includes/api/ApiQuery.php

   1 <?php
   2
   3 /*
   4  * Created on Sep 7, 2006
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  */
  25
  26 if (!defined('MEDIAWIKI')) {
  27         // Eclipse helper - will be ignored in production
  28         require_once ('ApiBase.php');
  29 }
  30
  31 /**
  32  * This is the main query class. It behaves similar to ApiMain: based on the parameters given,
  33  * it will create a list of titles to work on (an instance of the ApiPageSet object)
  34  * instantiate and execute various property/list/meta modules,
  35  * and assemble all resulting data into a single ApiResult object.
  36  *
  37  * In the generator mode, a generator will be first executed to populate a second ApiPageSet object,
  38  * and that object will be used for all subsequent modules.
  39  *
  40  * @addtogroup API
  41  */
  42 class ApiQuery extends ApiBase {
  43
  44         private $mPropModuleNames, $mListModuleNames, $mMetaModuleNames;
  45         private $mPageSet;
  46         private $params, $redirect;
  47
  48         private $mQueryPropModules = array (
  49                 'info' => 'ApiQueryInfo',
  50                 'revisions' => 'ApiQueryRevisions',
  51                 'links' => 'ApiQueryLinks',
  52                 'langlinks' => 'ApiQueryLangLinks',
  53                 'images' => 'ApiQueryImages',
  54                 'imageinfo' => 'ApiQueryImageInfo',
  55                 'templates' => 'ApiQueryLinks',
  56                 'categories' => 'ApiQueryCategories',
  57                 'extlinks' => 'ApiQueryExternalLinks',
  58         );
  59
  60         private $mQueryListModules = array (
  61                 'allpages' => 'ApiQueryAllpages',
  62                 'alllinks' => 'ApiQueryAllLinks',
  63                 'allcategories' => 'ApiQueryAllCategories',
  64                 'allusers' => 'ApiQueryAllUsers',
  65                 'backlinks' => 'ApiQueryBacklinks',
  66                 'blocks' => 'ApiQueryBlocks',
  67                 'categorymembers' => 'ApiQueryCategoryMembers',
  68                 'deletedrevs' => 'ApiQueryDeletedrevs',
  69                 'embeddedin' => 'ApiQueryBacklinks',
  70                 'imageusage' => 'ApiQueryBacklinks',
  71                 'logevents' => 'ApiQueryLogEvents',
  72                 'recentchanges' => 'ApiQueryRecentChanges',
  73                 'search' => 'ApiQuerySearch',
  74                 'usercontribs' => 'ApiQueryContributions',
  75                 'watchlist' => 'ApiQueryWatchlist',
  76                 'exturlusage' => 'ApiQueryExtLinksUsage',
  77         );
  78
  79         private $mQueryMetaModules = array (
  80                 'siteinfo' => 'ApiQuerySiteinfo',
  81                 'userinfo' => 'ApiQueryUserInfo',
  82                 'allmessages' => 'ApiQueryAllmessages',
  83         );
  84
  85         private $mSlaveDB = null;
  86         private $mNamedDB = array();
  87
  88         public function __construct($main, $action) {
  89                 parent :: __construct($main, $action);
  90
  91                 // Allow custom modules to be added in LocalSettings.php
  92                 global $wgApiQueryPropModules, $wgApiQueryListModules, $wgApiQueryMetaModules;
  93                 self :: appendUserModules($this->mQueryPropModules, $wgApiQueryPropModules);
  94                 self :: appendUserModules($this->mQueryListModules, $wgApiQueryListModules);
  95                 self :: appendUserModules($this->mQueryMetaModules, $wgApiQueryMetaModules);
  96
  97                 $this->mPropModuleNames = array_keys($this->mQueryPropModules);
  98                 $this->mListModuleNames = array_keys($this->mQueryListModules);
  99                 $this->mMetaModuleNames = array_keys($this->mQueryMetaModules);
 100
 101                 // Allow the entire list of modules at first,
 102                 // but during module instantiation check if it can be used as a generator.
 103                 $this->mAllowedGenerators = array_merge($this->mListModuleNames, $this->mPropModuleNames);
 104         }
 105
 106         /**
 107          * Helper function to append any add-in modules to the list
 108          */
 109         private static function appendUserModules(&$modules, $newModules) {
 110                 if (is_array( $newModules )) {
 111                         foreach ( $newModules as $moduleName => $moduleClass) {
 112                                 $modules[$moduleName] = $moduleClass;
 113                         }
 114                 }
 115         }
 116
 117         /**
 118          * Gets a default slave database connection object
 119          */
 120         public function getDB() {
 121                 if (!isset ($this->mSlaveDB)) {
 122                         $this->profileDBIn();
 123                         $this->mSlaveDB = wfGetDB(DB_SLAVE);
 124                         $this->profileDBOut();
 125                 }
 126                 return $this->mSlaveDB;
 127         }
 128
 129         /**
 130          * Get the query database connection with the given name.
