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