includes/api/ApiQuery.php

   1 <?php
   2
   3 /*
   4  * Created on Sep 7, 2006
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  */
  25
  26 if (!defined('MEDIAWIKI')) {
  27         // Eclipse helper - will be ignored in production
  28         require_once ('ApiBase.php');
  29 }
  30
  31 /**
  32  * This is the main query class. It behaves similar to ApiMain: based on the parameters given,
  33  * it will create a list of titles to work on (an instance of the ApiPageSet object)
  34  * instantiate and execute various property/list/meta modules,
  35  * and assemble all resulting data into a single ApiResult object.
  36  *
  37  * In the generator mode, a generator will be first executed to populate a second ApiPageSet object,
  38  * and that object will be used for all subsequent modules.
  39  *
  40  * @addtogroup API
  41  */
  42 class ApiQuery extends ApiBase {
  43
  44         private $mPropModuleNames, $mListModuleNames, $mMetaModuleNames;
  45         private $mPageSet;
  46         private $params, $redirect;
  47
  48         private $mQueryPropModules = array (
  49                 'info' => 'ApiQueryInfo',
  50                 'revisions' => 'ApiQueryRevisions',
  51                 'links' => 'ApiQueryLinks',
  52                 'langlinks' => 'ApiQueryLangLinks',
  53                 'images' => 'ApiQueryImages',
  54                 'imageinfo' => 'ApiQueryImageInfo',
  55                 'templates' => 'ApiQueryLinks',
  56                 'categories' => 'ApiQueryCategories',
  57                 'extlinks' => 'ApiQueryExternalLinks',
  58                 'categoryinfo' => 'ApiQueryCategoryInfo',
  59         );
  60
  61         private $mQueryListModules = array (
  62                 'allimages' => 'ApiQueryAllimages',
  63                 'allpages' => 'ApiQueryAllpages',
  64                 'alllinks' => 'ApiQueryAllLinks',
  65                 'allcategories' => 'ApiQueryAllCategories',
  66                 'allusers' => 'ApiQueryAllUsers',
  67                 'backlinks' => 'ApiQueryBacklinks',
  68                 'blocks' => 'ApiQueryBlocks',
  69                 'categorymembers' => 'ApiQueryCategoryMembers',
  70                 'deletedrevs' => 'ApiQueryDeletedrevs',
  71                 'embeddedin' => 'ApiQueryBacklinks',
  72                 'imageusage' => 'ApiQueryBacklinks',
  73                 'logevents' => 'ApiQueryLogEvents',
  74                 'recentchanges' => 'ApiQueryRecentChanges',
  75                 'search' => 'ApiQuerySearch',
  76                 'usercontribs' => 'ApiQueryContributions',
  77                 'watchlist' => 'ApiQueryWatchlist',
  78                 'exturlusage' => 'ApiQueryExtLinksUsage',
  79                 'users' => 'ApiQueryUsers',
  80                 'random' => 'ApiQueryRandom',
  81         );
  82
  83         private $mQueryMetaModules = array (
  84                 'siteinfo' => 'ApiQuerySiteinfo',
  85                 'userinfo' => 'ApiQueryUserInfo',
  86                 'allmessages' => 'ApiQueryAllmessages',
  87         );
  88
  89         private $mSlaveDB = null;
  90         private $mNamedDB = array();
  91
  92         public function __construct($main, $action) {
  93                 parent :: __construct($main, $action);
  94
  95                 // Allow custom modules to be added in LocalSettings.php
  96                 global $wgApiQueryPropModules, $wgApiQueryListModules, $wgApiQueryMetaModules;
  97                 self :: appendUserModules($this->mQueryPropModules, $wgApiQueryPropModules);
  98                 self :: appendUserModules($this->mQueryListModules, $wgApiQueryListModules);
  99                 self :: appendUserModules($this->mQueryMetaModules, $wgApiQueryMetaModules);
 100
 101                 $this->mPropModuleNames = array_keys($this->mQueryPropModules);
 102                 $this->mListModuleNames = array_keys($this->mQueryListModules);
 103                 $this->mMetaModuleNames = array_keys($this->mQueryMetaModules);
 104
 105                 // Allow the entire list of modules at first,
 106                 // but during module instantiation check if it can be used as a generator.
