wikimedia/mediawiki-core

<?php
/**
 * API for MediaWiki 1.17+
 *
 * Copyright © 2011 Sam Reed
 * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
 *
 * 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
 */

/**
 * This gives links pointing to the given interwiki
 * @ingroup API
 */
class ApiQueryLangBacklinks extends ApiQueryGeneratorBase {

    /**
     * @param ApiQuery $query
     * @param string $moduleName
     */
    public function __construct( ApiQuery $query, $moduleName ) {
        parent::__construct( $query, $moduleName, 'lbl' );
    }

    public function execute() {
        $this->run();
    }

    public function executeGenerator( $resultPageSet ) {
        $this->run( $resultPageSet );
    }

    /**
     * @param ApiPageSet|null $resultPageSet
     * @return void
     */
    public function run( $resultPageSet = null ) {
        $params = $this->extractRequestParams();

        if ( isset( $params['title'] ) && !isset( $params['lang'] ) ) {
            $this->dieWithError(
                [
                    'apierror-invalidparammix-mustusewith',
                    $this->encodeParamName( 'title' ),
                    $this->encodeParamName( 'lang' )
                ],
                'nolang'
            );
        }

        if ( $params['continue'] !== null ) {
            $cont = explode( '|', $params['continue'] );
            $this->dieContinueUsageIf( count( $cont ) != 3 );

            $db = $this->getDB();
            $op = $params['dir'] == 'descending' ? '<' : '>';
            $prefix = $db->addQuotes( $cont[0] );
            $title = $db->addQuotes( $cont[1] );
            $from = (int)$cont[2];
            $this->addWhere(
                "ll_lang $op $prefix OR " .
                "(ll_lang = $prefix AND " .
                "(ll_title $op $title OR " .
                "(ll_title = $title AND " .
                "ll_from $op= $from)))"
            );
        }

        $prop = array_flip( $params['prop'] );
        $lllang = isset( $prop['lllang'] );
        $lltitle = isset( $prop['lltitle'] );

        $this->addTables( [ 'langlinks', 'page' ] );
        $this->addWhere( 'll_from = page_id' );

        $this->addFields( [ 'page_id', 'page_title', 'page_namespace', 'page_is_redirect',
            'll_from', 'll_lang', 'll_title' ] );

        $sort = ( $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' . $sort );
            } else {
                $this->addOption( 'ORDER BY', [
                    'll_title' . $sort,
                    'll_from' . $sort
                ] );
            }
        } else {
            $this->addOption( 'ORDER BY', [
                'll_lang' . $sort,
                'll_title' . $sort,
                'll_from' . $sort
            ] );
        }

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

        $res = $this->select( __METHOD__ );

        $pages = [];

        $count = 0;
        $result = $this->getResult();

        if ( $resultPageSet === null ) {
            $this->executeGenderCacheFromResultWrapper( $res, __METHOD__ );
        }

        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... Continue string
                // preserved in case the redirect query doesn't pass the limit.
                $this->setContinueEnumParameter(
                    'continue',
                    "{$row->ll_lang}|{$row->ll_title}|{$row->ll_from}"
                );
                break;
            }

            if ( $resultPageSet !== null ) {
                $pages[] = Title::newFromRow( $row );
            } else {
                $entry = [ 'pageid' => (int)$row->page_id ];

                $title = Title::makeTitle( $row->page_namespace, $row->page_title );
                ApiQueryBase::addTitleInfo( $entry, $title );

                if ( $row->page_is_redirect ) {
                    $entry['redirect'] = true;
                }

                if ( $lllang ) {
                    $entry['lllang'] = $row->ll_lang;
                }

                if ( $lltitle ) {
                    $entry['lltitle'] = $row->ll_title;
                }

                $fit = $result->addValue( [ 'query', $this->getModuleName() ], null, $entry );
                if ( !$fit ) {
                    $this->setContinueEnumParameter(
                        'continue',
                        "{$row->ll_lang}|{$row->ll_title}|{$row->ll_from}"
                    );
                    break;
                }
            }
        }

        if ( $resultPageSet === null ) {
            $result->addIndexedTagName( [ 'query', $this->getModuleName() ], 'll' );
        } else {
            $resultPageSet->populateFromTitles( $pages );
        }
    }

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

    public function getAllowedParams() {
        return [
            'lang' => null,
            'title' => null,
            'continue' => [
                ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
            ],
            'limit' => [
                ApiBase::PARAM_DFLT => 10,
                ApiBase::PARAM_TYPE => 'limit',
                ApiBase::PARAM_MIN => 1,
                ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
                ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
            ],
            'prop' => [
                ApiBase::PARAM_ISMULTI => true,
                ApiBase::PARAM_DFLT => '',
                ApiBase::PARAM_TYPE => [
                    'lllang',
                    'lltitle',
                ],
                ApiBase::PARAM_HELP_MSG_PER_VALUE => [],
            ],
            'dir' => [
                ApiBase::PARAM_DFLT => 'ascending',
                ApiBase::PARAM_TYPE => [
                    'ascending',
                    'descending'
                ]
            ],
        ];
    }

    protected function getExamplesMessages() {
        return [
            'action=query&list=langbacklinks&lbltitle=Test&lbllang=fr'
                => 'apihelp-query+langbacklinks-example-simple',
            'action=query&generator=langbacklinks&glbltitle=Test&glbllang=fr&prop=info'
                => 'apihelp-query+langbacklinks-example-generator',
        ];
    }

    public function getHelpUrls() {
        return 'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Langbacklinks';
    }
}