Merge "Special:Upload should not crash on failing previews"

[mediawiki.git] / includes / parser / CoreParserFunctions.php

<?php
/**
 * Parser functions provided by MediaWiki core
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Parser
 */
use MediaWiki\MediaWikiServices;

/**
 * Various core parser functions, registered in Parser::firstCallInit()
 * @ingroup Parser
 */
class CoreParserFunctions {
        /**
         * @param Parser $parser
         * @return void
         */
        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
                        );
                }
        }

        /**
         * @param Parser $parser
         * @param string $part1
         * @return array
         */
        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 ];
                }
        }

        /**
         * @param Parser $parser
         * @param string $date
         * @param string $defaultPref
         *
         * @return string
         */
        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;
        }

        /**
         * urlencodes a string according to one of three patterns: (bug 22474)
         *
         * By default (for HTTP "query" strings), spaces are encoded as '+'.
         * Or to encode a value for the HTTP "path", spaces are encoded as '%20'.
         * For links to "wiki"s, or similar software, spaces are encoded as '_',
         *
         * @param Parser $parser
         * @param string $s The text to encode.
         * @param string $arg (optional): The type of encoding.
         * @return string
         */
        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 );
        }

        /**
         * @param Parser $parser
         * @param string $s
         * @return string
         */
        public static function lc( $parser, $s = '' ) {
                global $wgContLang;
                return $parser->markerSkipCallback( $s, [ $wgContLang, 'lc' ] );
        }

        /**
         * @param Parser $parser
         * @param string $s
         * @return string
         */
        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->inNamespace( 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 ];
                }
        }

        /**
         * @param Parser $parser
         * @param string $num
         * @param string $arg
         * @return string
         */
        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 );
        }

        /**
         * @param Parser $parser
         * @param string $case
         * @param string $word
         * @return string
         */
        public static function grammar( $parser, $case = '', $word = '' ) {
                $word = $parser->killMarkers( $word );
                return $parser->getFunctionLang()->convertGrammar( $word, $case );
        }

        /**
         * @param Parser $parser
         * @param string $username
         * @return string
         */
        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->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()->getUser(), __METHOD__ );
                }
                $ret = $parser->getFunctionLang()->gender( $gender, $forms );
                return $ret;
        }

        /**
         * @param Parser $parser
         * @param string $text
         * @return string
         */
        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 );
        }

        /**
         * @param Parser $parser
         * @param string $text
         * @return string
         */
        public static function bidi( $parser, $text = '' ) {
                return $parser->getFunctionLang()->embedBidi( $text );
        }

        /**
         * Override the title of the page when viewed, provided we've been given a
         * title which will normalise to the canonical title
         *
         * @param Parser $parser Parent parser
         * @param string $text Desired title text
         * @param string $uarg
         * @return string
         */
        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>';
                        } else {
                                return '';
                        }
                } else {
                        $converter = $parser->getConverterLanguage()->getConverter();
                        $parser->getOutput()->addWarning(
                                wfMessage( 'restricted-displaytitle',
                                        // Message should be parsed, but this param should only be escaped.
                                        $converter->markNoConversion( wfEscapeWikiText( $text ) )
                                )->text()
                        );
                        $parser->addTrackingCategory( 'restricted-displaytitle-ignored' );
                }
        }

        /**
         * Matches the given value against the value of given magic word
         *
         * @param string $magicword Magic word key
         * @param string $value Value to match
         * @return bool True on successful match
         */
        private static function matchAgainstMagicword( $magicword, $value ) {
                $value = trim( strval( $value ) );
                if ( $value === '' ) {
                        return false;
                }
                $mwObject = MagicWord::get( $magicword );
                return $mwObject->matchStartToEnd( $value );
        }

