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  * @ingroup 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                 'categoryinfo' => 'ApiQueryCategoryInfo',
  59         );
  60
  61         private $mQueryListModules = array (
  62                 'allimages' => 'ApiQueryAllimages',
  63                 'allpages' => 'ApiQueryAllpages',
  64                 'alllinks' => 'ApiQueryAllLinks',
  65                 'allcategories' => 'ApiQueryAllCategories',
  66                 'allusers' => 'ApiQueryAllUsers',
  67                 'backlinks' => 'ApiQueryBacklinks',
  68                 'blocks' => 'ApiQueryBlocks',
  69                 'categorymembers' => 'ApiQueryCategoryMembers',
  70                 'deletedrevs' => 'ApiQueryDeletedrevs',
  71                 'embeddedin' => 'ApiQueryBacklinks',
  72                 'imageusage' => 'ApiQueryBacklinks',
  73                 'logevents' => 'ApiQueryLogEvents',
  74                 'recentchanges' => 'ApiQueryRecentChanges',
  75                 'search' => 'ApiQuerySearch',
  76                 'usercontribs' => 'ApiQueryContributions',
  77                 'watchlist' => 'ApiQueryWatchlist',
  78                 'exturlusage' => 'ApiQueryExtLinksUsage',
  79                 'users' => 'ApiQueryUsers',
  80                 'random' => 'ApiQueryRandom',
  81         );
  82
  83         private $mQueryMetaModules = array (
  84                 'siteinfo' => 'ApiQuerySiteinfo',
  85                 'userinfo' => 'ApiQueryUserInfo',
  86                 'allmessages' => 'ApiQueryAllmessages',
  87         );
  88
  89         private $mSlaveDB = null;
  90         private $mNamedDB = array();
  91
  92         public function __construct($main, $action) {
  93                 parent :: __construct($main, $action);
  94
  95                 // Allow custom modules to be added in LocalSettings.php
  96                 global $wgApiPropModules, $wgApiListModules, $wgApiMetaModules;
  97                 self :: appendUserModules($this->mQueryPropModules, $wgApiPropModules);
  98                 self :: appendUserModules($this->mQueryListModules, $wgApiListModules);
  99                 self :: appendUserModules($this->mQueryMetaModules, $wgApiMetaModules);
 100
 101                 $this->mPropModuleNames = array_keys($this->mQueryPropModules);
 102                 $this->mListModuleNames = array_keys($this->mQueryListModules);
 103                 $this->mMetaModuleNames = array_keys($this->mQueryMetaModules);
 104
 105                 // Allow the entire list of modules at first,
 106                 // but during module instantiation check if it can be used as a generator.
 107                 $this->mAllowedGenerators = array_merge($this->mListModuleNames, $this->mPropModuleNames);
 108         }
 109
 110         /**
 111          * Helper function to append any add-in modules to the list
 112          */
 113         private static function appendUserModules(&$modules, $newModules) {
 114                 if (is_array( $newModules )) {
 115                         foreach ( $newModules as $moduleName => $moduleClass) {
 116                                 $modules[$moduleName] = $moduleClass;
 117                         }
 118                 }
 119         }
 120
 121         /**
 122          * Gets a default slave database connection object
 123          */
 124         public function getDB() {
 125                 if (!isset ($this->mSlaveDB)) {
 126                         $this->profileDBIn();
 127                         $this->mSlaveDB = wfGetDB(DB_SLAVE,'api');
 128                         $this->profileDBOut();
 129                 }
 130                 return $this->mSlaveDB;
 131         }
 132
 133         /**
 134          * Get the query database connection with the given name.
 135          * If no such connection has been requested before, it will be created.
 136          * Subsequent calls with the same $name will return the same connection
 137          * as the first, regardless of $db or $groups new values.
 138          */
 139         public function getNamedDB($name, $db, $groups) {
 140                 if (!array_key_exists($name, $this->mNamedDB)) {
 141                         $this->profileDBIn();
 142                         $this->mNamedDB[$name] = wfGetDB($db, $groups);
 143                         $this->profileDBOut();
 144                 }
 145                 return $this->mNamedDB[$name];
 146         }
 147
 148         /**
 149          * Gets the set of pages the user has requested (or generated)
 150          */
 151         public function getPageSet() {
 152                 return $this->mPageSet;
 153         }
 154
 155         /**
 156          * Get the array mapping module names to class names
 157          */
 158         function getModules() {
 159                 return array_merge($this->mQueryPropModules, $this->mQueryListModules, $this->mQueryMetaModules);
 160         }
 161
 162         /**
 163          * Query execution happens in the following steps:
 164          * #1 Create a PageSet object with any pages requested by the user
 165          * #2 If using generator, execute it to get a new PageSet object
 166          * #3 Instantiate all requested modules.