 131          * If no such connection has been requested before, it will be created.
 132          * Subsequent calls with the same $name will return the same connection
 133          * as the first, regardless of $db or $groups new values.
 134          */
 135         public function getNamedDB($name, $db, $groups) {
 136                 if (!array_key_exists($name, $this->mNamedDB)) {
 137                         $this->profileDBIn();
 138                         $this->mNamedDB[$name] = wfGetDB($db, $groups);
 139                         $this->profileDBOut();
 140                 }
 141                 return $this->mNamedDB[$name];
 142         }
 143
 144         /**
 145          * Gets the set of pages the user has requested (or generated)
 146          */
 147         public function getPageSet() {
 148                 return $this->mPageSet;
 149         }
 150
 151         /**
 152          * Query execution happens in the following steps:
 153          * #1 Create a PageSet object with any pages requested by the user
 154          * #2 If using generator, execute it to get a new PageSet object
 155          * #3 Instantiate all requested modules.
 156          *    This way the PageSet object will know what shared data is required,
 157          *    and minimize DB calls.
 158          * #4 Output all normalization and redirect resolution information
 159          * #5 Execute all requested modules
 160          */
 161         public function execute() {
 162
 163                 $this->params = $this->extractRequestParams();
 164                 $this->redirects = $this->params['redirects'];
 165
 166                 //
 167                 // Create PageSet
 168                 //
 169                 $this->mPageSet = new ApiPageSet($this, $this->redirects);
 170
 171                 //
 172                 // Instantiate requested modules
 173                 //
 174                 $modules = array ();
 175                 $this->InstantiateModules($modules, 'prop', $this->mQueryPropModules);
 176                 $this->InstantiateModules($modules, 'list', $this->mQueryListModules);
 177                 $this->InstantiateModules($modules, 'meta', $this->mQueryMetaModules);
 178
 179                 //
 180                 // If given, execute generator to substitute user supplied data with generated data.
 181                 //
 182                 if (isset ($this->params['generator'])) {
 183                         $this->executeGeneratorModule($this->params['generator'], $modules);
 184                 } else {
 185                         // Append custom fields and populate page/revision information
 186                         $this->addCustomFldsToPageSet($modules, $this->mPageSet);
 187                         $this->mPageSet->execute();
 188                 }
 189
 190                 //
 191                 // Record page information (title, namespace, if exists, etc)
 192                 //
 193                 $this->outputGeneralPageInfo();
 194
 195                 //
 196                 // Execute all requested modules.
 197                 //
 198                 foreach ($modules as $module) {
 199                         $module->profileIn();
 200                         $module->execute();
 201                         $module->profileOut();
 202                 }
 203         }
 204
 205         /**
 206          * Query modules may optimize data requests through the $this->getPageSet() object
 207          * by adding extra fields from the page table.
 208          * This function will gather all the extra request fields from the modules.
 209          */
 210         private function addCustomFldsToPageSet($modules, $pageSet) {
 211                 // Query all requested modules.
 212                 foreach ($modules as $module) {
 213                         $module->requestExtraData($pageSet);
 214                 }
 215         }
 216
 217         /**
 218          * Create instances of all modules requested by the client
 219          */
 220         private function InstantiateModules(&$modules, $param, $moduleList) {
 221                 $list = $this->params[$param];
 222                 if (isset ($list))
 223                         foreach ($list as $moduleName)
 224                                 $modules[] = new $moduleList[$moduleName] ($this, $moduleName);
 225         }
 226
 227         /**
 228          * Appends an element for each page in the current pageSet with the most general
 229          * information (id, title), plus any title normalizations and missing title/pageids/revids.
