ApiHelp.php

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<?php
use MediaWiki\ExtensionInfo;
use MediaWiki\Html\Html;
use MediaWiki\Html\HtmlHelper;
use MediaWiki\Linker\Linker;
use MediaWiki\MainConfigNames;
use MediaWiki\MediaWikiServices;
use MediaWiki\Title\Title;
use Wikimedia\ParamValidator\ParamValidator;
use Wikimedia\Parsoid\Core\TOCData;
use Wikimedia\RemexHtml\Serializer\SerializerNode;
 
class ApiHelp extends ApiBase {
    private $skinFactory;
 
    public function __construct(
        ApiMain $main,
        $action,
        SkinFactory $skinFactory
    ) {
        parent::__construct( $main, $action );
        $this->skinFactory = $skinFactory;
    }
 
    public function execute() {
        $params = $this->extractRequestParams();
        $modules = [];
 
        foreach ( $params['modules'] as $path ) {
            $modules[] = $this->getModuleFromPath( $path );
        }
 
        // Get the help
        $context = new DerivativeContext( $this->getMain()->getContext() );
        $context->setSkin( $this->skinFactory->makeSkin( 'apioutput' ) );
        $context->setLanguage( $this->getMain()->getLanguage() );
        $context->setTitle( SpecialPage::getTitleFor( 'ApiHelp' ) );
        $out = new OutputPage( $context );
        $out->setRobotPolicy( 'noindex,nofollow' );
        $out->setCopyrightUrl( 'https://www.mediawiki.org/wiki/Special:MyLanguage/Copyright' );
        $out->disallowUserJs();
        $context->setOutput( $out );
 
        self::getHelp( $context, $modules, $params );
 
        // Grab the output from the skin
        ob_start();
        $context->getOutput()->output();
        $html = ob_get_clean();
 
        $result = $this->getResult();
        if ( $params['wrap'] ) {
            $data = [
                'mime' => 'text/html',
                'filename' => 'api-help.html',
                'help' => $html,
            ];
            ApiResult::setSubelementsList( $data, 'help' );
            $result->addValue( null, $this->getModuleName(), $data );
        } else {
            // Show any errors at the top of the HTML
            $transform = [
                'Types' => [ 'AssocAsObject' => true ],
                'Strip' => 'all',
            ];
            $errors = array_filter( [
                'errors' => $this->getResult()->getResultData( [ 'errors' ], $transform ),
                'warnings' => $this->getResult()->getResultData( [ 'warnings' ], $transform ),
            ] );
            if ( $errors ) {
                $json = FormatJson::encode( $errors, true, FormatJson::UTF8_OK );
                // Escape any "--", some parsers might interpret that as end-of-comment.
                // The above already escaped any "<" and ">".
                $json = str_replace( '--', '-\u002D', $json );
                $html = "<!-- API warnings and errors:\n$json\n-->\n$html";
            }
 
            $result->reset();
            $result->addValue( null, 'text', $html, ApiResult::NO_SIZE_CHECK );
            $result->addValue( null, 'mime', 'text/html', ApiResult::NO_SIZE_CHECK );
            $result->addValue( null, 'filename', 'api-help.html', ApiResult::NO_SIZE_CHECK );
        }
    }
 
    public static function getHelp( IContextSource $context, $modules, array $options ) {
        if ( !is_array( $modules ) ) {
            $modules = [ $modules ];
        }
 
        $out = $context->getOutput();
        $out->addModuleStyles( [
            'mediawiki.hlist',
            'mediawiki.apipretty',
        ] );
        $out->setPageTitle( $context->msg( 'api-help-title' ) );
 
        $services = MediaWikiServices::getInstance();
        $cache = $services->getMainWANObjectCache();
        $cacheKey = null;
        if ( count( $modules ) == 1 && $modules[0] instanceof ApiMain &&
            $options['recursivesubmodules'] &&
            $context->getLanguage()->equals( $services->getContentLanguage() )
        ) {
            $cacheHelpTimeout = $context->getConfig()->get( MainConfigNames::APICacheHelpTimeout );
            if ( $cacheHelpTimeout > 0 ) {
                // Get help text from cache if present
                $cacheKey = $cache->makeKey( 'apihelp', $modules[0]->getModulePath(),
                    (int)!empty( $options['toc'] ),
                    str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) ) );
                $cached = $cache->get( $cacheKey );
                if ( $cached ) {
                    $out->addHTML( $cached );
                    return;
                }
            }
        }
        if ( $out->getHTML() !== '' ) {
            // Don't save to cache, there's someone else's content in the page
            // already
            $cacheKey = null;
        }
 
