ApiQueryCategories.php

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<?php
namespace MediaWiki\Api;
 
use MediaWiki\Deferred\LinksUpdate\CategoryLinksTable;
use MediaWiki\Title\Title;
use Wikimedia\ParamValidator\ParamValidator;
use Wikimedia\ParamValidator\TypeDef\IntegerDef;
use Wikimedia\Timestamp\TimestampFormat as TS;
 
class ApiQueryCategories extends ApiQueryGeneratorBase {
 
    public function __construct( ApiQuery $query, string $moduleName ) {
        parent::__construct( $query, $moduleName, 'cl' );
    }
 
    public function execute() {
        $this->run();
    }
 
    public function getCacheMode( $params ) {
        return 'public';
    }
 
    public function executeGenerator( $resultPageSet ) {
        $this->run( $resultPageSet );
    }
 
    private function run( $resultPageSet = null ) {
        $pages = $this->getPageSet()->getGoodPages();
        if ( $pages === [] ) {
            return; // nothing to do
        }
 
        $params = $this->extractRequestParams();
        $prop = array_fill_keys( (array)$params['prop'], true );
        $show = array_fill_keys( (array)$params['show'], true );
 
        $cats = [];
        if ( $params['categories'] ) {
            foreach ( $params['categories'] as $cat ) {
                $title = Title::newFromText( $cat );
                if ( !$title || $title->getNamespace() !== NS_CATEGORY ) {
                    $this->addWarning( [ 'apiwarn-invalidcategory', wfEscapeWikiText( $cat ) ] );
                } else {
                    $cats[] = $title->getDBkey();
                }
            }
 
            if ( !$cats ) {
                // No titles so no results
                return;
            }
        }
 
        $filteredRows = [];
        $hiddenCategories = [];
        $needHidden = isset( $prop['hidden'] ) || isset( $show['!hidden'] ) || isset( $show['hidden'] );
        $needFiltering = isset( $show['hidden'] ) || isset( $show['!hidden'] );
 
        $continueFrom = null;
        if ( $params['continue'] !== null ) {
            $cont = $this->parseContinueParamOrDie( $params['continue'], [ 'int', 'string' ] );
            $continueFrom = [ $cont[0], $cont[1] ];
        }
 
        $db = $this->getDB();
 
        $this->setVirtualDomain( CategoryLinksTable::VIRTUAL_DOMAIN );
        $categoryLinksDb = $this->getDB();
 
        $fields = [ 'cl_from', 'lt_title' ];
        if ( isset( $prop['sortkey'] ) ) {
            $fields[] = 'cl_sortkey';
            $fields[] = 'cl_sortkey_prefix';
        }
        if ( isset( $prop['timestamp'] ) ) {
            $fields[] = 'cl_timestamp';
        }
 
        $isFirstBatch = true;
        $loopCount = 0;
        $maxLoops = 20;
        while ( count( $filteredRows ) < $params['limit'] + 1 ) {
            if ( $loopCount > $maxLoops ) {
                // Safety limit to prevent excessive iterations
                break;
            }
 
            $queryBuilder = $categoryLinksDb->newSelectQueryBuilder()
                ->select( $fields )
                ->from( 'categorylinks' )
                ->join( 'linktarget', null, 'cl_target_id = lt_id' )
                ->where( [ 'cl_from' => array_keys( $pages ), 'lt_namespace' => NS_CATEGORY ] )
                ->caller( __METHOD__ );
 
            if ( $cats !== [] ) {
                $queryBuilder->andWhere( [ 'lt_title' => $cats ] );
            }
 
            if ( $continueFrom !== null ) {
                // Use strict comparison for subsequent batches to skip the continue row
                if ( $isFirstBatch ) {
                    $op = $params['dir'] == 'descending' ? '<=' : '>=';
                } else {
                    $op = $params['dir'] == 'descending' ? '<' : '>';
                }
                $queryBuilder->andWhere( $categoryLinksDb->buildComparison( $op, [
                    'cl_from' => $continueFrom[0],
                    'lt_title' => $continueFrom[1],
                ] ) );
            }
 
            $sort = ( $params['dir'] == 'descending' ? ' DESC' : '' );
            if ( count( $pages ) === 1 ) {
                $queryBuilder->orderBy( 'lt_title' . $sort );
            } else {
                $queryBuilder->orderBy( [ 'cl_from' . $sort, 'lt_title' . $sort ] );
            }
            $queryBuilder->limit( $params['limit'] + 1 );
 
            $res = $queryBuilder->fetchResultSet();
 
            $isFirstBatch = false;
 