 107                 $this->mAllowedGenerators = array_merge($this->mListModuleNames, $this->mPropModuleNames);
 108         }
 109
 110         /**
 111          * Helper function to append any add-in modules to the list
 112          */
 113         private static function appendUserModules(&$modules, $newModules) {
 114                 if (is_array( $newModules )) {
 115                         foreach ( $newModules as $moduleName => $moduleClass) {
 116                                 $modules[$moduleName] = $moduleClass;
 117                         }
 118                 }
 119         }
 120
 121         /**
 122          * Gets a default slave database connection object
 123          */
 124         public function getDB() {
 125                 if (!isset ($this->mSlaveDB)) {
 126                         $this->profileDBIn();
 127                         $this->mSlaveDB = wfGetDB(DB_SLAVE,'api');
 128                         $this->profileDBOut();
 129                 }
 130                 return $this->mSlaveDB;
 131         }
 132
 133         /**
 134          * Get the query database connection with the given name.
 135          * If no such connection has been requested before, it will be created.
 136          * Subsequent calls with the same $name will return the same connection
 137          * as the first, regardless of $db or $groups new values.
 138          */
 139         public function getNamedDB($name, $db, $groups) {
 140                 if (!array_key_exists($name, $this->mNamedDB)) {
 141                         $this->profileDBIn();
 142                         $this->mNamedDB[$name] = wfGetDB($db, $groups);
 143                         $this->profileDBOut();
 144                 }
 145                 return $this->mNamedDB[$name];
 146         }
 147
 148         /**
 149          * Gets the set of pages the user has requested (or generated)
 150          */
 151         public function getPageSet() {
 152                 return $this->mPageSet;
 153         }
 154
 155         /**
 156          * Get the array mapping module names to class names
 157          */
 158         function getModules() {
 159                 return array_merge($this->mQueryPropModules, $this->mQueryListModules, $this->mQueryMetaModules);
 160         }
 161
 162         /**
 163          * Query execution happens in the following steps:
 164          * #1 Create a PageSet object with any pages requested by the user
 165          * #2 If using generator, execute it to get a new PageSet object
 166          * #3 Instantiate all requested modules.
 167          *    This way the PageSet object will know what shared data is required,
 168          *    and minimize DB calls.
 169          * #4 Output all normalization and redirect resolution information
 170          * #5 Execute all requested modules
 171          */
 172         public function execute() {
 173
 174                 $this->params = $this->extractRequestParams();
 175                 $this->redirects = $this->params['redirects'];
 176
 177                 //
 178                 // Create PageSet
 179                 //
 180                 $this->mPageSet = new ApiPageSet($this, $this->redirects);
 181
 182                 //
 183                 // Instantiate requested modules
 184                 //
 185                 $modules = array ();
 186                 $this->InstantiateModules($modules, 'prop', $this->mQueryPropModules);
 187                 $this->InstantiateModules($modules, 'list', $this->mQueryListModules);
 188                 $this->InstantiateModules($modules, 'meta', $this->mQueryMetaModules);
 189
 190                 //
 191                 // If given, execute generator to substitute user supplied data with generated data.
 192                 //
 193                 if (isset ($this->params['generator'])) {
 194                         $this->executeGeneratorModule($this->params['generator'], $modules);
 195                 } else {
 196                         // Append custom fields and populate page/revision information
 197                         $this->addCustomFldsToPageSet($modules, $this->mPageSet);
 198                         $this->mPageSet->execute();
 199                 }
 200
 201                 //
 202                 // Record page information (title, namespace, if exists, etc)
 203                 //
 204                 $this->outputGeneralPageInfo();
 205
 206                 //
 207                 // Execute all requested modules.
