ApiQueryLangLinks.php

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<?php
class ApiQueryLangLinks extends ApiQueryBase {

        public function __construct( $query, $moduleName ) {
                parent::__construct( $query, $moduleName, 'll' );
        }

        public function execute() {
                if ( $this->getPageSet()->getGoodTitleCount() == 0 ) {
                        return;
                }

                $params = $this->extractRequestParams();

                if ( isset( $params['title'] ) && !isset( $params['lang'] ) ) {
                        $this->dieUsageMsg( array( 'missingparam', 'lang' ) );
                }

                $this->addFields( array(
                        'll_from',
                        'll_lang',
                        'll_title'
                ) );

                $this->addTables( 'langlinks' );
                $this->addWhereFld( 'll_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
                if ( !is_null( $params['continue'] ) ) {
                        $cont = explode( '|', $params['continue'] );
                        if ( count( $cont ) != 2 ) {
                                $this->dieUsage( 'Invalid continue param. You should pass the ' .
                                        'original value returned by the previous query', '_badcontinue' );
                        }
                        $llfrom = intval( $cont[0] );
                        $lllang = $this->getDB()->strencode( $cont[1] );
                        $this->addWhere(
                                "ll_from > $llfrom OR " .
                                "(ll_from = $llfrom AND " .
                                "ll_lang >= '$lllang')"
                        );
                }

            $dir = ( $params['dir'] == 'descending' ? ' DESC' : '' );
            if ( isset( $params['lang'] ) ) {
                        $this->addWhereFld( 'll_lang', $params['lang'] );
                        if ( isset( $params['title'] ) ) {
                                $this->addWhereFld( 'll_title', $params['title'] );
                                $this->addOption( 'ORDER BY', 'll_from' . $dir );
                        } else {
                                $this->addOption( 'ORDER BY', array(
                                                        'll_title' . $dir,
                                                        'll_from' . $dir
                                ));
                        }
                } else {
                        // Don't order by ll_from if it's constant in the WHERE clause
                        if ( count( $this->getPageSet()->getGoodTitles() ) == 1 ) {
                                $this->addOption( 'ORDER BY', 'll_lang' . $dir );
                        } else {
                                $this->addOption( 'ORDER BY', array(
                                                        'll_from' . $dir,
                                                        'll_lang' . $dir
                                ));
                        }
                }

                $this->addOption( 'LIMIT', $params['limit'] + 1 );
                $res = $this->select( __METHOD__ );

                $count = 0;
                foreach ( $res as $row ) {
                        if ( ++$count > $params['limit'] ) {
                                // We've reached the one extra which shows that
                                // there are additional pages to be had. Stop here...
                                $this->setContinueEnumParameter( 'continue', "{$row->ll_from}|{$row->ll_lang}" );
                                break;
                        }
                        $entry = array( 'lang' => $row->ll_lang );
                        if ( $params['url'] ) {
                                $title = Title::newFromText( "{$row->ll_lang}:{$row->ll_title}" );
                                if ( $title ) {
                                        $entry['url'] = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
                                }
                        }
                        ApiResult::setContent( $entry, $row->ll_title );
                        $fit = $this->addPageSubItem( $row->ll_from, $entry );
                        if ( !$fit ) {
                                $this->setContinueEnumParameter( 'continue', "{$row->ll_from}|{$row->ll_lang}" );
                                break;
                        }
                }
        }

        public function getCacheMode( $params ) {
                return 'public';
        }

        public function getAllowedParams() {
                return array(
                        'limit' => array(
                                ApiBase::PARAM_DFLT => 10,
                                ApiBase::PARAM_TYPE => 'limit',
                                ApiBase::PARAM_MIN => 1,
                                ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
                                ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
                        ),
                        'continue' => null,
                        'url' => false,
                        'lang' => null,
                        'title' => null,
                        'dir' => array(
                                ApiBase::PARAM_DFLT => 'ascending',
                                ApiBase::PARAM_TYPE => array(
                                        'ascending',
                                        'descending'
                                )
                        ),
                );
        }

        public function getParamDescription() {
                return array(
                        'limit' => 'How many langlinks to return',
                        'continue' => 'When more results are available, use this to continue',
                        'url' => 'Whether to get the full URL',
                        'lang' => 'Language code',
                        'title' => "Link to search for. Must be used with {$this->getModulePrefix()}lang",
                        'dir' => 'The direction in which to list',
                );
        }

        public function getDescription() {
                return 'Returns all interlanguage links from the given page(s)';
        }

        public function getPossibleErrors() {
                return array_merge( parent::getPossibleErrors(), array(
                        array( 'missingparam', 'lang' ),
                        array( 'code' => '_badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
                ) );
        }

        public function getExamples() {
                return array(
                        'api.php?action=query&prop=langlinks&titles=Main%20Page&redirects=' => 'Get interlanguage links from the [[Main Page]]',
                );
        }

        public function getHelpUrls() {
                return 'https://www.mediawiki.org/wiki/API:Properties#langlinks_.2F_ll';
        }

        public function getVersion() {
                return __CLASS__ . ': $Id$';
        }
}