 230          */
 231         private function outputGeneralPageInfo() {
 232
 233                 $pageSet = $this->getPageSet();
 234                 $result = $this->getResult();
 235
 236                 // Title normalizations
 237                 $normValues = array ();
 238                 foreach ($pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr) {
 239                         $normValues[] = array (
 240                                 'from' => $rawTitleStr,
 241                                 'to' => $titleStr
 242                         );
 243                 }
 244
 245                 if (!empty ($normValues)) {
 246                         $result->setIndexedTagName($normValues, 'n');
 247                         $result->addValue('query', 'normalized', $normValues);
 248                 }
 249
 250                 // Interwiki titles
 251                 $intrwValues = array ();
 252                 foreach ($pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr) {
 253                         $intrwValues[] = array (
 254                                 'title' => $rawTitleStr,
 255                                 'iw' => $interwikiStr
 256                         );
 257                 }
 258
 259                 if (!empty ($intrwValues)) {
 260                         $result->setIndexedTagName($intrwValues, 'i');
 261                         $result->addValue('query', 'interwiki', $intrwValues);
 262                 }
 263
 264                 // Show redirect information
 265                 $redirValues = array ();
 266                 foreach ($pageSet->getRedirectTitles() as $titleStrFrom => $titleStrTo) {
 267                         $redirValues[] = array (
 268                                 'from' => $titleStrFrom,
 269                                 'to' => $titleStrTo
 270                         );
 271                 }
 272
 273                 if (!empty ($redirValues)) {
 274                         $result->setIndexedTagName($redirValues, 'r');
 275                         $result->addValue('query', 'redirects', $redirValues);
 276                 }
 277
 278                 //
 279                 // Missing revision elements
 280                 //
 281                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 282                 if (!empty ($missingRevIDs)) {
 283                         $revids = array ();
 284                         foreach ($missingRevIDs as $revid) {
 285                                 $revids[$revid] = array (
 286                                         'revid' => $revid
 287                                 );
 288                         }
 289                         $result->setIndexedTagName($revids, 'rev');
 290                         $result->addValue('query', 'badrevids', $revids);
 291                 }
 292
 293                 //
 294                 // Page elements
 295                 //
 296                 $pages = array ();
 297
 298                 // Report any missing titles
 299                 foreach ($pageSet->getMissingTitles() as $fakeId => $title) {
 300                         $vals = array();
 301                         ApiQueryBase :: addTitleInfo($vals, $title);
 302                         $vals['missing'] = '';
 303                         $pages[$fakeId] = $vals;
 304                 }
 305
 306                 // Report any missing page ids
 307                 foreach ($pageSet->getMissingPageIDs() as $pageid) {
 308                         $pages[$pageid] = array (
 309                                 'pageid' => $pageid,
 310                                 'missing' => ''
 311                         );
 312                 }
 313
 314                 // Output general page information for found titles
 315                 foreach ($pageSet->getGoodTitles() as $pageid => $title) {
 316                         $vals = array();
 317                         $vals['pageid'] = $pageid;
 318                         ApiQueryBase :: addTitleInfo($vals, $title);
 319                         $pages[$pageid] = $vals;
 320                 }
 321
 322                 if (!empty ($pages)) {
 323
 324                         if ($this->params['indexpageids']) {
 325                                 $pageIDs = array_keys($pages);
 326                                 // json treats all map keys as strings - converting to match
 327                                 $pageIDs = array_map('strval', $pageIDs);
 328                                 $result->setIndexedTagName($pageIDs, 'id');
 329                                 $result->addValue('query', 'pageids', $pageIDs);
 330                         }
 331
 332                         $result->setIndexedTagName($pages, 'page');
 333                         $result->addValue('query', 'pages', $pages);
 334                 }
 335         }
 336
 337         /**
 338          * For generator mode, execute generator, and use its output as new pageSet
 339          */
 340         protected function executeGeneratorModule($generatorName, $modules) {
 341
 342                 // Find class that implements requested generator
 343                 if (isset ($this->mQueryListModules[$generatorName])) {
 344                         $className = $this->mQueryListModules[$generatorName];
 345                 } elseif (isset ($this->mQueryPropModules[$generatorName])) {
 346                         $className = $this->mQueryPropModules[$generatorName];
 347                 } else {
 348                         ApiBase :: dieDebug(__METHOD__, "Unknown generator=$generatorName");
 349                 }
 350
 351                 // Generator results
 352                 $resultPageSet = new ApiPageSet($this, $this->redirects);
 353
 354                 // Create and execute the generator
 355                 $generator = new $className ($this, $generatorName);
 356                 if (!$generator instanceof ApiQueryGeneratorBase)
 357                         $this->dieUsage("Module $generatorName cannot be used as a generator", "badgenerator");
 358
 359                 $generator->setGeneratorMode();
 360
 361                 // Add any additional fields modules may need
 362                 $generator->requestExtraData($this->mPageSet);
 363                 $this->addCustomFldsToPageSet($modules, $resultPageSet);
 364
 365                 // Populate page information with the original user input
 366                 $this->mPageSet->execute();
 367
 368                 // populate resultPageSet with the generator output
 369                 $generator->profileIn();
 370                 $generator->executeGenerator($resultPageSet);
 371                 $resultPageSet->finishPageSetGeneration();
 372                 $generator->profileOut();
 373
 374                 // Swap the resulting pageset back in
 375                 $this->mPageSet = $resultPageSet;
 376         }
 377
 378         /**
 379          * Returns the list of allowed parameters for this module.