        $options['recursivesubmodules'] = !empty( $options['recursivesubmodules'] );
        $options['submodules'] = $options['recursivesubmodules'] || !empty( $options['submodules'] );
 
        // Prepend lead
        if ( empty( $options['nolead'] ) ) {
            $msg = $context->msg( 'api-help-lead' );
            if ( !$msg->isDisabled() ) {
                $out->addHTML( $msg->parseAsBlock() );
            }
        }
 
        $haveModules = [];
        $html = self::getHelpInternal( $context, $modules, $options, $haveModules );
        if ( !empty( $options['toc'] ) && $haveModules ) {
            $out->addHTML( Linker::generateTOC( TOCData::fromLegacy( $haveModules ), $context->getLanguage() ) );
        }
        $out->addHTML( $html );
 
        $helptitle = $options['helptitle'] ?? null;
        $html = self::fixHelpLinks( $out->getHTML(), $helptitle, $haveModules );
        $out->clearHTML();
        $out->addHTML( $html );
 
        if ( $cacheKey !== null ) {
            // @phan-suppress-next-line PhanPossiblyUndeclaredVariable $cacheHelpTimeout declared when $cacheKey is set
            $cache->set( $cacheKey, $out->getHTML(), $cacheHelpTimeout );
        }
    }
 
    public static function fixHelpLinks( $html, $helptitle = null, $localModules = [] ) {
        return HtmlHelper::modifyElements(
            $html,
            static function ( SerializerNode $node ): bool {
                return $node->name === 'a'
                    && isset( $node->attrs['href'] )
                    && !str_contains( $node->attrs['class'] ?? '', 'apihelp-linktrail' );
            },
            static function ( SerializerNode $node ) use ( $helptitle, $localModules ): SerializerNode {
                $href = $node->attrs['href'];
                // FIXME This can't be right to do this in a loop
                do {
                    $old = $href;
                    $href = rawurldecode( $href );
                } while ( $old !== $href );
                if ( preg_match( '!Special:ApiHelp/([^&/|#]+)((?:#.*)?)!', $href, $m ) ) {
                    if ( isset( $localModules[$m[1]] ) ) {
                        $href = $m[2] === '' ? '#' . $m[1] : $m[2];
                    } elseif ( $helptitle !== null ) {
                        $href = Title::newFromText( str_replace( '$1', $m[1], $helptitle ) . $m[2] )
                            ->getFullURL();
                    } else {
                        $href = wfAppendQuery( wfScript( 'api' ), [
                            'action' => 'help',
                            'modules' => $m[1],
                        ] ) . $m[2];
                    }
                    $node->attrs['href'] = $href;
                    unset( $node->attrs['title'] );
                }
 
                return $node;
            }
        );
    }
 
    private static function wrap( Message $msg, $class, $tag = 'span' ) {
        return Html::rawElement( $tag, [ 'class' => $class ],
            $msg->parse()
        );
    }
 
    private static function getHelpInternal( IContextSource $context, array $modules,
        array $options, &$haveModules
    ) {
        $out = '';
 
        $level = empty( $options['headerlevel'] ) ? 2 : $options['headerlevel'];
        if ( empty( $options['tocnumber'] ) ) {
            $tocnumber = [ 2 => 0 ];
        } else {
            $tocnumber = &$options['tocnumber'];
        }
 
        foreach ( $modules as $module ) {
            $paramValidator = $module->getMain()->getParamValidator();
            $tocnumber[$level]++;
            $path = $module->getModulePath();
            $module->setContext( $context );
            $help = [
                'header' => '',
                'flags' => '',
                'description' => '',
                'help-urls' => '',
                'parameters' => '',
                'examples' => '',
                'submodules' => '',
            ];
 