 208                 //
 209                 foreach ($modules as $module) {
 210                         $module->profileIn();
 211                         $module->execute();
 212                         $module->profileOut();
 213                 }
 214         }
 215
 216         /**
 217          * Query modules may optimize data requests through the $this->getPageSet() object
 218          * by adding extra fields from the page table.
 219          * This function will gather all the extra request fields from the modules.
 220          */
 221         private function addCustomFldsToPageSet($modules, $pageSet) {
 222                 // Query all requested modules.
 223                 foreach ($modules as $module) {
 224                         $module->requestExtraData($pageSet);
 225                 }
 226         }
 227
 228         /**
 229          * Create instances of all modules requested by the client
 230          */
 231         private function InstantiateModules(&$modules, $param, $moduleList) {
 232                 $list = $this->params[$param];
 233                 if (isset ($list))
 234                         foreach ($list as $moduleName)
 235                                 $modules[] = new $moduleList[$moduleName] ($this, $moduleName);
 236         }
 237
 238         /**
 239          * Appends an element for each page in the current pageSet with the most general
 240          * information (id, title), plus any title normalizations and missing or invalid title/pageids/revids.
 241          */
 242         private function outputGeneralPageInfo() {
 243
 244                 $pageSet = $this->getPageSet();
 245                 $result = $this->getResult();
 246
 247                 // Title normalizations
 248                 $normValues = array ();
 249                 foreach ($pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr) {
 250                         $normValues[] = array (
 251                                 'from' => $rawTitleStr,
 252                                 'to' => $titleStr
 253                         );
 254                 }
 255
 256                 if (!empty ($normValues)) {
 257                         $result->setIndexedTagName($normValues, 'n');
 258                         $result->addValue('query', 'normalized', $normValues);
 259                 }
 260
 261                 // Interwiki titles
 262                 $intrwValues = array ();
 263                 foreach ($pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr) {
 264                         $intrwValues[] = array (
 265                                 'title' => $rawTitleStr,
 266                                 'iw' => $interwikiStr
 267                         );
 268                 }
 269
 270                 if (!empty ($intrwValues)) {
 271                         $result->setIndexedTagName($intrwValues, 'i');
 272                         $result->addValue('query', 'interwiki', $intrwValues);
 273                 }
 274
 275                 // Show redirect information
 276                 $redirValues = array ();
 277                 foreach ($pageSet->getRedirectTitles() as $titleStrFrom => $titleStrTo) {
 278                         $redirValues[] = array (
 279                                 'from' => strval($titleStrFrom),
 280                                 'to' => $titleStrTo
 281                         );
 282                 }
 283
 284                 if (!empty ($redirValues)) {
 285                         $result->setIndexedTagName($redirValues, 'r');
 286                         $result->addValue('query', 'redirects', $redirValues);
 287                 }
 288
 289                 //
 290                 // Missing revision elements
 291                 //
 292                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 293                 if (!empty ($missingRevIDs)) {
 294                         $revids = array ();
 295                         foreach ($missingRevIDs as $revid) {
 296                                 $revids[$revid] = array (
 297                                         'revid' => $revid
 298                                 );
 299                         }
 300                         $result->setIndexedTagName($revids, 'rev');
 301                         $result->addValue('query', 'badrevids', $revids);
 302                 }
 303
 304                 //
 305                 // Page elements
 306                 //
 307                 $pages = array ();
 308
 309                 // Report any missing titles
 310                 foreach ($pageSet->getMissingTitles() as $fakeId => $title) {
 311                         $vals = array();
 312                         ApiQueryBase :: addTitleInfo($vals, $title);
 313                         $vals['missing'] = '';
 314                         $pages[$fakeId] = $vals;
 315                 }
 316                 // Report any invalid titles
 317                 foreach ($pageSet->getInvalidTitles() as $fakeId => $title)
