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  * @ingroup 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                 'duplicatefiles' => 'ApiQueryDuplicateFiles',
  60         );
  61
  62         private $mQueryListModules = array (
  63                 'allimages' => 'ApiQueryAllimages',
  64                 'allpages' => 'ApiQueryAllpages',
  65                 'alllinks' => 'ApiQueryAllLinks',
  66                 'allcategories' => 'ApiQueryAllCategories',
  67                 'allusers' => 'ApiQueryAllUsers',
  68                 'backlinks' => 'ApiQueryBacklinks',
  69                 'blocks' => 'ApiQueryBlocks',
  70                 'categorymembers' => 'ApiQueryCategoryMembers',
  71                 'deletedrevs' => 'ApiQueryDeletedrevs',
  72                 'embeddedin' => 'ApiQueryBacklinks',
  73                 'imageusage' => 'ApiQueryBacklinks',
  74                 'logevents' => 'ApiQueryLogEvents',
  75                 'recentchanges' => 'ApiQueryRecentChanges',
  76                 'search' => 'ApiQuerySearch',
  77                 'usercontribs' => 'ApiQueryContributions',
  78                 'watchlist' => 'ApiQueryWatchlist',
  79                 'watchlistraw' => 'ApiQueryWatchlistRaw',
  80                 'exturlusage' => 'ApiQueryExtLinksUsage',
  81                 'users' => 'ApiQueryUsers',
  82                 'random' => 'ApiQueryRandom',
  83         );
  84
  85         private $mQueryMetaModules = array (
  86                 'siteinfo' => 'ApiQuerySiteinfo',
  87                 'userinfo' => 'ApiQueryUserInfo',
  88                 'allmessages' => 'ApiQueryAllmessages',
  89         );
  90
  91         private $mSlaveDB = null;
  92         private $mNamedDB = array();
  93
  94         public function __construct($main, $action) {
  95                 parent :: __construct($main, $action);
  96
  97                 // Allow custom modules to be added in LocalSettings.php
  98                 global $wgAPIPropModules, $wgAPIListModules, $wgAPIMetaModules;
  99                 self :: appendUserModules($this->mQueryPropModules, $wgAPIPropModules);
 100                 self :: appendUserModules($this->mQueryListModules, $wgAPIListModules);
 101                 self :: appendUserModules($this->mQueryMetaModules, $wgAPIMetaModules);
 102
 103                 $this->mPropModuleNames = array_keys($this->mQueryPropModules);
 104                 $this->mListModuleNames = array_keys($this->mQueryListModules);
 105                 $this->mMetaModuleNames = array_keys($this->mQueryMetaModules);
 106
 107                 // Allow the entire list of modules at first,
 108                 // but during module instantiation check if it can be used as a generator.
 109                 $this->mAllowedGenerators = array_merge($this->mListModuleNames, $this->mPropModuleNames);
 110         }
 111
 112         /**
 113          * Helper function to append any add-in modules to the list
 114          */
 115         private static function appendUserModules(&$modules, $newModules) {
 116                 if (is_array( $newModules )) {
 117                         foreach ( $newModules as $moduleName => $moduleClass) {
 118                                 $modules[$moduleName] = $moduleClass;
 119                         }
 120                 }
 121         }
 122
 123         /**
 124          * Gets a default slave database connection object
 125          */
 126         public function getDB() {
 127                 if (!isset ($this->mSlaveDB)) {
 128                         $this->profileDBIn();
 129                         $this->mSlaveDB = wfGetDB(DB_SLAVE,'api');
 130                         $this->profileDBOut();
 131                 }
 132                 return $this->mSlaveDB;
 133         }
 134
 135         /**
 136          * Get the query database connection with the given name.
 137          * If no such connection has been requested before, it will be created.
 138          * Subsequent calls with the same $name will return the same connection
 139          * as the first, regardless of $db or $groups new values.
 140          */
 141         public function getNamedDB($name, $db, $groups) {
 142                 if (!array_key_exists($name, $this->mNamedDB)) {
 143                         $this->profileDBIn();
 144                         $this->mNamedDB[$name] = wfGetDB($db, $groups);
 145                         $this->profileDBOut();
 146                 }
 147                 return $this->mNamedDB[$name];
 148         }
 149
 150         /**
 151          * Gets the set of pages the user has requested (or generated)
 152          */
 153         public function getPageSet() {
 154                 return $this->mPageSet;
 155         }
 156
 157         /**
 158          * Get the array mapping module names to class names
 159          */
 160         function getModules() {
 161                 return array_merge($this->mQueryPropModules, $this->mQueryListModules, $this->mQueryMetaModules);
 162         }
 163
 164         /**
 165          * Query execution happens in the following steps:
 166          * #1 Create a PageSet object with any pages requested by the user
 167          * #2 If using generator, execute it to get a new PageSet object
 168          * #3 Instantiate all requested modules.