            if ( empty( $options['noheader'] ) || !empty( $options['toc'] ) ) {
                $anchor = $path;
                $i = 1;
                while ( isset( $haveModules[$anchor] ) ) {
                    $anchor = $path . '|' . ++$i;
                }
 
                if ( $module->isMain() ) {
                    $headerContent = $context->msg( 'api-help-main-header' )->parse();
                    $headerAttr = [
                        'class' => 'apihelp-header',
                    ];
                } else {
                    $name = $module->getModuleName();
                    $headerContent = htmlspecialchars(
                        $module->getParent()->getModuleManager()->getModuleGroup( $name ) . "=$name"
                    );
                    if ( $module->getModulePrefix() !== '' ) {
                        $headerContent .= ' ' .
                            $context->msg( 'parentheses', $module->getModulePrefix() )->parse();
                    }
                    // Module names are always in English and not localized,
                    // so English language and direction must be set explicitly,
                    // otherwise parentheses will get broken in RTL wikis
                    $headerAttr = [
                        'class' => [ 'apihelp-header', 'apihelp-module-name' ],
                        'dir' => 'ltr',
                        'lang' => 'en',
                    ];
                }
 
                $headerAttr['id'] = $anchor;
 
                // T326687: Maybe transition to using a SectionMetadata object?
                $haveModules[$anchor] = [
                    'toclevel' => count( $tocnumber ),
                    'level' => $level,
                    'anchor' => $anchor,
                    'line' => $headerContent,
                    'number' => implode( '.', $tocnumber ),
                    'index' => false,
                ];
                if ( empty( $options['noheader'] ) ) {
                    $help['header'] .= Html::rawElement(
                        'h' . min( 6, $level ),
                        $headerAttr,
                        $headerContent
                    );
                }
            } else {
                $haveModules[$path] = true;
            }
 
            $links = [];
            $any = false;
            for ( $m = $module; $m !== null; $m = $m->getParent() ) {
                $name = $m->getModuleName();
                if ( $name === 'main_int' ) {
                    $name = 'main';
                }
 
                if ( count( $modules ) === 1 && $m === $modules[0] &&
                    !( !empty( $options['submodules'] ) && $m->getModuleManager() )
                ) {
                    $link = Html::element( 'b', [ 'dir' => 'ltr', 'lang' => 'en' ], $name );
                } else {
                    $link = SpecialPage::getTitleFor( 'ApiHelp', $m->getModulePath() )->getLocalURL();
                    $link = Html::element( 'a',
                        [ 'href' => $link, 'class' => 'apihelp-linktrail', 'dir' => 'ltr', 'lang' => 'en' ],
                        $name
                    );
                    $any = true;
                }
                array_unshift( $links, $link );
            }
            if ( $any ) {
                $help['header'] .= self::wrap(
                    $context->msg( 'parentheses' )
                        ->rawParams( $context->getLanguage()->pipeList( $links ) ),
                    'apihelp-linktrail', 'div'
                );
            }
 
            $flags = $module->getHelpFlags();
            $help['flags'] .= Html::openElement( 'div',
                [ 'class' => [ 'apihelp-block', 'apihelp-flags' ] ] );
            $msg = $context->msg( 'api-help-flags' );
            if ( !$msg->isDisabled() ) {
                $help['flags'] .= self::wrap(
                    $msg->numParams( count( $flags ) ), 'apihelp-block-head', 'div'
                );
            }
            $help['flags'] .= Html::openElement( 'ul' );
            foreach ( $flags as $flag ) {
                $help['flags'] .= Html::rawElement( 'li', [],
                    // The follow classes are used here:
                    // * apihelp-flag-generator
                    // * apihelp-flag-internal
                    // * apihelp-flag-mustbeposted
                    // * apihelp-flag-readrights
                    // * apihelp-flag-writerights
                    self::wrap( $context->msg( "api-help-flag-$flag" ), "apihelp-flag-$flag" )
                );
            }
            $sourceInfo = $module->getModuleSourceInfo();
            if ( $sourceInfo ) {
                if ( isset( $sourceInfo['namemsg'] ) ) {
                    $extname = $context->msg( $sourceInfo['namemsg'] )->text();
                } else {
                    // Probably English, so wrap it.
                    $extname = Html::element( 'span', [ 'dir' => 'ltr', 'lang' => 'en' ], $sourceInfo['name'] );
                }
                $help['flags'] .= Html::rawElement( 'li', [],
                    self::wrap(
                        $context->msg( 'api-help-source', $extname, $sourceInfo['name'] ),
                        'apihelp-source'
                    )
                );
 