 318                         $pages[$fakeId] = array('title' => $title, 'invalid' => '');
 319                 // Report any missing page ids
 320                 foreach ($pageSet->getMissingPageIDs() as $pageid) {
 321                         $pages[$pageid] = array (
 322                                 'pageid' => $pageid,
 323                                 'missing' => ''
 324                         );
 325                 }
 326
 327                 // Output general page information for found titles
 328                 foreach ($pageSet->getGoodTitles() as $pageid => $title) {
 329                         $vals = array();
 330                         $vals['pageid'] = $pageid;
 331                         ApiQueryBase :: addTitleInfo($vals, $title);
 332                         $pages[$pageid] = $vals;
 333                 }
 334
 335                 if (!empty ($pages)) {
 336
 337                         if ($this->params['indexpageids']) {
 338                                 $pageIDs = array_keys($pages);
 339                                 // json treats all map keys as strings - converting to match
 340                                 $pageIDs = array_map('strval', $pageIDs);
 341                                 $result->setIndexedTagName($pageIDs, 'id');
 342                                 $result->addValue('query', 'pageids', $pageIDs);
 343                         }
 344
 345                         $result->setIndexedTagName($pages, 'page');
 346                         $result->addValue('query', 'pages', $pages);
 347                 }
 348         }
 349
 350         /**
 351          * For generator mode, execute generator, and use its output as new pageSet
 352          */
 353         protected function executeGeneratorModule($generatorName, $modules) {
 354
 355                 // Find class that implements requested generator
 356                 if (isset ($this->mQueryListModules[$generatorName])) {
 357                         $className = $this->mQueryListModules[$generatorName];
 358                 } elseif (isset ($this->mQueryPropModules[$generatorName])) {
 359                         $className = $this->mQueryPropModules[$generatorName];
 360                 } else {
 361                         ApiBase :: dieDebug(__METHOD__, "Unknown generator=$generatorName");
 362                 }
 363
 364                 // Generator results
 365                 $resultPageSet = new ApiPageSet($this, $this->redirects);
 366
 367                 // Create and execute the generator
 368                 $generator = new $className ($this, $generatorName);
 369                 if (!$generator instanceof ApiQueryGeneratorBase)
 370                         $this->dieUsage("Module $generatorName cannot be used as a generator", "badgenerator");
 371
 372                 $generator->setGeneratorMode();
 373
 374                 // Add any additional fields modules may need
 375                 $generator->requestExtraData($this->mPageSet);
 376                 $this->addCustomFldsToPageSet($modules, $resultPageSet);
 377
 378                 // Populate page information with the original user input
 379                 $this->mPageSet->execute();
 380
 381                 // populate resultPageSet with the generator output
 382                 $generator->profileIn();
 383                 $generator->executeGenerator($resultPageSet);
 384                 $resultPageSet->finishPageSetGeneration();
 385                 $generator->profileOut();
 386
 387                 // Swap the resulting pageset back in
 388                 $this->mPageSet = $resultPageSet;
 389         }
 390
 391         /**
 392          * Returns the list of allowed parameters for this module.
 393          * Qurey module also lists all ApiPageSet parameters as its own.
 394          */
 395         public function getAllowedParams() {
 396                 return array (
 397                         'prop' => array (
 398                                 ApiBase :: PARAM_ISMULTI => true,
 399                                 ApiBase :: PARAM_TYPE => $this->mPropModuleNames
 400                         ),
 401                         'list' => array (
 402                                 ApiBase :: PARAM_ISMULTI => true,
 403                                 ApiBase :: PARAM_TYPE => $this->mListModuleNames
 404                         ),
 405                         'meta' => array (
 406                                 ApiBase :: PARAM_ISMULTI => true,
 407                                 ApiBase :: PARAM_TYPE => $this->mMetaModuleNames
 408                         ),
 409                         'generator' => array (
 410                                 ApiBase :: PARAM_TYPE => $this->mAllowedGenerators
 411                         ),
 412                         'redirects' => false,
 413                         'indexpageids' => false,
 414                 );
 415         }
 416
 417         /**
 418          * Override the parent to generate help messages for all available query modules.
