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                 'templates' => 'ApiQueryLinks',
  55                 'categories' => 'ApiQueryCategories',
  56                 'extlinks' => 'ApiQueryExternalLinks',
  57         );
  58         //      'categories' => 'ApiQueryCategories',
  59         //      'imageinfo' => 'ApiQueryImageinfo',
  60         //      'templates' => 'ApiQueryTemplates',
  61
  62         private $mQueryListModules = array (
  63                 'allpages' => 'ApiQueryAllpages',
  64                 'backlinks' => 'ApiQueryBacklinks',
  65                 'categorymembers' => 'ApiQueryCategoryMembers',
  66                 'embeddedin' => 'ApiQueryBacklinks',
  67                 'imageusage' => 'ApiQueryBacklinks',
  68                 'logevents' => 'ApiQueryLogEvents',
  69                 'recentchanges' => 'ApiQueryRecentChanges',
  70                 'usercontribs' => 'ApiQueryContributions',
  71                 'watchlist' => 'ApiQueryWatchlist',
  72         );
  73         //      'recentchanges' => 'ApiQueryRecentchanges',
  74         //      'users' => 'ApiQueryUsers',
  75         //      'watchlist' => 'ApiQueryWatchlist',
  76
  77         private $mQueryMetaModules = array (
  78                 'siteinfo' => 'ApiQuerySiteinfo'
  79         );
  80         //      'userinfo' => 'ApiQueryUserinfo',
  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                 $fakepageid = -1;
 297                 foreach ($pageSet->getMissingTitles() as $title) {
 298                         $vals = array();
 299                         ApiQueryBase :: addTitleInfo($vals, $title, true);
 300                         $vals['missing'] = '';
 301                         $pages[$fakepageid--] = $vals;
 302                 }
 303
 304                 // Report any missing page ids
 305                 foreach ($pageSet->getMissingPageIDs() as $pageid) {
 306                         $pages[$pageid] = array (
 307                                 'pageid' => $pageid,
 308                                 'missing' => ''
 309                         );
 310                 }
 311
 312                 // Output general page information for found titles
 313                 foreach ($pageSet->getGoodTitles() as $pageid => $title) {
 314                         $vals = array();
 315                         $vals['pageid'] = $pageid;
 316                         ApiQueryBase :: addTitleInfo($vals, $title, true);
 317                         $pages[$pageid] = $vals;
 318                 }
 319
 320                 if (!empty ($pages)) {
 321
 322                         if ($this->params['indexpageids']) {
 323                                 $pageIDs = array_keys($pages);
 324                                 // json treats all map keys as strings - converting to match
 325                                 $pageIDs = array_map('strval', $pageIDs);
 326                                 $result->setIndexedTagName($pageIDs, 'id');
 327                                 $result->addValue('query', 'pageids', $pageIDs);
 328                         }
 329
 330                         $result->setIndexedTagName($pages, 'page');
 331                         $result->addValue('query', 'pages', $pages);
 332                 }
 333         }
 334
 335         /**
 336          * For generator mode, execute generator, and use its output as new pageSet
 337          */
 338         protected function executeGeneratorModule($generatorName, $modules) {
 339
 340                 // Find class that implements requested generator
 341                 if (isset ($this->mQueryListModules[$generatorName])) {
 342                         $className = $this->mQueryListModules[$generatorName];
 343                 } elseif (isset ($this->mQueryPropModules[$generatorName])) {
 344                         $className = $this->mQueryPropModules[$generatorName];
 345                 } else {
 346                         ApiBase :: dieDebug(__METHOD__, "Unknown generator=$generatorName");
 347                 }
 348
 349                 // Generator results
 350                 $resultPageSet = new ApiPageSet($this, $this->redirects);
 351
 352                 // Create and execute the generator
 353                 $generator = new $className ($this, $generatorName);
 354                 if (!$generator instanceof ApiQueryGeneratorBase)
 355                         $this->dieUsage("Module $generatorName cannot be used as a generator", "badgenerator");
 356
 357                 $generator->setGeneratorMode();
 358
 359                 // Add any additional fields modules may need
 360                 $generator->requestExtraData($this->mPageSet);
 361                 $this->addCustomFldsToPageSet($modules, $resultPageSet);
 362
 363                 // Populate page information with the original user input
 364                 $this->mPageSet->execute();
 365
 366                 // populate resultPageSet with the generator output
 367                 $generator->profileIn();
 368                 $generator->executeGenerator($resultPageSet);
 369                 $resultPageSet->finishPageSetGeneration();
 370                 $generator->profileOut();
 371
 372                 // Swap the resulting pageset back in
 373                 $this->mPageSet = $resultPageSet;
 374         }
 375
 376         /**
 377          * Returns the list of allowed parameters for this module.
