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