[$name]['pagesincategory_subcats'] = $subcatCount;
            $cache[$name]['pagesincategory_files'] = $fileCount;
        }

        $count = $cache[$name][$type];
        return self::formatRaw( $count, $raw );
    }

    public static function pagesize( $parser, $page = '', $raw = null ) {
        $title = Title::newFromText( $page );

        if ( !is_object( $title ) ) {
            return self::formatRaw( 0, $raw );
        }

        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $title );
        $length = $rev ? $rev->getSize() : 0;
        return self::formatRaw( $length, $raw );
    }

    public static function protectionlevel( $parser, $type = '', $title = '' ) {
        $titleObject = Title::newFromText( $title );
        if ( !( $titleObject instanceof Title ) ) {
            $titleObject = $parser->mTitle;
        }
        if ( $titleObject->areRestrictionsLoaded() || $parser->incrementExpensiveFunctionCount() ) {
            $restrictions = $titleObject->getRestrictions( strtolower( $type ) );
            # Title::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 );
        if ( !( $titleObject instanceof Title ) ) {
            $titleObject = $parser->mTitle;
        }
        if ( $titleObject->areRestrictionsLoaded() || $parser->incrementExpensiveFunctionCount() ) {
            $expiry = $titleObject->getRestrictionExpiry( strtolower( $type ) );
            // getRestrictionExpiry() returns false on invalid type; trying to
            // match protectionlevel() function that returns empty string instead
            if ( $expiry === false ) {
                $expiry = '';
            }
            return $expiry;
        }
        return '';
    }

    public static function language( $parser, $code = '', $inLanguage = '' ) {
        $code = strtolower( $code );
        $inLanguage = strtolower( $inLanguage );
        $lang = Language::fetchLanguageName( $code, $inLanguage );
        return $lang !== '' ? $lang : wfBCP47( $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( $length, 500 ) - mb_strlen( $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 );
        return (string)substr( $parser->guessSectionNameFromWikiText( $text ), 1 );
    }

    public static function special( $parser, $text ) {
        list( $page, $subpage ) = SpecialPageFactory::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 ( is_null( $magicWords ) ) {
            $magicWords = new MagicWordArray( [ 'defaultsort_noerror', 'defaultsort_noreplace' ] );
        }
        $arg = $magicWords->matchStartToEnd( $uarg );

        $text = trim( $text );
        if ( strlen( $text ) == 0 ) {
            return '';
        }
        $old = $parser->getCustomDefaultSort();
        if ( $old === false || $arg !== 'defaultsort_noreplace' ) {
            $parser->setDefaultSort( $text );
        }

        if ( $old === false || $old == $text || $arg ) {
            return '';
        } else {
            $converter = $parser->getConverterLanguage()->getConverter();
            return '<span class="error">' .
                wfMessage( 'duplicate-defaultsort',
                    // Message should be parsed, but these params should only be escaped.
                    $converter->markNoConversion( wfEscapeWikiText( $old ) ),
                    $converter->markNoConversion( wfEscapeWikiText( $text ) )
                )->inContentLanguage()->text() .
                '</span>';
        }
    }

    public static function filepath( $parser, $name = '', $argA = '', $argB = '' ) {
        $file = wfFindFile( $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 ) ) ) );

        if ( count( $args ) ) {
            $inner = $frame->expand( array_shift( $args ) );
        } 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 = isset( $m[1] ) ? $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 ) . '"';
            }
            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 = null ) {
        if ( is_null( $title ) ) {
            return null;
        }

        // Use the revision from the parser itself, when param is the current page
        // and the revision is the current one
        if ( $title->equals( $parser->getTitle() ) ) {
            $parserRev = $parser->getRevisionObject();
            if ( $parserRev && $parserRev->isCurrent() ) {
                // force reparse after edit with vary-revision flag
                $parser->getOutput()->setFlag( 'vary-revision' );
                wfDebug( __METHOD__ . ": use current revision from parser, setting vary-revision...\n" );
                return $parserRev;
            }
        }

        // Normalize name for cache
        $page = $title->getPrefixedDBkey();

        if ( !( $parser->currentRevisionCache && $parser->currentRevisionCache->has( $page ) )
            && !$parser->incrementExpensiveFunctionCount() ) {
            return null;
        }
        $rev = $parser->fetchCurrentRevisionOfTitle( $title );
        $pageID = $rev ? $rev->getPage() : 0;
        $revID = $rev ? $rev->getId() : 0;

        // Register dependency in templatelinks
        $parser->getOutput()->addTemplate( $title, $pageID, $revID );

        return $rev;
    }

    public static function pageid( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // Use title from parser to have correct pageid after edit
        if ( $t->equals( $parser->getTitle() ) ) {
            $t = $parser->getTitle();
            return $t->getArticleID();
        }

        // These can't have ids
        if ( !$t->canExist() || $t->isExternal() ) {
            return 0;
        }

        // Check the link cache, maybe something already looked it up.
        $linkCache = LinkCache::singleton();
        $pdbk = $t->getPrefixedDBkey();
        $id = $linkCache->getGoodLinkID( $pdbk );
        if ( $id != 0 ) {
            $parser->mOutput->addLink( $t, $id );
            return $id;
        }
        if ( $linkCache->isBadLink( $pdbk ) ) {
            $parser->mOutput->addLink( $t, 0 );
            return $id;
        }

        // We need to load it from the DB, so mark expensive
        if ( $parser->incrementExpensiveFunctionCount() ) {
            $id = $t->getArticleID();
            $parser->mOutput->addLink( $t, $id );
            return $id;
        }
        return null;
    }

    public static function revisionid( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $t );
        return $rev ? $rev->getId() : '';
    }

    public static function revisionday( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $t );
        return $rev ? MWTimestamp::getLocalInstance( $rev->getTimestamp() )->format( 'j' ) : '';
    }

    public static function revisionday2( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $t );
        return $rev ? MWTimestamp::getLocalInstance( $rev->getTimestamp() )->format( 'd' ) : '';
    }

    public static function revisionmonth( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $t );
        return $rev ? MWTimestamp::getLocalInstance( $rev->getTimestamp() )->format( 'm' ) : '';
    }

    public static function revisionmonth1( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $t );
        return $rev ? MWTimestamp::getLocalInstance( $rev->getTimestamp() )->format( 'n' ) : '';
    }

    public static function revisionyear( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $t );
        return $rev ? MWTimestamp::getLocalInstance( $rev->getTimestamp() )->format( 'Y' ) : '';
    }

    public static function revisiontimestamp( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $t );
        return $rev ? MWTimestamp::getLocalInstance( $rev->getTimestamp() )->format( 'YmdHis' ) : '';
    }

    public static function revisionuser( $parser, $title = null ) {
        $t = Title::newFromText( $title );
        if ( is_null( $t ) ) {
            return '';
        }
        // fetch revision from cache/database and return the value
        $rev = self::getCachedRevisionObject( $parser, $t );
        return $rev ? $rev->getUserText() : '';
    }

    public static function cascadingsources( $parser, $title = '' ) {
        $titleObject = Title::newFromText( $title );
        if ( !( $titleObject instanceof Title ) ) {
            $titleObject = $parser->mTitle;
        }
        if ( $titleObject->areCascadeProtectionSourcesLoaded()
            || $parser->incrementExpensiveFunctionCount()
        ) {
            $names = [];
            $sources = $titleObject->getCascadeProtectionSources();
            foreach ( $sources[0] as $sourceTitle ) {
                $names[] = $sourceTitle->getPrefixedText();
            }
            return implode( $names, '|' );
        }
        return '';
    }

}