 169          *    This way the PageSet object will know what shared data is required,
 170          *    and minimize DB calls.
 171          * #4 Output all normalization and redirect resolution information
 172          * #5 Execute all requested modules
 173          */
 174         public function execute() {
 175
 176                 $this->params = $this->extractRequestParams();
 177                 $this->redirects = $this->params['redirects'];
 178
 179                 //
 180                 // Create PageSet
 181                 //
 182                 $this->mPageSet = new ApiPageSet($this, $this->redirects);
 183
 184                 //
 185                 // Instantiate requested modules
 186                 //
 187                 $modules = array ();
 188                 $this->InstantiateModules($modules, 'prop', $this->mQueryPropModules);
 189                 $this->InstantiateModules($modules, 'list', $this->mQueryListModules);
 190                 $this->InstantiateModules($modules, 'meta', $this->mQueryMetaModules);
 191
 192                 //
 193                 // If given, execute generator to substitute user supplied data with generated data.
 194                 //
 195                 if (isset ($this->params['generator'])) {
 196                         $this->executeGeneratorModule($this->params['generator'], $modules);
 197                 } else {
 198                         // Append custom fields and populate page/revision information
 199                         $this->addCustomFldsToPageSet($modules, $this->mPageSet);
 200                         $this->mPageSet->execute();
 201                 }
 202
 203                 //
 204                 // Record page information (title, namespace, if exists, etc)
 205                 //
 206                 $this->outputGeneralPageInfo();
 207
 208                 //
 209                 // Execute all requested modules.
 210                 //
 211                 foreach ($modules as $module) {
 212                         $module->profileIn();
 213                         $module->execute();
 214                         wfRunHooks('APIQueryAfterExecute', array(&$module));
 215                         $module->profileOut();
 216                 }
 217         }
 218
 219         /**
 220          * Query modules may optimize data requests through the $this->getPageSet() object
 221          * by adding extra fields from the page table.
 222          * This function will gather all the extra request fields from the modules.
 223          */
 224         private function addCustomFldsToPageSet($modules, $pageSet) {
 225                 // Query all requested modules.
 226                 foreach ($modules as $module) {
 227                         $module->requestExtraData($pageSet);
 228                 }
 229         }
 230
 231         /**
 232          * Create instances of all modules requested by the client
 233          */
 234         private function InstantiateModules(&$modules, $param, $moduleList) {
 235                 $list = @$this->params[$param];
 236                 if (!is_null ($list))
 237                         foreach ($list as $moduleName)
 238                                 $modules[] = new $moduleList[$moduleName] ($this, $moduleName);
 239         }
 240
 241         /**
 242          * Appends an element for each page in the current pageSet with the most general
 243          * information (id, title), plus any title normalizations and missing or invalid title/pageids/revids.
 244          */
 245         private function outputGeneralPageInfo() {
 246
 247                 $pageSet = $this->getPageSet();
 248                 $result = $this->getResult();
 249
 250                 // Title normalizations
 251                 $normValues = array ();
 252                 foreach ($pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr) {
 253                         $normValues[] = array (
 254                                 'from' => $rawTitleStr,
 255                                 'to' => $titleStr
 256                         );
 257                 }
 258
 259                 if (!empty ($normValues)) {
 260                         $result->setIndexedTagName($normValues, 'n');
 261                         $result->addValue('query', 'normalized', $normValues);
 262                 }
 263
 264                 // Interwiki titles
 265                 $intrwValues = array ();
 266                 foreach ($pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr) {
 267                         $intrwValues[] = array (
 268                                 'title' => $rawTitleStr,
 269                                 'iw' => $interwikiStr
 270                         );
 271                 }
 272
 273                 if (!empty ($intrwValues)) {
 274                         $result->setIndexedTagName($intrwValues, 'i');
 275                         $result->addValue('query', 'interwiki', $intrwValues);
 276                 }
 277
 278                 // Show redirect information
 279                 $redirValues = array ();
 280                 foreach ($pageSet->getRedirectTitles() as $titleStrFrom => $titleStrTo) {
 281                         $redirValues[] = array (
 282                                 'from' => strval($titleStrFrom),
 283                                 'to' => $titleStrTo
 284                         );
 285                 }
 286
 287                 if (!empty ($redirValues)) {