                $link = SpecialPage::getTitleFor( 'Version', 'License/' . $sourceInfo['name'] );
                if ( isset( $sourceInfo['license-name'] ) ) {
                    $msg = $context->msg( 'api-help-license', $link,
                        Html::element( 'span', [ 'dir' => 'ltr', 'lang' => 'en' ], $sourceInfo['license-name'] )
                    );
                } elseif ( ExtensionInfo::getLicenseFileNames( dirname( $sourceInfo['path'] ) ) ) {
                    $msg = $context->msg( 'api-help-license-noname', $link );
                } else {
                    $msg = $context->msg( 'api-help-license-unknown' );
                }
                $help['flags'] .= Html::rawElement( 'li', [],
                    self::wrap( $msg, 'apihelp-license' )
                );
            } else {
                $help['flags'] .= Html::rawElement( 'li', [],
                    self::wrap( $context->msg( 'api-help-source-unknown' ), 'apihelp-source' )
                );
                $help['flags'] .= Html::rawElement( 'li', [],
                    self::wrap( $context->msg( 'api-help-license-unknown' ), 'apihelp-license' )
                );
            }
            $help['flags'] .= Html::closeElement( 'ul' );
            $help['flags'] .= Html::closeElement( 'div' );
 
            foreach ( $module->getFinalDescription() as $msg ) {
                $msg->setContext( $context );
                $help['description'] .= $msg->parseAsBlock();
            }
 
            $urls = $module->getHelpUrls();
            if ( $urls ) {
                if ( !is_array( $urls ) ) {
                    $urls = [ $urls ];
                }
                $help['help-urls'] .= Html::openElement( 'div',
                    [ 'class' => [ 'apihelp-block', 'apihelp-help-urls' ] ]
                );
                $msg = $context->msg( 'api-help-help-urls' );
                if ( !$msg->isDisabled() ) {
                    $help['help-urls'] .= self::wrap(
                        $msg->numParams( count( $urls ) ), 'apihelp-block-head', 'div'
                    );
                }
                $help['help-urls'] .= Html::openElement( 'ul' );
                foreach ( $urls as $url ) {
                    $help['help-urls'] .= Html::rawElement( 'li', [],
                        Html::element( 'a', [ 'href' => $url, 'dir' => 'ltr' ], $url )
                    );
                }
                $help['help-urls'] .= Html::closeElement( 'ul' );
                $help['help-urls'] .= Html::closeElement( 'div' );
            }
 
            $params = $module->getFinalParams( ApiBase::GET_VALUES_FOR_HELP );
            $dynamicParams = $module->dynamicParameterDocumentation();
            $groups = [];
            if ( $params || $dynamicParams !== null ) {
                $help['parameters'] .= Html::openElement( 'div',
                    [ 'class' => [ 'apihelp-block', 'apihelp-parameters' ] ]
                );
                $msg = $context->msg( 'api-help-parameters' );
                if ( !$msg->isDisabled() ) {
                    $help['parameters'] .= self::wrap(
                        $msg->numParams( count( $params ) ), 'apihelp-block-head', 'div'
                    );
                    if ( !$module->isMain() ) {
                        // Add a note explaining that other parameters may exist.
                        $help['parameters'] .= self::wrap(
                            $context->msg( 'api-help-parameters-note' ), 'apihelp-block-header', 'div'
                        );
                    }
                }
                $help['parameters'] .= Html::openElement( 'dl' );
 
                $descriptions = $module->getFinalParamDescription();
 
                foreach ( $params as $name => $settings ) {
                    $settings = $paramValidator->normalizeSettings( $settings );
 
                    if ( $settings[ParamValidator::PARAM_TYPE] === 'submodule' ) {
                        $groups[] = $name;
                    }
 
