* Removed inconsistent hard coding of colons

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

<?php

/*
 * Created on Oct 16, 2006
 *
 * API for MediaWiki 1.8+
 *
 * Copyright (C) 2006 Yuri Astrakhan <FirstnameLastname@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.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 * http://www.gnu.org/copyleft/gpl.html
 */

if (!defined('MEDIAWIKI')) {
        // Eclipse helper - will be ignored in production
        require_once ("ApiQueryBase.php");
}

/**
 * @addtogroup API
 */
class ApiQueryBacklinks extends ApiQueryGeneratorBase {

        private $rootTitle, $contRedirs, $contLevel, $contTitle, $contID;

        // output element name, database column field prefix, database table 
        private $backlinksSettings = array (
                'backlinks' => array (
                        'code' => 'bl',
                        'prefix' => 'pl',
                        'linktbl' => 'pagelinks'
                ),
                'embeddedin' => array (
                        'code' => 'ei',
                        'prefix' => 'tl',
                        'linktbl' => 'templatelinks'
                ),
                'imagelinks' => array (
                        'code' => 'il',
                        'prefix' => 'il',
                        'linktbl' => 'imagelinks'
                )
        );

        public function __construct($query, $moduleName) {
                $code = $prefix = $linktbl = null;
                extract($this->backlinksSettings[$moduleName]);

                parent :: __construct($query, $moduleName, $code);
                $this->bl_ns = $prefix . '_namespace';
                $this->bl_from = $prefix . '_from';
                $this->bl_tables = array (
                        $linktbl,
                        'page'
                );
                $this->bl_code = $code;

                $this->hasNS = $moduleName !== 'imagelinks';
                if ($this->hasNS) {
                        $this->bl_title = $prefix . '_title';
                        $this->bl_sort = "{$this->bl_ns}, {$this->bl_title}, {$this->bl_from}";
                        $this->bl_fields = array (
                                $this->bl_ns,
                                $this->bl_title
                        );
                } else {
                        $this->bl_title = $prefix . '_to';
                        $this->bl_sort = "{$this->bl_title}, {$this->bl_from}";
                        $this->bl_fields = array (
                                $this->bl_title
                        );
                }
        }

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

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

        private function run($resultPageSet = null) {
                $continue = $namespace = $redirect = $limit = null;
                extract($this->extractRequestParams());

                if ($redirect)
                        ApiBase :: dieDebug(__METHOD__, 'Redirect is not yet been implemented', 'notimplemented');

                $this->processContinue($continue, $redirect);

                $this->addFields($this->bl_fields);
                if (is_null($resultPageSet))
                        $this->addFields(array (
                                'page_id',
                                'page_namespace',
                                'page_title'
                        ));
                else
                        $this->addFields($resultPageSet->getPageTableFields()); // will include page_id

                $this->addTables($this->bl_tables);
                $this->addWhere($this->bl_from . '=page_id');

                if ($this->hasNS)
                        $this->addWhereFld($this->bl_ns, $this->rootTitle->getNamespace());
                $this->addWhereFld($this->bl_title, $this->rootTitle->getDBkey());
                $this->addWhereFld('page_namespace', $namespace);
                $this->addOption('LIMIT', $limit +1);
                $this->addOption('ORDER BY', $this->bl_sort);

                if ($redirect)
                        $this->addWhereFld('page_is_redirect', 0);

                $db = $this->getDB();
                if (!is_null($continue)) {
                        $plfrm = intval($this->contID);
                        if ($this->contLevel == 0) {
                                // For the first level, there is only one target title, so no need for complex filtering
                                $this->addWhere($this->bl_from . '>=' . $plfrm);
                        } else {
                                $ns = $this->contTitle->getNamespace();
                                $t = $db->addQuotes($this->contTitle->getDBkey());
                                $whereWithoutNS = "{$this->bl_title}>$t OR ({$this->bl_title}=$t AND {$this->bl_from}>=$plfrm))";