 288                         $result->setIndexedTagName($redirValues, 'r');
 289                         $result->addValue('query', 'redirects', $redirValues);
 290                 }
 291
 292                 //
 293                 // Missing revision elements
 294                 //
 295                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 296                 if (!empty ($missingRevIDs)) {
 297                         $revids = array ();
 298                         foreach ($missingRevIDs as $revid) {
 299                                 $revids[$revid] = array (
 300                                         'revid' => $revid
 301                                 );
 302                         }
 303                         $result->setIndexedTagName($revids, 'rev');
 304                         $result->addValue('query', 'badrevids', $revids);
 305                 }
 306
 307                 //
 308                 // Page elements
 309                 //
 310                 $pages = array ();
 311
 312                 // Report any missing titles
 313                 foreach ($pageSet->getMissingTitles() as $fakeId => $title) {
 314                         $vals = array();
 315                         ApiQueryBase :: addTitleInfo($vals, $title);
 316                         $vals['missing'] = '';
 317                         $pages[$fakeId] = $vals;
 318                 }
 319                 // Report any invalid titles
 320                 foreach ($pageSet->getInvalidTitles() as $fakeId => $title)
 321                         $pages[$fakeId] = array('title' => $title, 'invalid' => '');
 322                 // Report any missing page ids
 323                 foreach ($pageSet->getMissingPageIDs() as $pageid) {
 324                         $pages[$pageid] = array (
 325                                 'pageid' => $pageid,
 326                                 'missing' => ''
 327                         );
 328                 }
 329
 330                 // Output general page information for found titles
 331                 foreach ($pageSet->getGoodTitles() as $pageid => $title) {
 332                         $vals = array();
 333                         $vals['pageid'] = $pageid;
 334                         ApiQueryBase :: addTitleInfo($vals, $title);
 335                         $pages[$pageid] = $vals;
 336                 }
 337
 338                 if (!empty ($pages)) {
 339
 340                         if ($this->params['indexpageids']) {
 341                                 $pageIDs = array_keys($pages);
 342                                 // json treats all map keys as strings - converting to match
 343                                 $pageIDs = array_map('strval', $pageIDs);
 344                                 $result->setIndexedTagName($pageIDs, 'id');
 345                                 $result->addValue('query', 'pageids', $pageIDs);
 346                         }
 347
 348                         $result->setIndexedTagName($pages, 'page');
 349                         $result->addValue('query', 'pages', $pages);
 350                 }
 351         }
 352
 353         /**
 354          * For generator mode, execute generator, and use its output as new pageSet
 355          */
 356         protected function executeGeneratorModule($generatorName, $modules) {
 357
 358                 // Find class that implements requested generator
 359                 if (isset ($this->mQueryListModules[$generatorName])) {
 360                         $className = $this->mQueryListModules[$generatorName];
 361                 } elseif (isset ($this->mQueryPropModules[$generatorName])) {
 362                         $className = $this->mQueryPropModules[$generatorName];
 363                 } else {
 364                         ApiBase :: dieDebug(__METHOD__, "Unknown generator=$generatorName");
 365                 }
 366
 367                 // Generator results
 368                 $resultPageSet = new ApiPageSet($this, $this->redirects);
 369
 370                 // Create and execute the generator
 371                 $generator = new $className ($this, $generatorName);
 372                 if (!$generator instanceof ApiQueryGeneratorBase)
 373                         $this->dieUsage("Module $generatorName cannot be used as a generator", "badgenerator");
 374
 375                 $generator->setGeneratorMode();
 376
 377                 // Add any additional fields modules may need
 378                 $generator->requestExtraData($this->mPageSet);
 379                 $this->addCustomFldsToPageSet($modules, $resultPageSet);
 380
 381                 // Populate page information with the original user input
 382                 $this->mPageSet->execute();
 383
 384                 // populate resultPageSet with the generator output
 385                 $generator->profileIn();
 386                 $generator->executeGenerator($resultPageSet);
 387                 wfRunHooks('APIQueryGeneratorAfterExecute', array(&$generator, &$resultPageSet));
 388                 $resultPageSet->finishPageSetGeneration();
 389                 $generator->profileOut();
 390
 391                 // Swap the resulting pageset back in
 392                 $this->mPageSet = $resultPageSet;
 393         }
 394
 395         /**
 396          * Returns the list of allowed parameters for this module.
 397          * Qurey module also lists all ApiPageSet parameters as its own.
