ApiQueryCategoryMembers.php

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<?php
class ApiQueryCategoryMembers extends ApiQueryGeneratorBase {

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

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

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

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

        private function run( $resultPageSet = null ) {
                $params = $this->extractRequestParams();

                $categoryTitle = $this->getTitleOrPageId( $params )->getTitle();
                if ( $categoryTitle->getNamespace() != NS_CATEGORY ) {
                        $this->dieUsage( 'The category name you entered is not valid', 'invalidcategory' );
                }

                $prop = array_flip( $params['prop'] );
                $fld_ids = isset( $prop['ids'] );
                $fld_title = isset( $prop['title'] );
                $fld_sortkey = isset( $prop['sortkey'] );
                $fld_sortkeyprefix = isset( $prop['sortkeyprefix'] );
                $fld_timestamp = isset( $prop['timestamp'] );
                $fld_type = isset( $prop['type'] );

                if ( is_null( $resultPageSet ) ) {
                        $this->addFields( array( 'cl_from', 'cl_sortkey', 'cl_type', 'page_namespace', 'page_title' ) );
                        $this->addFieldsIf( 'page_id', $fld_ids );
                        $this->addFieldsIf( 'cl_sortkey_prefix', $fld_sortkeyprefix );
                } else {
                        $this->addFields( $resultPageSet->getPageTableFields() ); // will include page_ id, ns, title
                        $this->addFields( array( 'cl_from', 'cl_sortkey', 'cl_type' ) );
                }

                $this->addFieldsIf( 'cl_timestamp', $fld_timestamp || $params['sort'] == 'timestamp' );

                $this->addTables( array( 'page', 'categorylinks' ) );   // must be in this order for 'USE INDEX'

                $this->addWhereFld( 'cl_to', $categoryTitle->getDBkey() );
                $queryTypes = $params['type'];
                $contWhere = false;

                // Scanning large datasets for rare categories sucks, and I already told
                // how to have efficient subcategory access :-) ~~~~ (oh well, domas)
                global $wgMiserMode;
                $miser_ns = array();
                if ( $wgMiserMode ) {
                        $miser_ns = $params['namespace'];
                } else {
                        $this->addWhereFld( 'page_namespace', $params['namespace'] );
                }

                $dir = in_array( $params['dir'], array( 'asc', 'ascending', 'newer' ) ) ? 'newer' : 'older';

                if ( $params['sort'] == 'timestamp' ) {
                        $this->addTimestampWhereRange( 'cl_timestamp',
                                $dir,
                                $params['start'],
                                $params['end'] );

                        $this->addOption( 'USE INDEX', 'cl_timestamp' );
                } else {
                        if ( $params['continue'] ) {
                                $cont = explode( '|', $params['continue'], 3 );
                                if ( count( $cont ) != 3 ) {
                                        $this->dieUsage( 'Invalid continue param. You should pass the original value returned '.
                                                'by the previous query', '_badcontinue'
                                        );
                                }

                                // Remove the types to skip from $queryTypes
                                $contTypeIndex = array_search( $cont[0], $queryTypes );
                                $queryTypes = array_slice( $queryTypes, $contTypeIndex );

                                // Add a WHERE clause for sortkey and from
                                // pack( "H*", $foo ) is used to convert hex back to binary
                                $escSortkey = $this->getDB()->addQuotes( pack( "H*", $cont[1] ) );
                                $from = intval( $cont[2] );
                                $op = $dir == 'newer' ? '>' : '<';
                                // $contWhere is used further down
                                $contWhere = "cl_sortkey $op $escSortkey OR " .
                                        "(cl_sortkey = $escSortkey AND " .
                                        "cl_from $op= $from)";
                                // The below produces ORDER BY cl_sortkey, cl_from, possibly with DESC added to each of them
                                $this->addWhereRange( 'cl_sortkey', $dir, null, null );
                                $this->addWhereRange( 'cl_from', $dir, null, null );
                        } else {
                                $startsortkey = $params['startsortkeyprefix'] !== null ?
                                        Collation::singleton()->getSortkey( $params['startsortkeyprefix'] ) :
                                        $params['startsortkey'];
                                $endsortkey = $params['endsortkeyprefix'] !== null ?
                                        Collation::singleton()->getSortkey( $params['endsortkeyprefix'] ) :
                                        $params['endsortkey'];

                                // The below produces ORDER BY cl_sortkey, cl_from, possibly with DESC added to each of them
                                $this->addWhereRange( 'cl_sortkey',
                                        $dir,
                                        $startsortkey,
                                        $endsortkey );
                                $this->addWhereRange( 'cl_from', $dir, null, null );
                        }
                        $this->addOption( 'USE INDEX', 'cl_sortkey' );
                }

                $this->addWhere( 'cl_from=page_id' );