        /**
         * Formats a number according to a language.
         *
         * @param int|float $num
         * @param string $raw
         * @param Language|StubUserLang $language
         * @return string
         */
        public static function formatRaw( $num, $raw, $language ) {
                if ( self::matchAgainstMagicword( 'rawsuffix', $raw ) ) {
                        return $num;
                } else {
                        return $language->formatNum( $num );
                }
        }

        public static function numberofpages( $parser, $raw = null ) {
                return self::formatRaw( SiteStats::pages(), $raw, $parser->getFunctionLang() );
        }

        public static function numberofusers( $parser, $raw = null ) {
                return self::formatRaw( SiteStats::users(), $raw, $parser->getFunctionLang() );
        }
        public static function numberofactiveusers( $parser, $raw = null ) {
                return self::formatRaw( SiteStats::activeUsers(), $raw, $parser->getFunctionLang() );
        }

        public static function numberofarticles( $parser, $raw = null ) {
                return self::formatRaw( SiteStats::articles(), $raw, $parser->getFunctionLang() );
        }

        public static function numberoffiles( $parser, $raw = null ) {
                return self::formatRaw( SiteStats::images(), $raw, $parser->getFunctionLang() );
        }

        public static function numberofadmins( $parser, $raw = null ) {
                return self::formatRaw(
                        SiteStats::numberingroup( 'sysop' ),
                        $raw,
                        $parser->getFunctionLang()
                );
        }

        public static function numberofedits( $parser, $raw = null ) {
                return self::formatRaw( SiteStats::edits(), $raw, $parser->getFunctionLang() );
        }

        public static function pagesinnamespace( $parser, $namespace = 0, $raw = null ) {
                return self::formatRaw(
                        SiteStats::pagesInNs( intval( $namespace ) ),
                        $raw,
                        $parser->getFunctionLang()
                );
        }
        public static function numberingroup( $parser, $name = '', $raw = null ) {
                return self::formatRaw(
                        SiteStats::numberingroup( strtolower( $name ) ),
                        $raw,
                        $parser->getFunctionLang()
                );
        }

        /**
         * Given a title, return the namespace name that would be given by the
         * corresponding magic word
         * Note: function name changed to "mwnamespace" rather than "namespace"
         * to not break PHP 5.3
         * @param Parser $parser
         * @param string $title
         * @return mixed|string
         */
        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() );
        }

        /**
         * Functions to get and normalize pagenames, corresponding to the magic words
         * of the same names
         * @param Parser $parser
         * @param string $title
         * @return string
         */
        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() );
        }

        /**
         * Return the number of pages, files or subcats in the given category,
         * or 0 if it's nonexistent. This is an expensive parser function and
         * can't be called too many times per page.
         * @param Parser $parser
         * @param string $name
         * @param string $arg1
         * @param string $arg2
         * @return string
         */
        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, $parser->getFunctionLang() );
                }
                $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, $parser->getFunctionLang() );
        }

        /**
         * Return the size of the given page, or 0 if it's nonexistent.  This is an
         * expensive parser function and can't be called too many times per page.
         *
         * @param Parser $parser
         * @param string $page Name of page to check (Default: empty string)
         * @param string $raw Should number be human readable with commas or just number
         * @return string
         */
        public static function pagesize( $parser, $page = '', $raw = null ) {
                $title = Title::newFromText( $page );

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

                // fetch revision from cache/database and return the value
                $rev = self::getCachedRevisionObject( $parser, $title );
                $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->getFunctionLang() );
        }

        /**
         * Returns the requested protection level for the current page. This
         * is an expensive parser function and can't be called too many times
         * per page, unless the protection levels/expiries for the given title
         * have already been retrieved
         *
         * @param Parser $parser
         * @param string $type
         * @param string $title
         *
         * @return string
         */
        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 '';
        }

        /**
         * Returns the requested protection expiry for the current page. This
         * is an expensive parser function and can't be called too many times
         * per page, unless the protection levels/expiries for the given title
         * have already been retrieved
         *
         * @param Parser $parser
         * @param string $type
         * @param string $title
         *
         * @return string
         */
        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 '';
        }

        /**
         * Gives language names.
         * @param Parser $parser
         * @param string $code Language code (of which to get name)
         * @param string $inLanguage Language code (in which to get name)
         * @return string
         */
        public static function language( $parser, $code = '', $inLanguage = '' ) {
                $code = strtolower( $code );
                $inLanguage = strtolower( $inLanguage );
                $lang = Language::fetchLanguageName( $code, $inLanguage );
                return $lang !== '' ? $lang : wfBCP47( $code );
        }

