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