                    $help['parameters'] .= Html::rawElement( 'dt', [],
                        Html::element( 'span', [ 'dir' => 'ltr', 'lang' => 'en' ], $module->encodeParamName( $name ) )
                    );
 
                    // Add description
                    $description = [];
                    if ( isset( $descriptions[$name] ) ) {
                        foreach ( $descriptions[$name] as $msg ) {
                            $msg->setContext( $context );
                            $description[] = $msg->parseAsBlock();
                        }
                    }
                    if ( !array_filter( $description ) ) {
                        $description = [ self::wrap(
                            $context->msg( 'api-help-param-no-description' ),
                            'apihelp-empty'
                        ) ];
                    }
 
                    // Add "deprecated" flag
                    if ( !empty( $settings[ParamValidator::PARAM_DEPRECATED] ) ) {
                        $help['parameters'] .= Html::openElement( 'dd',
                            [ 'class' => 'info' ] );
                        $help['parameters'] .= self::wrap(
                            $context->msg( 'api-help-param-deprecated' ),
                            'apihelp-deprecated', 'strong'
                        );
                        $help['parameters'] .= Html::closeElement( 'dd' );
                    }
 
                    if ( $description ) {
                        $description = implode( '', $description );
                        $description = preg_replace( '!\s*</([oud]l)>\s*<\1>\s*!', "\n", $description );
                        $help['parameters'] .= Html::rawElement( 'dd',
                            [ 'class' => 'description' ], $description );
                    }
 
                    // Add usage info
                    $info = [];
                    $paramHelp = $paramValidator->getHelpInfo( $module, $name, $settings, [] );
 
                    unset( $paramHelp[ParamValidator::PARAM_DEPRECATED] );
 
                    if ( isset( $paramHelp[ParamValidator::PARAM_REQUIRED] ) ) {
                        $paramHelp[ParamValidator::PARAM_REQUIRED]->setContext( $context );
                        $info[] = $paramHelp[ParamValidator::PARAM_REQUIRED];
                        unset( $paramHelp[ParamValidator::PARAM_REQUIRED] );
                    }
 
                    // Custom info?
                    if ( !empty( $settings[ApiBase::PARAM_HELP_MSG_INFO] ) ) {
                        foreach ( $settings[ApiBase::PARAM_HELP_MSG_INFO] as $i ) {
                            $tag = array_shift( $i );
                            $info[] = $context->msg( "apihelp-{$path}-paraminfo-{$tag}" )
                                ->numParams( count( $i ) )
                                ->params( $context->getLanguage()->commaList( $i ) )
                                ->params( $module->getModulePrefix() )
                                ->parse();
                        }
                    }
 
                    // Templated?
                    if ( !empty( $settings[ApiBase::PARAM_TEMPLATE_VARS] ) ) {
                        $vars = [];
                        $msg = 'api-help-param-templated-var-first';
                        foreach ( $settings[ApiBase::PARAM_TEMPLATE_VARS] as $k => $v ) {
                            $vars[] = $context->msg( $msg, $k, $module->encodeParamName( $v ) );
                            $msg = 'api-help-param-templated-var';
                        }
                        $info[] = $context->msg( 'api-help-param-templated' )
                            ->numParams( count( $vars ) )
                            ->params( Message::listParam( $vars ) )
                            ->parse();
                    }
 
                    // Type documentation
                    foreach ( $paramHelp as $m ) {
                        $m->setContext( $context );
                        $info[] = $m;
                    }
 
                    foreach ( $info as $i ) {
                        $help['parameters'] .= Html::rawElement( 'dd', [ 'class' => 'info' ], $i );
                    }
                }
 
                if ( $dynamicParams !== null ) {
                    $dynamicParams = ApiBase::makeMessage( $dynamicParams, $context, [
                        $module->getModulePrefix(),
                        $module->getModuleName(),
                        $module->getModulePath()
                    ] );
                    $help['parameters'] .= Html::element( 'dt', [], '*' );
                    $help['parameters'] .= Html::rawElement( 'dd',
                        [ 'class' => 'description' ], $dynamicParams->parse() );
                }
 
                $help['parameters'] .= Html::closeElement( 'dl' );
                $help['parameters'] .= Html::closeElement( 'div' );
            }
 
