Remove "related" searches

[mediawiki.git] / includes / api / ApiQuerySearch.php

<?php
/**
 *
 *
 * Created on July 30, 2007
 *
 * Copyright © 2007 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
 */

/**
 * Query module to perform full text search within wiki titles and content
 *
 * @ingroup API
 */
class ApiQuerySearch extends ApiQueryGeneratorBase {

        /**
         * When $wgSearchType is null, $wgSearchAlternatives[0] is null. Null isn't
         * a valid option for an array for PARAM_TYPE, so we'll use a fake name
         * that can't possibly be a class name and describes what the null behavior
         * does
         */
        const BACKEND_NULL_PARAM = 'database-backed';

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

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

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

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

                // Extract parameters
                $limit = $params['limit'];
                $query = $params['search'];
                $what = $params['what'];
                $interwiki = $params['interwiki'];
                $searchInfo = array_flip( $params['info'] );
                $prop = array_flip( $params['prop'] );

                // Create search engine instance and set options
                $search = isset( $params['backend'] ) && $params['backend'] != self::BACKEND_NULL_PARAM ?
                        SearchEngine::create( $params['backend'] ) : SearchEngine::create();
                $search->setLimitOffset( $limit + 1, $params['offset'] );
                $search->setNamespaces( $params['namespace'] );

                $query = $search->transformSearchTerm( $query );
                $query = $search->replacePrefixes( $query );

                // Perform the actual search
                if ( $what == 'text' ) {
                        $matches = $search->searchText( $query );
                } elseif ( $what == 'title' ) {
                        $matches = $search->searchTitle( $query );
                } elseif ( $what == 'nearmatch' ) {
                        $matches = SearchEngine::getNearMatchResultSet( $query );
                } else {
                        // We default to title searches; this is a terrible legacy
                        // of the way we initially set up the MySQL fulltext-based
                        // search engine with separate title and text fields.
                        // In the future, the default should be for a combined index.
                        $what = 'title';
                        $matches = $search->searchTitle( $query );

                        // Not all search engines support a separate title search,
                        // for instance the Lucene-based engine we use on Wikipedia.
                        // In this case, fall back to full-text search (which will
                        // include titles in it!)
                        if ( is_null( $matches ) ) {
                                $what = 'text';
                                $matches = $search->searchText( $query );
                        }
                }
                if ( is_null( $matches ) ) {
                        $this->dieUsage( "{$what} search is disabled", "search-{$what}-disabled" );
                } elseif ( $matches instanceof Status && !$matches->isGood() ) {
                        $this->dieUsage( $matches->getWikiText(), 'search-error' );
                }

                $apiResult = $this->getResult();
                // Add search meta data to result
                if ( isset( $searchInfo['totalhits'] ) ) {
                        $totalhits = $matches->getTotalHits();
                        if ( $totalhits !== null ) {
                                $apiResult->addValue( array( 'query', 'searchinfo' ),
                                        'totalhits', $totalhits );
                        }
                }
                if ( isset( $searchInfo['suggestion'] ) && $matches->hasSuggestion() ) {
                        $apiResult->addValue( array( 'query', 'searchinfo' ),
                                'suggestion', $matches->getSuggestionQuery() );
                }

                // Add the search results to the result
                $terms = $wgContLang->convertForSearchResult( $matches->termMatches() );
                $titles = array();
                $count = 0;
                $result = $matches->next();

                while ( $result ) {
                        if ( ++$count > $limit ) {
                                // We've reached the one extra which shows that there are
                                // additional items to be had. Stop here...
                                $this->setContinueEnumParameter( 'offset', $params['offset'] + $params['limit'] );
                                break;
                        }

                        // Silently skip broken and missing titles
                        if ( $result->isBrokenTitle() || $result->isMissingRevision() ) {
                                $result = $matches->next();
                                continue;
                        }

                        $title = $result->getTitle();
                        if ( is_null( $resultPageSet ) ) {
                                $vals = array();
                                ApiQueryBase::addTitleInfo( $vals, $title );

