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