ApiQueryCategories.php

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<?php
class ApiQueryCategories extends ApiQueryGeneratorBase {

        public function __construct( $query, $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 ) {
                if ( $this->getPageSet()->getGoodTitleCount() == 0 ) {
                        return; // nothing to do
                }

                $params = $this->extractRequestParams();
                $prop = array_flip( (array)$params['prop'] );
                $show = array_flip( (array)$params['show'] );

                $this->addFields( array(
                        'cl_from',
                        'cl_to'
                ) );

                $this->addFieldsIf( array( 'cl_sortkey', 'cl_sortkey_prefix' ), isset( $prop['sortkey'] ) );
                $this->addFieldsIf( 'cl_timestamp', isset( $prop['timestamp'] ) );

                $this->addTables( 'categorylinks' );
                $this->addWhereFld( 'cl_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
                if ( !is_null( $params['categories'] ) ) {
                        $cats = array();
                        foreach ( $params['categories'] as $cat ) {
                                $title = Title::newFromText( $cat );
                                if ( !$title || $title->getNamespace() != NS_CATEGORY ) {
                                        $this->setWarning( "\"$cat\" is not a category" );
                                } else {
                                        $cats[] = $title->getDBkey();
                                }
                        }
                        $this->addWhereFld( 'cl_to', $cats );
                }

                if ( !is_null( $params['continue'] ) ) {
                        $cont = explode( '|', $params['continue'] );
                        if ( count( $cont ) != 2 ) {
                                $this->dieUsage( "Invalid continue param. You should pass the " .
                                        "original value returned by the previous query", "_badcontinue" );
                        }
                        $op = $params['dir'] == 'descending' ? '<' : '>';
                        $clfrom = intval( $cont[0] );
                        $clto = $this->getDB()->addQuotes( $cont[1] );
                        $this->addWhere(
                                "cl_from $op $clfrom OR " .
                                "(cl_from = $clfrom AND " .
                                "cl_to $op= $clto)"
                        );
                }

                if ( isset( $show['hidden'] ) && isset( $show['!hidden'] ) ) {
                        $this->dieUsageMsg( 'show' );
                }
                if ( isset( $show['hidden'] ) || isset( $show['!hidden'] ) || isset( $prop['hidden'] ) )
                {
                        $this->addOption( 'STRAIGHT_JOIN' );
                        $this->addTables( array( 'page', 'page_props' ) );
                        $this->addFieldsIf( 'pp_propname', isset( $prop['hidden'] ) );
                        $this->addJoinConds( array(
                                'page' => array( 'LEFT JOIN', array(
                                        'page_namespace' => NS_CATEGORY,
                                        'page_title = cl_to' ) ),
                                'page_props' => array( 'LEFT JOIN', array(
                                        'pp_page=page_id',
                                        'pp_propname' => 'hiddencat' ) )
                        ) );
                        if ( isset( $show['hidden'] ) ) {
                                $this->addWhere( array( 'pp_propname IS NOT NULL' ) );
                        } elseif ( isset( $show['!hidden'] ) ) {
                                $this->addWhere( array( 'pp_propname IS NULL' ) );
                        }
                }

                $this->addOption( 'USE INDEX', array( 'categorylinks' => 'cl_from' ) );

                $sort = ( $params['dir'] == 'descending' ? ' DESC' : '' );
                // Don't order by cl_from if it's constant in the WHERE clause
                if ( count( $this->getPageSet()->getGoodTitles() ) == 1 ) {
                        $this->addOption( 'ORDER BY', 'cl_to' . $sort );
                } else {
                        $this->addOption( 'ORDER BY', array(
                                                'cl_from' . $sort,
                                                'cl_to' . $sort
                        ));
                }

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

                $count = 0;
                if ( is_null( $resultPageSet ) ) {
                        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( 'continue', $row->cl_from . '|' . $row->cl_to );
                                        break;
                                }

                                $title = Title::makeTitle( NS_CATEGORY, $row->cl_to );
                                $vals = array();
                                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'] ) && !is_null( $row->pp_propname ) ) {
                                        $vals['hidden'] = '';
                                }

                                $fit = $this->addPageSubItem( $row->cl_from, $vals );
                                if ( !$fit ) {
                                        $this->setContinueEnumParameter( 'continue', $row->cl_from . '|' . $row->cl_to );
                                        break;
                                }
                        }
                } else {
                        $titles = array();
                        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( 'continue', $row->cl_from . '|' . $row->cl_to );
                                        break;
                                }

                                $titles[] = Title :: makeTitle( NS_CATEGORY, $row->cl_to );
                        }
                        $resultPageSet->populateFromTitles( $titles );
                }
        }

        public function getAllowedParams() {
                return array(
                        'prop' => array(
                                ApiBase::PARAM_ISMULTI => true,
                                ApiBase::PARAM_TYPE => array (
                                        'sortkey',
                                        'timestamp',
                                        'hidden',
                                )
                        ),
                        'show' => array(
                                ApiBase::PARAM_ISMULTI => true,
                                ApiBase::PARAM_TYPE => array(
                                        'hidden',
                                        '!hidden',
                                )
                        ),
                        '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
                        ),
                        'continue' => null,
                        'categories' => array(
                                ApiBase::PARAM_ISMULTI => true,
                        ),
                        'dir' => array(
                                ApiBase::PARAM_DFLT => 'ascending',
                                ApiBase::PARAM_TYPE => array(
                                        'ascending',
                                        'descending'
                                )
                        ),
                );
        }

        public function getParamDescription() {
                return array(
                        'prop' => array(
                                'Which additional properties to get for each category',
                                ' sortkey    - Adds the sortkey (hexadecimal string) and sortkey prefix (human-readable part) for the category',
                                ' timestamp  - Adds timestamp of when the category was added',
                                ' hidden     - Tags categories that are hidden with __HIDDENCAT__',
                        ),
                        'limit' => 'How many categories to return',
                        'show' => 'Which kind of categories to show',
                        'continue' => 'When more results are available, use this to continue',
                        'categories' => 'Only list these categories. Useful for checking whether a certain page is in a certain category',
                        'dir' => 'The direction in which to list',
                );
        }

        public function getResultProperties() {
                return array(
                        '' => array(
                                'ns' => 'namespace',
                                'title' => 'string'
                        ),
                        'sortkey' => array(
                                'sortkey' => 'string',
                                'sortkeyprefix' => 'string'
                        ),
                        'timestamp' => array(
                                'timestamp' => 'timestamp'
                        ),
                        'hidden' => array(
                                'hidden' => 'boolean'
                        )
                );
        }

        public function getDescription() {
                return 'List all categories the page(s) belong to';
        }

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

        public function getExamples() {
                return array(
                        'api.php?action=query&prop=categories&titles=Albert%20Einstein' => 'Get a list of categories [[Albert Einstein]] belongs to',
                        'api.php?action=query&generator=categories&titles=Albert%20Einstein&prop=info' => 'Get information about all categories used in the [[Albert Einstein]]',
                );
        }

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

        public function getVersion() {
                return __CLASS__ . ': $Id$';
        }
}