        /**
         * Unicode-safe str_pad with the restriction that $length is forced to be <= 500
         * @param Parser $parser
         * @param string $string
         * @param int $length
         * @param string $padding
         * @param int $direction
         * @return string
         */
        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 );
        }

        /**
         * @param Parser $parser
         * @param string $text
         * @return string
         */
        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 ) ) );
        }

        /**
         * @param Parser $parser
         * @param string $text The sortkey to use
         * @param string $uarg Either "noreplace" or "noerror" (in en)
         *   both suppress errors, and noreplace does nothing if
         *   a default sortkey already exists.
         * @return string
         */
        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>';
                }
        }

        /**
         * Usage {{filepath|300}}, {{filepath|nowiki}}, {{filepath|nowiki|300}}
         * or {{filepath|300|nowiki}} or {{filepath|300px}}, {{filepath|200x300px}},
         * {{filepath|nowiki|200x300px}}, {{filepath|200x300px|nowiki}}.
         *
         * @param Parser $parser
         * @param string $name
         * @param string $argA
         * @param string $argB
         * @return array|string
         */
        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 '';
                }
        }

        /**
         * Parser function to extension tag adaptor
         * @param Parser $parser
         * @param PPFrame $frame
         * @param PPNode[] $args
         * @return string
         */
        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 );
        }

        /**
         * Fetched the current revision of the given title and return this.
         * Will increment the expensive function count and
         * add a template link to get the value refreshed on changes.
         * For a given title, which is equal to the current parser title,
         * the revision object from the parser is used, when that is the current one
         *
         * @param Parser $parser
         * @param Title $title
         * @return Revision
         * @since 1.23
         */
        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;
        }

        /**
         * Get the pageid of a specified page
         * @param Parser $parser
         * @param string $title Title to get the pageid from
         * @return int|null|string
         * @since 1.23
         */
        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;
        }

        /**
         * Get the id from the last revision of a specified page.
         * @param Parser $parser
         * @param string $title Title to get the id from
         * @return int|null|string
         * @since 1.23
         */
        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() : '';
        }

        /**
         * Get the day from the last revision of a specified page.
         * @param Parser $parser
         * @param string $title Title to get the day from
         * @return string
         * @since 1.23
         */
        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' ) : '';
        }

        /**
         * Get the day with leading zeros from the last revision of a specified page.
         * @param Parser $parser
         * @param string $title Title to get the day from
         * @return string
         * @since 1.23
         */
        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' ) : '';
        }

        /**
         * Get the month with leading zeros from the last revision of a specified page.
         * @param Parser $parser
         * @param string $title Title to get the month from
         * @return string
         * @since 1.23
         */
        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' ) : '';
        }

        /**
         * Get the month from the last revision of a specified page.
         * @param Parser $parser
         * @param string $title Title to get the month from
         * @return string
         * @since 1.23
         */
        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' ) : '';
        }

        /**
         * Get the year from the last revision of a specified page.
         * @param Parser $parser
         * @param string $title Title to get the year from
         * @return string
         * @since 1.23
         */
        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' ) : '';
        }

        /**
         * Get the timestamp from the last revision of a specified page.
         * @param Parser $parser
         * @param string $title Title to get the timestamp from
         * @return string
         * @since 1.23
         */
        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' ) : '';
        }

        /**
         * Get the user from the last revision of a specified page.
         * @param Parser $parser
         * @param string $title Title to get the user from
         * @return string
         * @since 1.23
         */
        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() : '';
        }

        /**
         * Returns the sources of any cascading protection acting on a specified page.
         * Pages will not return their own title unless they transclude themselves.
         * This is an expensive parser function and can't be called too many times per page,
         * unless cascading protection sources for the page have already been loaded.
         *
         * @param Parser $parser
         * @param string $title
         *
         * @return string
         * @since 1.23
         */
        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 '';
        }

}