 419          */
 420         public function makeHelpMsg() {
 421
 422                 $msg = '';
 423
 424                 // Make sure the internal object is empty
 425                 // (just in case a sub-module decides to optimize during instantiation)
 426                 $this->mPageSet = null;
 427                 $this->mAllowedGenerators = array();    // Will be repopulated
 428
 429                 $astriks = str_repeat('--- ', 8);
 430                 $astriks2 = str_repeat('*** ', 10);
 431                 $msg .= "\n$astriks Query: Prop  $astriks\n\n";
 432                 $msg .= $this->makeHelpMsgHelper($this->mQueryPropModules, 'prop');
 433                 $msg .= "\n$astriks Query: List  $astriks\n\n";
 434                 $msg .= $this->makeHelpMsgHelper($this->mQueryListModules, 'list');
 435                 $msg .= "\n$astriks Query: Meta  $astriks\n\n";
 436                 $msg .= $this->makeHelpMsgHelper($this->mQueryMetaModules, 'meta');
 437                 $msg .= "\n\n$astriks2 Modules: continuation  $astriks2\n\n";
 438
 439                 // Perform the base call last because the $this->mAllowedGenerators
 440                 // will be updated inside makeHelpMsgHelper()
 441                 // Use parent to make default message for the query module
 442                 $msg = parent :: makeHelpMsg() . $msg;
 443
 444                 return $msg;
 445         }
 446
 447         /**
 448          * For all modules in $moduleList, generate help messages and join them together
 449          */
 450         private function makeHelpMsgHelper($moduleList, $paramName) {
 451
 452                 $moduleDscriptions = array ();
 453
 454                 foreach ($moduleList as $moduleName => $moduleClass) {
 455                         $module = new $moduleClass ($this, $moduleName, null);
 456
 457                         $msg = ApiMain::makeHelpMsgHeader($module, $paramName);
 458                         $msg2 = $module->makeHelpMsg();
 459                         if ($msg2 !== false)
 460                                 $msg .= $msg2;
 461                         if ($module instanceof ApiQueryGeneratorBase) {
 462                                 $this->mAllowedGenerators[] = $moduleName;
 463                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 464                         }
 465                         $moduleDscriptions[] = $msg;
 466                 }
 467
 468                 return implode("\n", $moduleDscriptions);
 469         }
 470
 471         /**
 472          * Override to add extra parameters from PageSet
 473          */
 474         public function makeHelpMsgParameters() {
 475                 $psModule = new ApiPageSet($this);
 476                 return $psModule->makeHelpMsgParameters() . parent :: makeHelpMsgParameters();
 477         }
 478
 479         // @todo should work correctly
 480         public function shouldCheckMaxlag() {
 481                 return true;
 482         }
 483
 484         public function getParamDescription() {
 485                 return array (
 486                         'prop' => 'Which properties to get for the titles/revisions/pageids',
 487                         'list' => 'Which lists to get',
 488                         'meta' => 'Which meta data to get about the site',
 489                         'generator' => 'Use the output of a list as the input for other prop/list/meta items',
 490                         'redirects' => 'Automatically resolve redirects',
 491                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs.'
 492                 );
 493         }
 494
 495         public function getDescription() {
 496                 return array (
 497                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 498                         'and is loosely based on the Query API interface currently available on all MediaWiki servers.',
 499                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites.'
 500                 );
 501         }
 502
 503         protected function getExamples() {
 504                 return array (
 505                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment'
 506                 );
 507         }
 508
 509         public function getVersion() {
 510                 $psModule = new ApiPageSet($this);
 511                 $vers = array ();
 512                 $vers[] = __CLASS__ . ': $Id$';
 513                 $vers[] = $psModule->getVersion();
 514                 return $vers;
 515         }
 516 }