            $batchRows = [];
            $categories = [];
 
            foreach ( $res as $row ) {
                $batchRows[] = $row;
                $categories[] = $row->lt_title;
            }
 
            if ( $categories === [] ) {
                // No more rows available
                break;
            }
 
            if ( $needHidden ) {
                $hiddenQueryBuilder = $db->newSelectQueryBuilder()
                    ->select( [ 'pp_page', 'pp_propname', 'page_title' ] )
                    ->from( 'page_props' )
                    ->join( 'page', null, 'page_id = pp_page' )
                    ->where( [
                        'pp_propname' => 'hiddencat',
                        'page_namespace' => NS_CATEGORY,
                        'page_title' => $categories
                    ] )
                    ->caller( __METHOD__ );
 
                $hiddenRes = $hiddenQueryBuilder->fetchResultSet();
 
                foreach ( $hiddenRes as $hiddenRow ) {
                    $hiddenCategories[$hiddenRow->page_title] = true;
                }
            }
 
            if ( $needFiltering ) {
                foreach ( $batchRows as $row ) {
                    if ( isset( $show['hidden'] ) === isset( $hiddenCategories[$row->lt_title] ) ) {
                        $filteredRows[] = $row;
                    }
                }
            } else {
                $filteredRows = array_merge( $filteredRows, $batchRows );
            }
 
            if ( count( $batchRows ) < $params['limit'] + 1 ) {
                break;
            }
 
            $loopCount++;
            $lastRow = end( $batchRows );
            $continueFrom = [ $lastRow->cl_from, $lastRow->lt_title ];
        }
 
        $this->resetVirtualDomain();
 
        $count = 0;
        if ( $resultPageSet === null ) {
            foreach ( $filteredRows 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->cl_from . '|' . $row->lt_title );
                    break;
                }
 
                $title = Title::makeTitle( NS_CATEGORY, $row->lt_title );
                $vals = [];
                ApiQueryBase::addTitleInfo( $vals, $title );
                if ( isset( $prop['sortkey'] ) ) {
                    $vals['sortkey'] = bin2hex( $row->cl_sortkey );
                    $vals['sortkeyprefix'] = $row->cl_sortkey_prefix;
                }
                if ( isset( $prop['timestamp'] ) ) {
                    $vals['timestamp'] = wfTimestamp( TS::ISO_8601, $row->cl_timestamp );
                }
                if ( isset( $prop['hidden'] ) ) {
                    $vals['hidden'] = isset( $hiddenCategories[$row->lt_title] );
                }
 
                $fit = $this->addPageSubItem( $row->cl_from, $vals );
                if ( !$fit ) {
                    $this->setContinueEnumParameter( 'continue', $row->cl_from . '|' . $row->lt_title );
                    break;
                }
            }
        } else {
            $titles = [];
            foreach ( $filteredRows 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->cl_from . '|' . $row->lt_title );
                    break;
                }
 
                $titles[] = Title::makeTitle( NS_CATEGORY, $row->lt_title );
            }
            $resultPageSet->populateFromTitles( $titles );
        }
    }
 
    public function getAllowedParams() {
        return [
            'prop' => [
                ParamValidator::PARAM_ISMULTI => true,
                ParamValidator::PARAM_TYPE => [
                    'sortkey',
                    'timestamp',
                    'hidden',
                ],
                ApiBase::PARAM_HELP_MSG_PER_VALUE => [],
            ],
            'show' => [
                ParamValidator::PARAM_ISMULTI => true,
                ParamValidator::PARAM_TYPE => [
                    'hidden',
                    '!hidden',
                ]
            ],
            'limit' => [
                ParamValidator::PARAM_DEFAULT => 10,
                ParamValidator::PARAM_TYPE => 'limit',
                IntegerDef::PARAM_MIN => 1,
                IntegerDef::PARAM_MAX => ApiBase::LIMIT_BIG1,
                IntegerDef::PARAM_MAX2 => ApiBase::LIMIT_BIG2
            ],
            'continue' => [
                ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
            ],
            'categories' => [
                ParamValidator::PARAM_ISMULTI => true,
            ],
            'dir' => [
                ParamValidator::PARAM_DEFAULT => 'ascending',
                ParamValidator::PARAM_TYPE => [
                    'ascending',
                    'descending'
                ]
            ],
        ];
    }
 
    protected function getExamplesMessages() {
        return [
            'action=query&prop=categories&titles=Albert%20Einstein'
                => 'apihelp-query+categories-example-simple',
            'action=query&generator=categories&titles=Albert%20Einstein&prop=info'
                => 'apihelp-query+categories-example-generator',
        ];
    }
 
    public function getHelpUrls() {
        return 'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Categories';
    }
}
 
class_alias( ApiQueryCategories::class, 'ApiQueryCategories' );