 167          *    This way the PageSet object will know what shared data is required,
 168          *    and minimize DB calls.
 169          * #4 Output all normalization and redirect resolution information
 170          * #5 Execute all requested modules
 171          */
 172         public function execute() {
 173
 174                 $this->params = $this->extractRequestParams();
 175                 $this->redirects = $this->params['redirects'];
 176
 177                 //
 178                 // Create PageSet
 179                 //
 180                 $this->mPageSet = new ApiPageSet($this, $this->redirects);
 181
 182                 //
 183                 // Instantiate requested modules
 184                 //
 185                 $modules = array ();
 186                 $this->InstantiateModules($modules, 'prop', $this->mQueryPropModules);
 187                 $this->InstantiateModules($modules, 'list', $this->mQueryListModules);
 188                 $this->InstantiateModules($modules, 'meta', $this->mQueryMetaModules);
 189
 190                 //
 191                 // If given, execute generator to substitute user supplied data with generated data.
 192                 //
 193                 if (isset ($this->params['generator'])) {
 194                         $this->executeGeneratorModule($this->params['generator'], $modules);
 195                 } else {
 196                         // Append custom fields and populate page/revision information
 197                         $this->addCustomFldsToPageSet($modules, $this->mPageSet);
 198                         $this->mPageSet->execute();
 199                 }
 200
 201                 //
 202                 // Record page information (title, namespace, if exists, etc)
 203                 //
 204                 $this->outputGeneralPageInfo();
 205
 206                 //
 207                 // Execute all requested modules.
 208                 //
 209                 foreach ($modules as $module) {
 210                         $module->profileIn();
 211                         $module->execute();
 212                         wfRunHooks('APIQueryAfterExecute', array(&$module));
 213                         $module->profileOut();
 214                 }
 215         }
 216
 217         /**
 218          * Query modules may optimize data requests through the $this->getPageSet() object
 219          * by adding extra fields from the page table.
 220          * This function will gather all the extra request fields from the modules.
 221          */
 222         private function addCustomFldsToPageSet($modules, $pageSet) {
 223                 // Query all requested modules.
 224                 foreach ($modules as $module) {
 225                         $module->requestExtraData($pageSet);
 226                 }
 227         }
 228
 229         /**
 230          * Create instances of all modules requested by the client
 231          */
 232         private function InstantiateModules(&$modules, $param, $moduleList) {
 233                 $list = @$this->params[$param];
 234                 if (!is_null ($list))
 235                         foreach ($list as $moduleName)
 236                                 $modules[] = new $moduleList[$moduleName] ($this, $moduleName);
 237         }
 238
 239         /**
 240          * Appends an element for each page in the current pageSet with the most general
 241          * information (id, title), plus any title normalizations and missing or invalid title/pageids/revids.
 242          */
 243         private function outputGeneralPageInfo() {
 244
 245                 $pageSet = $this->getPageSet();
 246                 $result = $this->getResult();
 247
 248                 // Title normalizations
 249                 $normValues = array ();
 250                 foreach ($pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr) {
 251                         $normValues[] = array (
 252                                 'from' => $rawTitleStr,
 253                                 'to' => $titleStr
 254                         );
 255                 }
 256
 257                 if (!empty ($normValues)) {
 258                         $result->setIndexedTagName($normValues, 'n');
 259                         $result->addValue('query', 'normalized', $normValues);
 260                 }
 261
 262                 // Interwiki titles
 263                 $intrwValues = array ();
 264                 foreach ($pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr) {
 265                         $intrwValues[] = array (
 266                                 'title' => $rawTitleStr,
 267                                 'iw' => $interwikiStr
 268                         );
 269                 }
 270
 271                 if (!empty ($intrwValues)) {
 272                         $result->setIndexedTagName($intrwValues, 'i');
 273                         $result->addValue('query', 'interwiki', $intrwValues);
 274                 }
 275
 276                 // Show redirect information
 277                 $redirValues = array ();
 278                 foreach ($pageSet->getRedirectTitles() as $titleStrFrom => $titleStrTo) {
 279                         $redirValues[] = array (
 280                                 'from' => strval($titleStrFrom),
 281                                 'to' => $titleStrTo
 282                         );
 283                 }
 284
 285                 if (!empty ($redirValues)) {
