ApiQueryLangBacklinks.php

Go to the documentation of this file.

<?php
class ApiQueryLangBacklinks extends ApiQueryGeneratorBase {

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

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

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

    public function run( $resultPageSet = null ) {
        $params = $this->extractRequestParams();

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

        if ( !is_null( $params['continue'] ) ) {
            $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 = intval( $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( array( 'langlinks', 'page' ) );
        $this->addWhere( 'll_from = page_id' );

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

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

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

        $pages = array();

        $count = 0;
        $result = $this->getResult();
        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 ( !is_null( $resultPageSet ) ) {
                $pages[] = Title::newFromRow( $row );
            } else {
                $entry = array( 'pageid' => $row->page_id );

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

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

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

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

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

        if ( is_null( $resultPageSet ) ) {
            $result->setIndexedTagName_internal( array( 'query', $this->getModuleName() ), 'll' );
        } else {
            $resultPageSet->populateFromTitles( $pages );
        }
    }

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

    public function getAllowedParams() {
        return array(
            'lang' => null,
            'title' => null,
            'continue' => null,
            '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
            ),
            'prop' => array(
                ApiBase::PARAM_ISMULTI => true,
                ApiBase::PARAM_DFLT => '',
                ApiBase::PARAM_TYPE => array(
                    'lllang',
                    'lltitle',
                ),
            ),
            'dir' => array(
                ApiBase::PARAM_DFLT => 'ascending',
                ApiBase::PARAM_TYPE => array(
                    'ascending',
                    'descending'
                )
            ),
        );
    }

    public function getParamDescription() {
        return array(
            'lang' => 'Language for the language link',
            'title' => "Language link to search for. Must be used with {$this->getModulePrefix()}lang",
            'continue' => 'When more results are available, use this to continue',
            'prop' => array(
                'Which properties to get',
                ' lllang         - Adds the language code of the language link',
                ' lltitle        - Adds the title of the language link',
            ),
            'limit' => 'How many total pages to return',
            'dir' => 'The direction in which to list',
        );
    }

    public function getResultProperties() {
        return array(
            '' => array(
                'pageid' => 'integer',
                'ns' => 'namespace',
                'title' => 'string',
                'redirect' => 'boolean'
            ),
            'lllang' => array(
                'lllang' => 'string'
            ),
            'lltitle' => array(
                'lltitle' => 'string'
            )
        );
    }

    public function getDescription() {
        return array( 'Find all pages that link to the given language link.',
            'Can be used to find all links with a language code, or',
            'all links to a title (with a given language).',
            'Using neither parameter is effectively "All Language Links".',
            'Note that this may not consider language links added by extensions.',
        );
    }

    public function getPossibleErrors() {
        return array_merge( parent::getPossibleErrors(), array(
            array( 'missingparam', 'lang' ),
        ) );
    }

    public function getExamples() {
        return array(
            'api.php?action=query&list=langbacklinks&lbltitle=Test&lbllang=fr',
            'api.php?action=query&generator=langbacklinks&glbltitle=Test&glbllang=fr&prop=info'
        );
    }

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