ApiQueryExternalLinks.php

Go to the documentation of this file.

<?php
class ApiQueryExternalLinks extends ApiQueryBase {

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

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

        $params = $this->extractRequestParams();

        $query = $params['query'];
        $protocol = ApiQueryExtLinksUsage::getProtocolPrefix( $params['protocol'] );

        $this->addFields( array(
            'el_from',
            'el_to'
        ) );

        $this->addTables( 'externallinks' );
        $this->addWhereFld( 'el_from', array_keys( $this->getPageSet()->getGoodTitles() ) );

        $whereQuery = $this->prepareUrlQuerySearchString( $query, $protocol );

        if ( $whereQuery !== null ) {
            $this->addWhere( $whereQuery );
        }

        // Don't order by el_from if it's constant in the WHERE clause
        if ( count( $this->getPageSet()->getGoodTitles() ) != 1 ) {
            $this->addOption( 'ORDER BY', 'el_from' );
        }

        // If we're querying all protocols, use DISTINCT to avoid repeating protocol-relative links twice
        if ( $protocol === null ) {
            $this->addOption( 'DISTINCT' );
        }

        $this->addOption( 'LIMIT', $params['limit'] + 1 );
        $offset = isset( $params['offset'] ) ? $params['offset'] : 0;
        if ( $offset ) {
            $this->addOption( 'OFFSET', $params['offset'] );
        }

        $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( 'offset', $offset + $params['limit'] );
                break;
            }
            $entry = array();
            $to = $row->el_to;
            // expand protocol-relative urls
            if ( $params['expandurl'] ) {
                $to = wfExpandUrl( $to, PROTO_CANONICAL );
            }
            ApiResult::setContent( $entry, $to );
            $fit = $this->addPageSubItem( $row->el_from, $entry );
            if ( !$fit ) {
                $this->setContinueEnumParameter( 'offset', $offset + $count - 1 );
                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
            ),
            'offset' => array(
                ApiBase::PARAM_TYPE => 'integer'
            ),
            'protocol' => array(
                ApiBase::PARAM_TYPE => ApiQueryExtLinksUsage::prepareProtocols(),
                ApiBase::PARAM_DFLT => '',
            ),
            'query' => null,
            'expandurl' => false,
        );
    }

    public function getParamDescription() {
        $p = $this->getModulePrefix();
        return array(
            'limit' => 'How many links to return',
            'offset' => 'When more results are available, use this to continue',
            'protocol' => array(
                "Protocol of the URL. If empty and {$p}query set, the protocol is http.",
                "Leave both this and {$p}query empty to list all external links"
            ),
            'query' => 'Search string without protocol. Useful for checking whether a certain page contains a certain external url',
            'expandurl' => 'Expand protocol-relative URLs with the canonical protocol',
        );
    }

    public function getResultProperties() {
        return array(
            '' => array(
                '*' => 'string'
            )
        );
    }

    public function getDescription() {
        return 'Returns all external URLs (not interwikis) from the given page(s)';
    }

    public function getPossibleErrors() {
        return array_merge( parent::getPossibleErrors(), array(
            array( 'code' => 'bad_query', 'info' => 'Invalid query' ),
        ) );
    }

    public function getExamples() {
        return array(
            'api.php?action=query&prop=extlinks&titles=Main%20Page' => 'Get a list of external links on the [[Main Page]]',
        );
    }

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