 286                         $result->setIndexedTagName($redirValues, 'r');
 287                         $result->addValue('query', 'redirects', $redirValues);
 288                 }
 289
 290                 //
 291                 // Missing revision elements
 292                 //
 293                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 294                 if (!empty ($missingRevIDs)) {
 295                         $revids = array ();
 296                         foreach ($missingRevIDs as $revid) {
 297                                 $revids[$revid] = array (
 298                                         'revid' => $revid
 299                                 );
 300                         }
 301                         $result->setIndexedTagName($revids, 'rev');
 302                         $result->addValue('query', 'badrevids', $revids);
 303                 }
 304
 305                 //
 306                 // Page elements
 307                 //
 308                 $pages = array ();
 309
 310                 // Report any missing titles
 311                 foreach ($pageSet->getMissingTitles() as $fakeId => $title) {
 312                         $vals = array();
 313                         ApiQueryBase :: addTitleInfo($vals, $title);
 314                         $vals['missing'] = '';
 315                         $pages[$fakeId] = $vals;
 316                 }
 317                 // Report any invalid titles
 318                 foreach ($pageSet->getInvalidTitles() as $fakeId => $title)
 319                         $pages[$fakeId] = array('title' => $title, 'invalid' => '');
 320                 // Report any missing page ids
 321                 foreach ($pageSet->getMissingPageIDs() as $pageid) {
 322                         $pages[$pageid] = array (
 323                                 'pageid' => $pageid,
 324                                 'missing' => ''
 325                         );
 326                 }
 327
 328                 // Output general page information for found titles
 329                 foreach ($pageSet->getGoodTitles() as $pageid => $title) {
 330                         $vals = array();
 331                         $vals['pageid'] = $pageid;
 332                         ApiQueryBase :: addTitleInfo($vals, $title);
 333                         $pages[$pageid] = $vals;
 334                 }
 335
 336                 if (!empty ($pages)) {
 337
 338                         if ($this->params['indexpageids']) {
 339                                 $pageIDs = array_keys($pages);
 340                                 // json treats all map keys as strings - converting to match
 341                                 $pageIDs = array_map('strval', $pageIDs);
 342                                 $result->setIndexedTagName($pageIDs, 'id');
 343                                 $result->addValue('query', 'pageids', $pageIDs);
 344                         }
 345
 346                         $result->setIndexedTagName($pages, 'page');
 347                         $result->addValue('query', 'pages', $pages);
 348                 }
 349         }
 350
 351         /**
 352          * For generator mode, execute generator, and use its output as new pageSet
 353          */
 354         protected function executeGeneratorModule($generatorName, $modules) {
 355
 356                 // Find class that implements requested generator
 357                 if (isset ($this->mQueryListModules[$generatorName])) {
 358                         $className = $this->mQueryListModules[$generatorName];
 359                 } elseif (isset ($this->mQueryPropModules[$generatorName])) {
 360                         $className = $this->mQueryPropModules[$generatorName];
 361                 } else {
 362                         ApiBase :: dieDebug(__METHOD__, "Unknown generator=$generatorName");
 363                 }
 364
 365                 // Generator results
 366                 $resultPageSet = new ApiPageSet($this, $this->redirects);
 367
 368                 // Create and execute the generator
 369                 $generator = new $className ($this, $generatorName);
 370                 if (!$generator instanceof ApiQueryGeneratorBase)
 371                         $this->dieUsage("Module $generatorName cannot be used as a generator", "badgenerator");
 372
 373                 $generator->setGeneratorMode();
 374
 375                 // Add any additional fields modules may need
 376                 $generator->requestExtraData($this->mPageSet);
 377                 $this->addCustomFldsToPageSet($modules, $resultPageSet);
 378
 379                 // Populate page information with the original user input
 380                 $this->mPageSet->execute();
 381
 382                 // populate resultPageSet with the generator output
 383                 $generator->profileIn();
 384                 $generator->executeGenerator($resultPageSet);
 385                 wfRunHooks('APIQueryGeneratorAfterExecute', array(&$generator, &$resultPageSet));
 386                 $resultPageSet->finishPageSetGeneration();
 387                 $generator->profileOut();
 388
 389                 // Swap the resulting pageset back in
 390                 $this->mPageSet = $resultPageSet;
 391         }
 392
 393         /**
 394          * Returns the list of allowed parameters for this module.
 395          * Qurey module also lists all ApiPageSet parameters as its own.
