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 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' => $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] = $vals;
 314                 }
 315
 316                 // Report any missing page ids
 317                 foreach ($pageSet->getMissingPageIDs() as $pageid) {
 318                         $pages[$pageid] = array (
 319                                 'pageid' => $pageid,
 320                                 'missing' => ''
 321                         );
 322                 }
 323
 324                 // Output general page information for found titles
 325                 foreach ($pageSet->getGoodTitles() as $pageid => $title) {
 326                         $vals = array();
 327                         $vals['pageid'] = $pageid;
 328                         ApiQueryBase :: addTitleInfo($vals, $title);
 329                         $pages[$pageid] = $vals;
 330                 }
 331
 332                 if (!empty ($pages)) {
 333
 334                         if ($this->params['indexpageids']) {
 335                                 $pageIDs = array_keys($pages);
 336                                 // json treats all map keys as strings - converting to match
 337                                 $pageIDs = array_map('strval', $pageIDs);
 338                                 $result->setIndexedTagName($pageIDs, 'id');
 339                                 $result->addValue('query', 'pageids', $pageIDs);
 340                         }
 341
 342                         $result->setIndexedTagName($pages, 'page');
 343                         $result->addValue('query', 'pages', $pages);
 344                 }
 345         }
 346
 347         /**
 348          * For generator mode, execute generator, and use its output as new pageSet
 349          */
 350         protected function executeGeneratorModule($generatorName, $modules) {
 351
 352                 // Find class that implements requested generator
 353                 if (isset ($this->mQueryListModules[$generatorName])) {
 354                         $className = $this->mQueryListModules[$generatorName];
 355                 } elseif (isset ($this->mQueryPropModules[$generatorName])) {
 356                         $className = $this->mQueryPropModules[$generatorName];
 357                 } else {
 358                         ApiBase :: dieDebug(__METHOD__, "Unknown generator=$generatorName");
 359                 }
 360
 361                 // Generator results
 362                 $resultPageSet = new ApiPageSet($this, $this->redirects);
 363
 364                 // Create and execute the generator
 365                 $generator = new $className ($this, $generatorName);
 366                 if (!$generator instanceof ApiQueryGeneratorBase)
 367                         $this->dieUsage("Module $generatorName cannot be used as a generator", "badgenerator");
 368
 369                 $generator->setGeneratorMode();
 370
 371                 // Add any additional fields modules may need
 372                 $generator->requestExtraData($this->mPageSet);
 373                 $this->addCustomFldsToPageSet($modules, $resultPageSet);
 374
 375                 // Populate page information with the original user input
 376                 $this->mPageSet->execute();
 377
 378                 // populate resultPageSet with the generator output
 379                 $generator->profileIn();
 380                 $generator->executeGenerator($resultPageSet);
 381                 $resultPageSet->finishPageSetGeneration();
 382                 $generator->profileOut();
 383
 384                 // Swap the resulting pageset back in
 385                 $this->mPageSet = $resultPageSet;
 386         }
 387
 388         /**
 389          * Returns the list of allowed parameters for this module.
 390          * Qurey module also lists all ApiPageSet parameters as its own.
 391          */
 392         public function getAllowedParams() {
 393                 return array (
 394                         'prop' => array (
 395                                 ApiBase :: PARAM_ISMULTI => true,
 396                                 ApiBase :: PARAM_TYPE => $this->mPropModuleNames
 397                         ),
 398                         'list' => array (
 399                                 ApiBase :: PARAM_ISMULTI => true,
 400                                 ApiBase :: PARAM_TYPE => $this->mListModuleNames
 401                         ),
 402                         'meta' => array (
 403                                 ApiBase :: PARAM_ISMULTI => true,
 404                                 ApiBase :: PARAM_TYPE => $this->mMetaModuleNames
 405                         ),
 406                         'generator' => array (
 407                                 ApiBase :: PARAM_TYPE => $this->mAllowedGenerators
 408                         ),
 409                         'redirects' => false,
 410                         'indexpageids' => false,
 411                 );
 412         }
 413
 414         /**
 415          * Override the parent to generate help messages for all available query modules.