                                if ($this->hasNS)
                                        $this->addWhere("{$this->bl_ns}>$ns OR ({$this->bl_ns}=$ns AND ($whereWithoutNS)");
                                else
                                        $this->addWhere($whereWithoutNS);
                        }
                }

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

                $count = 0;
                $data = array ();
                while ($row = $db->fetchObject($res)) {
                        if (++ $count > $limit) {
                                // We've reached the one extra which shows that there are additional pages to be had. Stop here...
                                if ($redirect) {
                                        $ns = $row-> {
                                                $this->bl_ns };
                                        $t = $row-> {
                                                $this->bl_title };
                                        $continue = $this->getContinueRedirStr(false, 0, $ns, $t, $row->page_id);
                                } else
                                        $continue = $this->getContinueStr($row->page_id);
                                $this->setContinueEnumParameter('continue', $continue);
                                break;
                        }

                        if (is_null($resultPageSet)) {
                                $vals = $this->addRowInfo('page', $row);
                                if ($vals)
                                        $data[intval($row->page_id)] = $vals;
                        } else {
                                $resultPageSet->processDbRow($row);
                        }
                }
                $db->freeResult($res);

                if (is_null($resultPageSet)) {
                        $result = $this->getResult();
                        $result->setIndexedTagName($data, $this->bl_code);
                        $result->addValue('query', $this->getModuleName(), $data);
                }
        }

        protected function processContinue($continue, $redirect) {
                $pageSet = $this->getPageSet();
                $count = $pageSet->getTitleCount();
                if (!is_null($continue)) {
                        if ($count !== 0)
                                $this->dieUsage("When continuing the {$this->getModuleName()} query, no other titles may be provided", 'titles_on_continue');
                        $this->parseContinueParam($continue, $redirect);

                        // Skip all completed links

                } else {
                        if ($count !== 1)
                                $this->dieUsage("The {$this->getModuleName()} query requires one title to start", 'bad_title_count');
                        $this->rootTitle = current($pageSet->getTitles()); // only one title there
                }

                // only image titles are allowed for the root 
                if (!$this->hasNS && $this->rootTitle->getNamespace() !== NS_IMAGE)
                        $this->dieUsage("The title for {$this->getModuleName()} query must be an image", 'bad_image_title');
        }

        protected function parseContinueParam($continue, $redirect) {
                $continueList = explode('|', $continue);
                if ($redirect) {
                        //
                        // expected redirect-mode parameter:
                        // ns|db_key|step|level|ns|db_key|id
                        // ns+db_key -- the root title
                        // step = 1 or 2 - which step to continue from - 1-titles, 2-redirects
                        // level -- how many levels to follow before starting enumerating.
                        // if level > 0 -- ns+title to continue from, otherwise skip these 
                        // id = last page_id to continue from
                        //
                        if (count($continueList) > 4) {
                                $rootNs = intval($continueList[0]);
                                if (($rootNs !== 0 || $continueList[0] === '0') && !empty ($continueList[1])) {
                                        $this->rootTitle = Title :: makeTitleSafe($rootNs, $continueList[1]);
                                        if ($this->rootTitle && $this->rootTitle->userCanRead()) {

                                                $step = intval($continueList[2]);
                                                if ($step === 1 || $step === 2) {
                                                        $this->contRedirs = ($step === 2);

                                                        $level = intval($continueList[3]);
                                                        if ($level !== 0 || $continueList[3] === '0') {
                                                                $this->contLevel = $level;

                                                                if ($level === 0) {
                                                                        if (count($continueList) === 5) {
                                                                                $contID = intval($continueList[4]);
                                                                                if ($contID !== 0 || $continueList[4] === '0') {
                                                                                        $this->contID = $contID;
                                                                                        return; // done
                                                                                }
                                                                        }
                                                                } else {
                                                                        if (count($continueList) === 7) {
                                                                                $contNs = intval($continueList[4]);
                                                                                if (($contNs !== 0 || $continueList[4] === '0') && !empty ($continueList[5])) {
                                                                                        $this->contTitle = Title :: makeTitleSafe($contNs, $continueList[5]);

