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