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'] );
            $this->dieContinueUsageIf( count( $cont ) != 2 );
            $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';
    }
}