                                                                                        $contID = intval($continueList[6]);
                                                                                        if ($contID !== 0 || $continueList[6] === '0') {
                                                                                                $this->contID = $contID;
                                                                                                return; // done
                                                                                        }
                                                                                }
                                                                        }
                                                                }
                                                        }
                                                }
                                        }
                                }
                        }
                } else {
                        //
                        // expected non-redirect-mode parameter:
                        // ns|db_key|id
                        // ns+db_key -- the root title
                        // id = last page_id to continue from
                        //
                        if (count($continueList) === 3) {
                                $rootNs = intval($continueList[0]);
                                if (($rootNs !== 0 || $continueList[0] === '0') && !empty ($continueList[1])) {
                                        $this->rootTitle = Title :: makeTitleSafe($rootNs, $continueList[1]);
                                        if ($this->rootTitle && $this->rootTitle->userCanRead()) {

                                                $contID = intval($continueList[2]);
                                                if ($contID !== 0) {
                                                        $this->contID = $contID;
                                                        return; // done
                                                }
                                        }
                                }
                        }
                }

                $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "_badcontinue");
        }

        protected function getContinueStr($lastPageID) {
                return $this->rootTitle->getNamespace() .
                '|' . $this->rootTitle->getDBkey() .
                '|' . $lastPageID;
        }

        protected function getContinueRedirStr($isRedirPhase, $level, $ns, $title, $lastPageID) {
                return $this->rootTitle->getNamespace() .
                '|' . $this->rootTitle->getDBkey() .
                '|' . ($isRedirPhase ? 1 : 2) .
                '|' . $level .
                 ($level > 0 ? ('|' . $ns . '|' . $title) : '') .
                '|' . $lastPageID;
        }

        protected function getAllowedParams() {

                return array (
                        'continue' => null,
                        'namespace' => array (
                                ApiBase :: PARAM_ISMULTI => true,
                                ApiBase :: PARAM_TYPE => 'namespace'
                        ),
                        'redirect' => false,
                        'limit' => array (
                                ApiBase :: PARAM_DFLT => 10,
                                ApiBase :: PARAM_TYPE => 'limit',
                                ApiBase :: PARAM_MIN => 1,
                                ApiBase :: PARAM_MAX1 => ApiBase :: LIMIT_BIG1,
                                ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
                        )
                );
        }

        protected function getParamDescription() {
                return array (
                        'continue' => 'When more results are available, use this to continue.',
                        'namespace' => 'The namespace to enumerate.',
                        'redirect' => 'If linking page is a redirect, find all pages that link to that redirect (not implemented)',
                        'limit' => 'How many total pages to return.'
                );
        }

        protected function getDescription() {
                switch ($this->getModuleName()) {
                        case 'backlinks' :
                                return 'Find all pages that link to the given page';
                        case 'embeddedin' :
                                return 'Find all pages that embed (transclude) the given title';
                        case 'imagelinks' :
                                return 'Find all pages that use the given image title.';
                        default :
                                ApiBase :: dieDebug(__METHOD__, 'Unknown module name');
                }
        }

        protected function getExamples() {
                static $examples = array (
                        'backlinks' => array (
                                "api.php?action=query&list=backlinks&titles=Main%20Page",
                                "api.php?action=query&generator=backlinks&titles=Main%20Page&prop=info"
                        ),
                        'embeddedin' => array (
                                "api.php?action=query&list=embeddedin&titles=Template:Stub",
                                "api.php?action=query&generator=embeddedin&titles=Template:Stub&prop=info"
                        ),
                        'imagelinks' => array (
                                "api.php?action=query&list=imagelinks&titles=Image:Albert%20Einstein%20Head.jpg",
                                "api.php?action=query&generator=imagelinks&titles=Image:Albert%20Einstein%20Head.jpg&prop=info"
                        )
                );

                return $examples[$this->getModuleName()];
        }

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