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