 396          */
 397         public function getAllowedParams() {
 398                 return array (
 399                         'prop' => array (
 400                                 ApiBase :: PARAM_ISMULTI => true,
 401                                 ApiBase :: PARAM_TYPE => $this->mPropModuleNames
 402                         ),
 403                         'list' => array (
 404                                 ApiBase :: PARAM_ISMULTI => true,
 405                                 ApiBase :: PARAM_TYPE => $this->mListModuleNames
 406                         ),
 407                         'meta' => array (
 408                                 ApiBase :: PARAM_ISMULTI => true,
 409                                 ApiBase :: PARAM_TYPE => $this->mMetaModuleNames
 410                         ),
 411                         'generator' => array (
 412                                 ApiBase :: PARAM_TYPE => $this->mAllowedGenerators
 413                         ),
 414                         'redirects' => false,
 415                         'indexpageids' => false,
 416                 );
 417         }
 418
 419         /**
 420          * Override the parent to generate help messages for all available query modules.
 421          */
 422         public function makeHelpMsg() {
 423
 424                 $msg = '';
 425
 426                 // Make sure the internal object is empty
 427                 // (just in case a sub-module decides to optimize during instantiation)
 428                 $this->mPageSet = null;
 429                 $this->mAllowedGenerators = array();    // Will be repopulated
 430
 431                 $astriks = str_repeat('--- ', 8);
 432                 $astriks2 = str_repeat('*** ', 10);
 433                 $msg .= "\n$astriks Query: Prop  $astriks\n\n";
 434                 $msg .= $this->makeHelpMsgHelper($this->mQueryPropModules, 'prop');
 435                 $msg .= "\n$astriks Query: List  $astriks\n\n";
 436                 $msg .= $this->makeHelpMsgHelper($this->mQueryListModules, 'list');
 437                 $msg .= "\n$astriks Query: Meta  $astriks\n\n";
 438                 $msg .= $this->makeHelpMsgHelper($this->mQueryMetaModules, 'meta');
 439                 $msg .= "\n\n$astriks2 Modules: continuation  $astriks2\n\n";
 440
 441                 // Perform the base call last because the $this->mAllowedGenerators
 442                 // will be updated inside makeHelpMsgHelper()
 443                 // Use parent to make default message for the query module
 444                 $msg = parent :: makeHelpMsg() . $msg;
 445
 446                 return $msg;
 447         }
 448
 449         /**
 450          * For all modules in $moduleList, generate help messages and join them together
 451          */
 452         private function makeHelpMsgHelper($moduleList, $paramName) {
 453
 454                 $moduleDscriptions = array ();
 455
 456                 foreach ($moduleList as $moduleName => $moduleClass) {
 457                         $module = new $moduleClass ($this, $moduleName, null);
 458
 459                         $msg = ApiMain::makeHelpMsgHeader($module, $paramName);
 460                         $msg2 = $module->makeHelpMsg();
 461                         if ($msg2 !== false)
 462                                 $msg .= $msg2;
 463                         if ($module instanceof ApiQueryGeneratorBase) {
 464                                 $this->mAllowedGenerators[] = $moduleName;
 465                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 466                         }
 467                         $moduleDscriptions[] = $msg;
 468                 }
 469
 470                 return implode("\n", $moduleDscriptions);
 471         }
 472
 473         /**
 474          * Override to add extra parameters from PageSet
 475          */
 476         public function makeHelpMsgParameters() {
 477                 $psModule = new ApiPageSet($this);
 478                 return $psModule->makeHelpMsgParameters() . parent :: makeHelpMsgParameters();
 479         }
 480
 481         // @todo should work correctly
 482         public function shouldCheckMaxlag() {
 483                 return true;
 484         }
 485
 486         public function getParamDescription() {
 487                 return array (
 488                         'prop' => 'Which properties to get for the titles/revisions/pageids',
 489                         'list' => 'Which lists to get',
 490                         'meta' => 'Which meta data to get about the site',
 491                         'generator' => 'Use the output of a list as the input for other prop/list/meta items',
 492                         'redirects' => 'Automatically resolve redirects',
 493                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs.'
 494                 );
 495         }
 496
 497         public function getDescription() {
 498                 return array (
 499                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 500                         'and is loosely based on the Query API interface currently available on all MediaWiki servers.',
 501                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites.'
 502                 );
 503         }
 504
 505         protected function getExamples() {
 506                 return array (
 507                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment'
 508                 );
 509         }
 510
 511         public function getVersion() {
 512                 $psModule = new ApiPageSet($this);
 513                 $vers = array ();
 514                 $vers[] = __CLASS__ . ': $Id$';
 515                 $vers[] = $psModule->getVersion();
 516                 return $vers;
 517         }
 518 }