            $examples = $module->getExamplesMessages();
            if ( $examples ) {
                $help['examples'] .= Html::openElement( 'div',
                    [ 'class' => [ 'apihelp-block', 'apihelp-examples' ] ] );
                $msg = $context->msg( 'api-help-examples' );
                if ( !$msg->isDisabled() ) {
                    $help['examples'] .= self::wrap(
                        $msg->numParams( count( $examples ) ), 'apihelp-block-head', 'div'
                    );
                }
 
                $help['examples'] .= Html::openElement( 'dl' );
                foreach ( $examples as $qs => $msg ) {
                    $msg = ApiBase::makeMessage( $msg, $context, [
                        $module->getModulePrefix(),
                        $module->getModuleName(),
                        $module->getModulePath()
                    ] );
 
                    $link = wfAppendQuery( wfScript( 'api' ), $qs );
                    $sandbox = SpecialPage::getTitleFor( 'ApiSandbox' )->getLocalURL() . '#' . $qs;
                    $help['examples'] .= Html::rawElement( 'dt', [], $msg->parse() );
                    $help['examples'] .= Html::rawElement( 'dd', [],
                        Html::element( 'a', [
                            'href' => $link,
                            'dir' => 'ltr',
                            'rel' => 'nofollow',
                        ], "api.php?$qs" ) . ' ' .
                        Html::rawElement( 'a', [ 'href' => $sandbox ],
                            $context->msg( 'api-help-open-in-apisandbox' )->parse() )
                    );
                }
                $help['examples'] .= Html::closeElement( 'dl' );
                $help['examples'] .= Html::closeElement( 'div' );
            }
 
            $subtocnumber = $tocnumber;
            $subtocnumber[$level + 1] = 0;
            $suboptions = [
                'submodules' => $options['recursivesubmodules'],
                'headerlevel' => $level + 1,
                'tocnumber' => &$subtocnumber,
                'noheader' => false,
            ] + $options;
 
            // @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
            if ( $options['submodules'] && $module->getModuleManager() ) {
                $manager = $module->getModuleManager();
                $submodules = [];
                foreach ( $groups as $group ) {
                    $names = $manager->getNames( $group );
                    sort( $names );
                    foreach ( $names as $name ) {
                        $submodules[] = $manager->getModule( $name );
                    }
                }
                $help['submodules'] .= self::getHelpInternal(
                    $context,
                    $submodules,
                    $suboptions,
                    $haveModules
                );
            }
 
            $module->modifyHelp( $help, $suboptions, $haveModules );
 
            $module->getHookRunner()->onAPIHelpModifyOutput( $module, $help,
                $suboptions, $haveModules );
 
            $out .= implode( "\n", $help );
        }
 
        return $out;
    }
 
    public function shouldCheckMaxlag() {
        return false;
    }
 
    public function isReadMode() {
        return false;
    }
 
    public function getCustomPrinter() {
        $params = $this->extractRequestParams();
        if ( $params['wrap'] ) {
            return null;
        }
 
        $main = $this->getMain();
        $errorPrinter = $main->createPrinterByName( $main->getParameter( 'format' ) );
        return new ApiFormatRaw( $main, $errorPrinter );
    }
 
    public function getAllowedParams() {
        return [
            'modules' => [
                ParamValidator::PARAM_DEFAULT => 'main',
                ParamValidator::PARAM_ISMULTI => true,
            ],
            'submodules' => false,
            'recursivesubmodules' => false,
            'wrap' => false,
            'toc' => false,
        ];
    }
 
    protected function getExamplesMessages() {
        return [
            'action=help'
                => 'apihelp-help-example-main',
            'action=help&modules=query&submodules=1'
                => 'apihelp-help-example-submodules',
            'action=help&recursivesubmodules=1'
                => 'apihelp-help-example-recursive',
            'action=help&modules=help'
                => 'apihelp-help-example-help',
            'action=help&modules=query+info|query+categorymembers'
                => 'apihelp-help-example-query',
        ];
    }
 
    public function getHelpUrls() {
        return [
            'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Main_page',
            'https://www.mediawiki.org/wiki/Special:MyLanguage/API:FAQ',
            'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Quick_start_guide',
        ];
    }
}