                $limit = $params['limit'];
                $this->addOption( 'LIMIT', $limit + 1 );

                if ( $params['sort'] == 'sortkey' ) {
                        // Run a separate SELECT query for each value of cl_type.
                        // This is needed because cl_type is an enum, and MySQL has
                        // inconsistencies between ORDER BY cl_type and
                        // WHERE cl_type >= 'foo' making proper paging impossible
                        // and unindexed.
                        $rows = array();
                        $first = true;
                        foreach ( $queryTypes as $type ) {
                                $extraConds = array( 'cl_type' => $type );
                                if ( $first && $contWhere ) {
                                        // Continuation condition. Only added to the
                                        // first query, otherwise we'll skip things
                                        $extraConds[] = $contWhere;
                                }
                                $res = $this->select( __METHOD__, array( 'where' => $extraConds ) );
                                $rows = array_merge( $rows, iterator_to_array( $res ) );
                                if ( count( $rows ) >= $limit + 1 ) {
                                        break;
                                }
                                $first = false;
                        }
                } else {
                        // Sorting by timestamp
                        // No need to worry about per-type queries because we
                        // aren't sorting or filtering by type anyway
                        $res = $this->select( __METHOD__ );
                        $rows = iterator_to_array( $res );
                }

                $result = $this->getResult();
                $count = 0;
                foreach ( $rows as $row ) {
                        if ( ++ $count > $limit ) {
                                // We've reached the one extra which shows that there are additional pages to be had. Stop here...
                                // TODO: Security issue - if the user has no right to view next title, it will still be shown
                                if ( $params['sort'] == 'timestamp' ) {
                                        $this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->cl_timestamp ) );
                                } else {
                                        $sortkey = bin2hex( $row->cl_sortkey );
                                        $this->setContinueEnumParameter( 'continue',
                                                "{$row->cl_type}|$sortkey|{$row->cl_from}"
                                        );
                                }
                                break;
                        }

                        // Since domas won't tell anyone what he told long ago, apply
                        // cmnamespace here. This means the query may return 0 actual
                        // results, but on the other hand it could save returning 5000
                        // useless results to the client. ~~~~
                        if ( count( $miser_ns ) && !in_array( $row->page_namespace, $miser_ns ) ) {
                                continue;
                        }

                        if ( is_null( $resultPageSet ) ) {
                                $vals = array();
                                if ( $fld_ids ) {
                                        $vals['pageid'] = intval( $row->page_id );
                                }
                                if ( $fld_title ) {
                                        $title = Title::makeTitle( $row->page_namespace, $row->page_title );
                                        ApiQueryBase::addTitleInfo( $vals, $title );
                                }
                                if ( $fld_sortkey ) {
                                        $vals['sortkey'] = bin2hex( $row->cl_sortkey );
                                }
                                if ( $fld_sortkeyprefix ) {
                                        $vals['sortkeyprefix'] = $row->cl_sortkey_prefix;
                                }
                                if ( $fld_type  ) {
                                        $vals['type'] = $row->cl_type;
                                }
                                if ( $fld_timestamp ) {
                                        $vals['timestamp'] = wfTimestamp( TS_ISO_8601, $row->cl_timestamp );
                                }
                                $fit = $result->addValue( array( 'query', $this->getModuleName() ),
                                                null, $vals );
                                if ( !$fit ) {
                                        if ( $params['sort'] == 'timestamp' ) {
                                                $this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->cl_timestamp ) );
                                        } else {
                                                $sortkey = bin2hex( $row->cl_sortkey );
                                                $this->setContinueEnumParameter( 'continue',
                                                        "{$row->cl_type}|$sortkey|{$row->cl_from}"
                                                );
                                        }
                                        break;
                                }
                        } else {
                                $resultPageSet->processDbRow( $row );
                        }
                }

                if ( is_null( $resultPageSet ) ) {
                        $result->setIndexedTagName_internal(
                                         array( 'query', $this->getModuleName() ), 'cm' );
                }
        }

        public function getAllowedParams() {
                return array(
                        'title' => array(
                                ApiBase::PARAM_TYPE => 'string',
                        ),
                        'pageid' => array(
                                ApiBase::PARAM_TYPE => 'integer'
                        ),
                        'prop' => array(
                                ApiBase::PARAM_DFLT => 'ids|title',
                                ApiBase::PARAM_ISMULTI => true,
                                ApiBase::PARAM_TYPE => array (
                                        'ids',
                                        'title',
                                        'sortkey',
                                        'sortkeyprefix',
                                        'type',
                                        'timestamp',
                                )
                        ),
                        'namespace' => array (
                                ApiBase::PARAM_ISMULTI => true,
                                ApiBase::PARAM_TYPE => 'namespace',
                        ),
                        'type' => array(
                                ApiBase::PARAM_ISMULTI => true,
                                ApiBase::PARAM_DFLT => 'page|subcat|file',
                                ApiBase::PARAM_TYPE => array(
                                        'page',
                                        'subcat',
                                        'file'
                                )
                        ),
                        'continue' => null,
                        'limit' => array(
                                ApiBase::PARAM_TYPE => 'limit',
                                ApiBase::PARAM_DFLT => 10,
                                ApiBase::PARAM_MIN => 1,
                                ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
                                ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
                        ),
                        'sort' => array(
                                ApiBase::PARAM_DFLT => 'sortkey',
                                ApiBase::PARAM_TYPE => array(
                                        'sortkey',
                                        'timestamp'
                                )
                        ),
                        'dir' => array(
                                ApiBase::PARAM_DFLT => 'ascending',
                                ApiBase::PARAM_TYPE => array(
                                        'asc',
                                        'desc',
                                        // Normalising with other modules
                                        'ascending',
                                        'descending',
                                        'newer',
                                        'older',
                                )
                        ),
                        'start' => array(
                                ApiBase::PARAM_TYPE => 'timestamp'
                        ),
                        'end' => array(
                                ApiBase::PARAM_TYPE => 'timestamp'
                        ),
                        'startsortkey' => null,
                        'endsortkey' => null,
                        'startsortkeyprefix' => null,
                        'endsortkeyprefix' => null,
                );
        }

