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