 416          */
 417         public function makeHelpMsg() {
 418
 419                 $msg = '';
 420
 421                 // Make sure the internal object is empty
 422                 // (just in case a sub-module decides to optimize during instantiation)
 423                 $this->mPageSet = null;
 424                 $this->mAllowedGenerators = array();    // Will be repopulated
 425
 426                 $astriks = str_repeat('--- ', 8);
 427                 $astriks2 = str_repeat('*** ', 10);
 428                 $msg .= "\n$astriks Query: Prop  $astriks\n\n";
 429                 $msg .= $this->makeHelpMsgHelper($this->mQueryPropModules, 'prop');
 430                 $msg .= "\n$astriks Query: List  $astriks\n\n";
 431                 $msg .= $this->makeHelpMsgHelper($this->mQueryListModules, 'list');
 432                 $msg .= "\n$astriks Query: Meta  $astriks\n\n";
 433                 $msg .= $this->makeHelpMsgHelper($this->mQueryMetaModules, 'meta');
 434                 $msg .= "\n\n$astriks2 Modules: continuation  $astriks2\n\n";
 435
 436                 // Perform the base call last because the $this->mAllowedGenerators
 437                 // will be updated inside makeHelpMsgHelper()
 438                 // Use parent to make default message for the query module
 439                 $msg = parent :: makeHelpMsg() . $msg;
 440
 441                 return $msg;
 442         }
 443
 444         /**
 445          * For all modules in $moduleList, generate help messages and join them together
 446          */
 447         private function makeHelpMsgHelper($moduleList, $paramName) {
 448
 449                 $moduleDscriptions = array ();
 450
 451                 foreach ($moduleList as $moduleName => $moduleClass) {
 452                         $module = new $moduleClass ($this, $moduleName, null);
 453
 454                         $msg = ApiMain::makeHelpMsgHeader($module, $paramName);
 455                         $msg2 = $module->makeHelpMsg();
 456                         if ($msg2 !== false)
 457                                 $msg .= $msg2;
 458                         if ($module instanceof ApiQueryGeneratorBase) {
 459                                 $this->mAllowedGenerators[] = $moduleName;
 460                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 461                         }
 462                         $moduleDscriptions[] = $msg;
 463                 }
 464
 465                 return implode("\n", $moduleDscriptions);
 466         }
 467
 468         /**
 469          * Override to add extra parameters from PageSet
 470          */
 471         public function makeHelpMsgParameters() {
 472                 $psModule = new ApiPageSet($this);
 473                 return $psModule->makeHelpMsgParameters() . parent :: makeHelpMsgParameters();
 474         }
 475
 476         // @todo should work correctly
 477         public function shouldCheckMaxlag() {
 478                 return true;
 479         }
 480
 481         public function getParamDescription() {
 482                 return array (
 483                         'prop' => 'Which properties to get for the titles/revisions/pageids',
 484                         'list' => 'Which lists to get',
 485                         'meta' => 'Which meta data to get about the site',
 486                         'generator' => 'Use the output of a list as the input for other prop/list/meta items',
 487                         'redirects' => 'Automatically resolve redirects',
 488                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs.'
 489                 );
 490         }
 491
 492         public function getDescription() {
 493                 return array (
 494                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 495                         'and is loosely based on the Query API interface currently available on all MediaWiki servers.',
 496                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites.'
 497                 );
 498         }
 499
 500         protected function getExamples() {
 501                 return array (
 502                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment'
 503                 );
 504         }
 505
 506         public function getVersion() {
 507                 $psModule = new ApiPageSet($this);
 508                 $vers = array ();
 509                 $vers[] = __CLASS__ . ': $Id$';
 510                 $vers[] = $psModule->getVersion();
 511                 return $vers;
 512         }
 513 }
 514