        public function getParamDescription() {
                global $wgMiserMode;
                $p = $this->getModulePrefix();
                $desc = array(
                        'title' => "Which category to enumerate (required). Must include Category: prefix. Cannot be used together with {$p}pageid",
                        'pageid' => "Page ID of the category to enumerate. Cannot be used together with {$p}title",
                        'prop' => array(
                                'What pieces of information to include',
                                ' ids           - Adds the page ID',
                                ' title         - Adds the title and namespace ID of the page',
                                ' sortkey       - Adds the sortkey used for sorting in the category (hexadecimal string)',
                                ' sortkeyprefix - Adds the sortkey prefix used for sorting in the category (human-readable part of the sortkey)',
                                ' type          - Adds the type that the page has been categorised as (page, subcat or file)',
                                ' timestamp     - Adds the timestamp of when the page was included',
                        ),
                        'namespace' => 'Only include pages in these namespaces',
                        'type' => "What type of category members to include. Ignored when {$p}sort=timestamp is set",
                        'sort' => 'Property to sort by',
                        'dir' => 'In which direction to sort',
                        'start' => "Timestamp to start listing from. Can only be used with {$p}sort=timestamp",
                        'end' => "Timestamp to end listing at. Can only be used with {$p}sort=timestamp",
                        'startsortkey' => "Sortkey to start listing from. Must be given in binary format. Can only be used with {$p}sort=sortkey",
                        'endsortkey' => "Sortkey to end listing at. Must be given in binary format. Can only be used with {$p}sort=sortkey",
                        'startsortkeyprefix' => "Sortkey prefix to start listing from. Can only be used with {$p}sort=sortkey. Overrides {$p}startsortkey",
                        'endsortkeyprefix' => "Sortkey prefix to end listing BEFORE (not at, if this value occurs it will not be included!). Can only be used with {$p}sort=sortkey. Overrides {$p}endsortkey",
                        'continue' => 'For large categories, give the value returned from previous query',
                        'limit' => 'The maximum number of pages to return.',
                );

                if ( $wgMiserMode ) {
                        $desc['namespace'] = array(
                                $desc['namespace'],
                                "NOTE: Due to \$wgMiserMode, using this may result in fewer than \"{$p}limit\" results",
                                'returned before continuing; in extreme cases, zero results may be returned.',
                                "Note that you can use {$p}type=subcat or {$p}type=file instead of {$p}namespace=14 or 6.",
                        );
                }
                return $desc;
        }

        public function getResultProperties() {
                return array(
                        'ids' => array(
                                'pageid' => 'integer'
                        ),
                        'title' => array(
                                'ns' => 'namespace',
                                'title' => 'string'
                        ),
                        'sortkey' => array(
                                'sortkey' => 'string'
                        ),
                        'sortkeyprefix' => array(
                                'sortkeyprefix' => 'string'
                        ),
                        'type' => array(
                                'type' => array(
                                        ApiBase::PROP_TYPE => array(
                                                'page',
                                                'subcat',
                                                'file'
                                        )
                                )
                        ),
                        'timestamp' => array(
                                'timestamp' => 'timestamp'
                        )
                );
        }

        public function getDescription() {
                return 'List all pages in a given category';
        }

        public function getPossibleErrors() {
                return array_merge( parent::getPossibleErrors(),
                        $this->getTitleOrPageIdErrorMessage(),
                        array(
                                array( 'code' => 'invalidcategory', 'info' => 'The category name you entered is not valid' ),
                                array( 'code' => 'badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
                        )
                );
        }

        public function getExamples() {
                return array(
                        'api.php?action=query&list=categorymembers&cmtitle=Category:Physics' => 'Get first 10 pages in [[Category:Physics]]',
                        'api.php?action=query&generator=categorymembers&gcmtitle=Category:Physics&prop=info' => 'Get page info about first 10 pages in [[Category:Physics]]',
                );
        }

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

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