                                if ( isset( $prop['snippet'] ) ) {
                                        $vals['snippet'] = $result->getTextSnippet( $terms );
                                }
                                if ( isset( $prop['size'] ) ) {
                                        $vals['size'] = $result->getByteSize();
                                }
                                if ( isset( $prop['wordcount'] ) ) {
                                        $vals['wordcount'] = $result->getWordCount();
                                }
                                if ( isset( $prop['timestamp'] ) ) {
                                        $vals['timestamp'] = wfTimestamp( TS_ISO_8601, $result->getTimestamp() );
                                }
                                if ( isset( $prop['titlesnippet'] ) ) {
                                        $vals['titlesnippet'] = $result->getTitleSnippet( $terms );
                                }
                                if ( !is_null( $result->getRedirectTitle() ) ) {
                                        if ( isset( $prop['redirecttitle'] ) ) {
                                                $vals['redirecttitle'] = $result->getRedirectTitle();
                                        }
                                        if ( isset( $prop['redirectsnippet'] ) ) {
                                                $vals['redirectsnippet'] = $result->getRedirectSnippet( $terms );
                                        }
                                }
                                if ( !is_null( $result->getSectionTitle() ) ) {
                                        if ( isset( $prop['sectiontitle'] ) ) {
                                                $vals['sectiontitle'] = $result->getSectionTitle()->getFragment();
                                        }
                                        if ( isset( $prop['sectionsnippet'] ) ) {
                                                $vals['sectionsnippet'] = $result->getSectionSnippet();
                                        }
                                }

                                // Add item to results and see whether it fits
                                $fit = $apiResult->addValue( array( 'query', $this->getModuleName() ),
                                        null, $vals );
                                if ( !$fit ) {
                                        $this->setContinueEnumParameter( 'offset', $params['offset'] + $count - 1 );
                                        break;
                                }
                        } else {
                                $titles[] = $title;
                        }

                        $result = $matches->next();
                }

                $hasInterwikiResults = false;
                if ( $interwiki && $resultPageSet === null && $matches->hasInterwikiResults() ) {
                        $matches = $matches->getInterwikiResults();
                        $hasInterwikiResults = true;

                        // Include number of results if requested
                        if ( isset( $searchInfo['totalhits'] ) ) {
                                $totalhits = $matches->getTotalHits();
                                if ( $totalhits !== null ) {
                                        $apiResult->addValue( array( 'query', 'interwikisearchinfo' ),
                                                'totalhits', $totalhits );
                                }
                        }

                        $result = $matches->next();
                        while ( $result ) {
                                $title = $result->getTitle();
                                $vals = array(
                                        'namespace' => $result->getInterwikiNamespaceText(),
                                        'title' => $title->getText(),
                                        'url' => $title->getFullUrl(),
                                );

                                // Add item to results and see whether it fits
                                $fit = $apiResult->addValue(
                                        array( 'query', 'interwiki' . $this->getModuleName(), $result->getInterwikiPrefix()  ),
                                        null,
                                        $vals
                                );

                                if ( !$fit ) {
                                        // We hit the limit. We can't really provide any meaningful
                                        // pagination info so just bail out
                                        break;
                                }

                                $result = $matches->next();
                        }
                }

                if ( is_null( $resultPageSet ) ) {
                        $apiResult->setIndexedTagName_internal( array(
                                'query', $this->getModuleName()
                        ), 'p' );
                        if ( $hasInterwikiResults ) {
                                $apiResult->setIndexedTagName_internal( array(
                                        'query', 'interwiki' . $this->getModuleName()
                                ), 'p' );
                        }
                } else {
                        $resultPageSet->populateFromTitles( $titles );
                }
        }