 380          * Qurey module also lists all ApiPageSet parameters as its own.
 381          */
 382         protected function getAllowedParams() {
 383                 return array (
 384                         'prop' => array (
 385                                 ApiBase :: PARAM_ISMULTI => true,
 386                                 ApiBase :: PARAM_TYPE => $this->mPropModuleNames
 387                         ),
 388                         'list' => array (
 389                                 ApiBase :: PARAM_ISMULTI => true,
 390                                 ApiBase :: PARAM_TYPE => $this->mListModuleNames
 391                         ),
 392                         'meta' => array (
 393                                 ApiBase :: PARAM_ISMULTI => true,
 394                                 ApiBase :: PARAM_TYPE => $this->mMetaModuleNames
 395                         ),
 396                         'generator' => array (
 397                                 ApiBase :: PARAM_TYPE => $this->mAllowedGenerators
 398                         ),
 399                         'redirects' => false,
 400                         'indexpageids' => false,
 401                 );
 402         }
 403
 404         /**
 405          * Override the parent to generate help messages for all available query modules.
 406          */
 407         public function makeHelpMsg() {
 408
 409                 $msg = '';
 410
 411                 // Make sure the internal object is empty
 412                 // (just in case a sub-module decides to optimize during instantiation)
 413                 $this->mPageSet = null;
 414                 $this->mAllowedGenerators = array();    // Will be repopulated
 415
 416                 $astriks = str_repeat('--- ', 8);
 417                 $msg .= "\n$astriks Query: Prop  $astriks\n\n";
 418                 $msg .= $this->makeHelpMsgHelper($this->mQueryPropModules, 'prop');
 419                 $msg .= "\n$astriks Query: List  $astriks\n\n";
 420                 $msg .= $this->makeHelpMsgHelper($this->mQueryListModules, 'list');
 421                 $msg .= "\n$astriks Query: Meta  $astriks\n\n";
 422                 $msg .= $this->makeHelpMsgHelper($this->mQueryMetaModules, 'meta');
 423
 424                 // Perform the base call last because the $this->mAllowedGenerators
 425                 // will be updated inside makeHelpMsgHelper()
 426                 // Use parent to make default message for the query module
 427                 $msg = parent :: makeHelpMsg() . $msg;
 428
 429                 return $msg;
 430         }
 431
 432         /**
 433          * For all modules in $moduleList, generate help messages and join them together
 434          */
 435         private function makeHelpMsgHelper($moduleList, $paramName) {
 436
 437                 $moduleDscriptions = array ();
 438
 439                 foreach ($moduleList as $moduleName => $moduleClass) {
 440                         $module = new $moduleClass ($this, $moduleName, null);
 441
 442                         $msg = ApiMain::makeHelpMsgHeader($module, $paramName);
 443                         $msg2 = $module->makeHelpMsg();
 444                         if ($msg2 !== false)
 445                                 $msg .= $msg2;
 446                         if ($module instanceof ApiQueryGeneratorBase) {
 447                                 $this->mAllowedGenerators[] = $moduleName;
 448                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 449                         }
 450                         $moduleDscriptions[] = $msg;
 451                 }
 452
 453                 return implode("\n", $moduleDscriptions);
 454         }
 455
 456         /**
 457          * Override to add extra parameters from PageSet
 458          */
 459         public function makeHelpMsgParameters() {
 460                 $psModule = new ApiPageSet($this);
 461                 return $psModule->makeHelpMsgParameters() . parent :: makeHelpMsgParameters();
 462         }
 463
 464         // @todo should work correctly
 465         public function shouldCheckMaxlag() {
 466                 return true;
 467         }
 468
 469         protected function getParamDescription() {
 470                 return array (
 471                         'prop' => 'Which properties to get for the titles/revisions/pageids',
 472                         'list' => 'Which lists to get',
 473                         'meta' => 'Which meta data to get about the site',
 474                         'generator' => 'Use the output of a list as the input for other prop/list/meta items',
 475                         'redirects' => 'Automatically resolve redirects',
 476                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs.'
 477                 );
 478         }
 479
 480         protected function getDescription() {
 481                 return array (
 482                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 483                         'and is loosely based on the Query API interface currently available on all MediaWiki servers.',
 484                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites.'
 485                 );
 486         }
 487
 488         protected function getExamples() {
 489                 return array (
 490                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment'
 491                 );
 492         }
 493
 494         public function getVersion() {
 495                 $psModule = new ApiPageSet($this);
 496                 $vers = array ();
 497                 $vers[] = __CLASS__ . ': $Id$';
 498                 $vers[] = $psModule->getVersion();
 499                 return $vers;
 500         }
 501 }
 502