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