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

        public function getAllowedParams() {
                $params = array(
                        'search' => array(
                                ApiBase::PARAM_TYPE => 'string',
                                ApiBase::PARAM_REQUIRED => true
                        ),
                        'namespace' => array(
                                ApiBase::PARAM_DFLT => NS_MAIN,
                                ApiBase::PARAM_TYPE => 'namespace',
                                ApiBase::PARAM_ISMULTI => true,
                        ),
                        'what' => array(
                                ApiBase::PARAM_DFLT => null,
                                ApiBase::PARAM_TYPE => array(
                                        'title',
                                        'text',
                                        'nearmatch',
                                )
                        ),
                        'info' => array(
                                ApiBase::PARAM_DFLT => 'totalhits|suggestion',
                                ApiBase::PARAM_TYPE => array(
                                        'totalhits',
                                        'suggestion',
                                ),
                                ApiBase::PARAM_ISMULTI => true,
                        ),
                        'prop' => array(
                                ApiBase::PARAM_DFLT => 'size|wordcount|timestamp|snippet',
                                ApiBase::PARAM_TYPE => array(
                                        'size',
                                        'wordcount',
                                        'timestamp',
                                        'score',
                                        'snippet',
                                        'titlesnippet',
                                        'redirecttitle',
                                        'redirectsnippet',
                                        'sectiontitle',
                                        'sectionsnippet',
                                        'hasrelated',
                                ),
                                ApiBase::PARAM_ISMULTI => true,
                        ),
                        'offset' => 0,
                        'limit' => array(
                                ApiBase::PARAM_DFLT => 10,
                                ApiBase::PARAM_TYPE => 'limit',
                                ApiBase::PARAM_MIN => 1,
                                ApiBase::PARAM_MAX => ApiBase::LIMIT_SML1,
                                ApiBase::PARAM_MAX2 => ApiBase::LIMIT_SML2
                        ),
                        'interwiki' => false,
                );

                $alternatives = SearchEngine::getSearchTypes();
                if ( count( $alternatives ) > 1 ) {
                        if ( $alternatives[0] === null ) {
                                $alternatives[0] = self::BACKEND_NULL_PARAM;
                        }
                        $params['backend'] = array(
                                ApiBase::PARAM_DFLT => $this->getConfig()->get( 'SearchType' ),
                                ApiBase::PARAM_TYPE => $alternatives,
                        );
                }

                return $params;
        }

        public function getParamDescription() {
                $descriptions = array(
                        'search' => 'Search for all page titles (or content) that has this value',
                        'namespace' => 'The namespace(s) to enumerate',
                        'what' => 'Search inside the text or titles',
                        'info' => 'What metadata to return',
                        'prop' => array(
                                'What properties to return',
                                ' size             - Adds the size of the page in bytes',
                                ' wordcount        - Adds the word count of the page',
                                ' timestamp        - Adds the timestamp of when the page was last edited',
                                ' score            - Adds the score (if any) from the search engine',
                                ' snippet          - Adds a parsed snippet of the page',
                                ' titlesnippet     - Adds a parsed snippet of the page title',
                                ' redirectsnippet  - Adds a parsed snippet of the redirect title',
                                ' redirecttitle    - Adds the title of the matching redirect',
                                ' sectionsnippet   - Adds a parsed snippet of the matching section title',
                                ' sectiontitle     - Adds the title of the matching section',
                                ' hasrelated       - Indicates whether a related search is available',
                        ),
                        'offset' => 'Use this value to continue paging (return by query)',
                        'limit' => 'How many total pages to return',
                        'interwiki' => 'Include interwiki results in the search, if available'
                );

                if ( count( SearchEngine::getSearchTypes() ) > 1 ) {
                        $descriptions['backend'] = 'Which search backend to use, if not the default';
                }

                return $descriptions;
        }

        public function getDescription() {
                return 'Perform a full text search.';
        }

        public function getExamples() {
                return array(
                        'api.php?action=query&list=search&srsearch=meaning',
                        'api.php?action=query&list=search&srwhat=text&srsearch=meaning',
                        'api.php?action=query&generator=search&gsrsearch=meaning&prop=info',
                );
        }

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