 398          */
 399         public function getAllowedParams() {
 400                 return array (
 401                         'prop' => array (
 402                                 ApiBase :: PARAM_ISMULTI => true,
 403                                 ApiBase :: PARAM_TYPE => $this->mPropModuleNames
 404                         ),
 405                         'list' => array (
 406                                 ApiBase :: PARAM_ISMULTI => true,
 407                                 ApiBase :: PARAM_TYPE => $this->mListModuleNames
 408                         ),
 409                         'meta' => array (
 410                                 ApiBase :: PARAM_ISMULTI => true,
 411                                 ApiBase :: PARAM_TYPE => $this->mMetaModuleNames
 412                         ),
 413                         'generator' => array (
 414                                 ApiBase :: PARAM_TYPE => $this->mAllowedGenerators
 415                         ),
 416                         'redirects' => false,
 417                         'indexpageids' => false,
 418                 );
 419         }
 420
 421         /**
 422          * Override the parent to generate help messages for all available query modules.
 423          */
 424         public function makeHelpMsg() {
 425
 426                 $msg = '';
 427
 428                 // Make sure the internal object is empty
 429                 // (just in case a sub-module decides to optimize during instantiation)
 430                 $this->mPageSet = null;
 431                 $this->mAllowedGenerators = array();    // Will be repopulated
 432
 433                 $astriks = str_repeat('--- ', 8);
 434                 $astriks2 = str_repeat('*** ', 10);
 435                 $msg .= "\n$astriks Query: Prop  $astriks\n\n";
 436                 $msg .= $this->makeHelpMsgHelper($this->mQueryPropModules, 'prop');
 437                 $msg .= "\n$astriks Query: List  $astriks\n\n";
 438                 $msg .= $this->makeHelpMsgHelper($this->mQueryListModules, 'list');
 439                 $msg .= "\n$astriks Query: Meta  $astriks\n\n";
 440                 $msg .= $this->makeHelpMsgHelper($this->mQueryMetaModules, 'meta');
 441                 $msg .= "\n\n$astriks2 Modules: continuation  $astriks2\n\n";
 442
 443                 // Perform the base call last because the $this->mAllowedGenerators
 444                 // will be updated inside makeHelpMsgHelper()
 445                 // Use parent to make default message for the query module
 446                 $msg = parent :: makeHelpMsg() . $msg;
 447
 448                 return $msg;
 449         }
 450
 451         /**
 452          * For all modules in $moduleList, generate help messages and join them together
 453          */
 454         private function makeHelpMsgHelper($moduleList, $paramName) {
 455
 456                 $moduleDscriptions = array ();
 457
 458                 foreach ($moduleList as $moduleName => $moduleClass) {
 459                         $module = new $moduleClass ($this, $moduleName, null);
 460
 461                         $msg = ApiMain::makeHelpMsgHeader($module, $paramName);
 462                         $msg2 = $module->makeHelpMsg();
 463                         if ($msg2 !== false)
 464                                 $msg .= $msg2;
 465                         if ($module instanceof ApiQueryGeneratorBase) {
 466                                 $this->mAllowedGenerators[] = $moduleName;
 467                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 468                         }
 469                         $moduleDscriptions[] = $msg;
 470                 }
 471
 472                 return implode("\n", $moduleDscriptions);
 473         }
 474
 475         /**
 476          * Override to add extra parameters from PageSet
 477          */
 478         public function makeHelpMsgParameters() {
 479                 $psModule = new ApiPageSet($this);
 480                 return $psModule->makeHelpMsgParameters() . parent :: makeHelpMsgParameters();
 481         }
 482
 483         public function shouldCheckMaxlag() {
 484                 return true;
 485         }
 486
 487         public function getParamDescription() {
 488                 return array (
 489                         'prop' => 'Which properties to get for the titles/revisions/pageids',
 490                         'list' => 'Which lists to get',
 491                         'meta' => 'Which meta data to get about the site',
 492                         'generator' => 'Use the output of a list as the input for other prop/list/meta items',
 493                         'redirects' => 'Automatically resolve redirects',
 494                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs.'
 495                 );
 496         }
 497
 498         public function getDescription() {
 499                 return array (
 500                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 501                         'and is loosely based on the Query API interface currently available on all MediaWiki servers.',
 502                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites.'
 503                 );
 504         }
 505
 506         protected function getExamples() {
 507                 return array (
 508                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment'
 509                 );
 510         }
 511
 512         public function getVersion() {
 513                 $psModule = new ApiPageSet($this);
 514                 $vers = array ();
 515                 $vers[] = __CLASS__ . ': $Id$';
 516                 $vers[] = $psModule->getVersion();
 517                 return $vers;
 518         }
 519 }