 378          * Qurey module also lists all ApiPageSet parameters as its own.
 379          */
 380         protected function getAllowedParams() {
 381                 return array (
 382                         'prop' => array (
 383                                 ApiBase :: PARAM_ISMULTI => true,
 384                                 ApiBase :: PARAM_TYPE => $this->mPropModuleNames
 385                         ),
 386                         'list' => array (
 387                                 ApiBase :: PARAM_ISMULTI => true,
 388                                 ApiBase :: PARAM_TYPE => $this->mListModuleNames
 389                         ),
 390                         'meta' => array (
 391                                 ApiBase :: PARAM_ISMULTI => true,
 392                                 ApiBase :: PARAM_TYPE => $this->mMetaModuleNames
 393                         ),
 394                         'generator' => array (
 395                                 ApiBase :: PARAM_TYPE => $this->mAllowedGenerators
 396                         ),
 397                         'redirects' => false,
 398                         'indexpageids' => false,
 399                 );
 400         }
 401
 402         /**
 403          * Override the parent to generate help messages for all available query modules.
 404          */
 405         public function makeHelpMsg() {
 406
 407                 $msg = '';
 408
 409                 // Make sure the internal object is empty
 410                 // (just in case a sub-module decides to optimize during instantiation)
 411                 $this->mPageSet = null;
 412                 $this->mAllowedGenerators = array();    // Will be repopulated
 413
 414                 $astriks = str_repeat('--- ', 8);
 415                 $msg .= "\n$astriks Query: Prop  $astriks\n\n";
 416                 $msg .= $this->makeHelpMsgHelper($this->mQueryPropModules, 'prop');
 417                 $msg .= "\n$astriks Query: List  $astriks\n\n";
 418                 $msg .= $this->makeHelpMsgHelper($this->mQueryListModules, 'list');
 419                 $msg .= "\n$astriks Query: Meta  $astriks\n\n";
 420                 $msg .= $this->makeHelpMsgHelper($this->mQueryMetaModules, 'meta');
 421
 422                 // Perform the base call last because the $this->mAllowedGenerators
 423                 // will be updated inside makeHelpMsgHelper()
 424                 // Use parent to make default message for the query module
 425                 $msg = parent :: makeHelpMsg() . $msg;
 426
 427                 return $msg;
 428         }
 429
 430         /**
 431          * For all modules in $moduleList, generate help messages and join them together
 432          */
 433         private function makeHelpMsgHelper($moduleList, $paramName) {
 434
 435                 $moduleDscriptions = array ();
 436
 437                 foreach ($moduleList as $moduleName => $moduleClass) {
 438                         $module = new $moduleClass ($this, $moduleName, null);
 439
 440                         $msg = ApiMain::makeHelpMsgHeader($module, $paramName);
 441                         $msg2 = $module->makeHelpMsg();
 442                         if ($msg2 !== false)
 443                                 $msg .= $msg2;
 444                         if ($module instanceof ApiQueryGeneratorBase) {
 445                                 $this->mAllowedGenerators[] = $moduleName;
 446                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 447                         }
 448                         $moduleDscriptions[] = $msg;
 449                 }
 450
 451                 return implode("\n", $moduleDscriptions);
 452         }
 453
 454         /**
 455          * Override to add extra parameters from PageSet
 456          */
 457         public function makeHelpMsgParameters() {
 458                 $psModule = new ApiPageSet($this);
 459                 return $psModule->makeHelpMsgParameters() . parent :: makeHelpMsgParameters();
 460         }
 461
 462         protected function getParamDescription() {
 463                 return array (
 464                         'prop' => 'Which properties to get for the titles/revisions/pageids',
 465                         'list' => 'Which lists to get',
 466                         'meta' => 'Which meta data to get about the site',
 467                         'generator' => 'Use the output of a list as the input for other prop/list/meta items',
 468                         'redirects' => 'Automatically resolve redirects',
 469                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs.'
 470                 );
 471         }
 472
 473         protected function getDescription() {
 474                 return array (
 475                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 476                         'and is loosely based on the Query API interface currently available on all MediaWiki servers.',
 477                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites.'
 478                 );
 479         }
 480
 481         protected function getExamples() {
 482                 return array (
 483                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment'
 484                 );
 485         }
 486
 487         public function getVersion() {
 488                 $psModule = new ApiPageSet($this);
 489                 $vers = array ();
 490                 $vers[] = __CLASS__ . ': $Id$';
 491                 $vers[] = $psModule->getVersion();
 492                 return $vers;
 493         }
 494 }
 495 ?>