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                 'templates' => 'ApiQueryLinks',
  55                 'categories' => 'ApiQueryCategories',
  56                 'extlinks' => 'ApiQueryExternalLinks',
  57         );
  58         //      'categories' => 'ApiQueryCategories',
  59         //      'imageinfo' => 'ApiQueryImageinfo',
  60         //      'templates' => 'ApiQueryTemplates',
  61
  62         private $mQueryListModules = array (
  63                 'allpages' => 'ApiQueryAllpages',
  64                 'logevents' => 'ApiQueryLogEvents',
  65                 'watchlist' => 'ApiQueryWatchlist',
  66                 'recentchanges' => 'ApiQueryRecentChanges',
  67                 'backlinks' => 'ApiQueryBacklinks',
  68                 'embeddedin' => 'ApiQueryBacklinks',
  69                 'imageusage' => 'ApiQueryBacklinks',
  70                 'usercontribs' => 'ApiQueryContributions'
  71         );
  72         //      'categorymembers' => 'ApiQueryCategorymembers',
  73         //      'recentchanges' => 'ApiQueryRecentchanges',
  74         //      'users' => 'ApiQueryUsers',
  75         //      'watchlist' => 'ApiQueryWatchlist',
  76
  77         private $mQueryMetaModules = array (
  78                 'siteinfo' => 'ApiQuerySiteinfo'
  79         );
  80         //      'userinfo' => 'ApiQueryUserinfo',
  81
  82         private $mSlaveDB = null;
  83         private $mNamedDB = array();
  84
  85         public function __construct($main, $action) {
  86                 parent :: __construct($main, $action);
  87
  88                 // Allow custom modules to be added in LocalSettings.php
  89                 global $wgApiQueryPropModules, $wgApiQueryListModules, $wgApiQueryMetaModules;
  90                 self :: appendUserModules($this->mQueryPropModules, $wgApiQueryPropModules);
  91                 self :: appendUserModules($this->mQueryListModules, $wgApiQueryListModules);
  92                 self :: appendUserModules($this->mQueryMetaModules, $wgApiQueryMetaModules);
  93
  94                 $this->mPropModuleNames = array_keys($this->mQueryPropModules);
  95                 $this->mListModuleNames = array_keys($this->mQueryListModules);
  96                 $this->mMetaModuleNames = array_keys($this->mQueryMetaModules);
  97
  98                 // Allow the entire list of modules at first,
  99                 // but during module instantiation check if it can be used as a generator.
 100                 $this->mAllowedGenerators = array_merge($this->mListModuleNames, $this->mPropModuleNames);
 101         }
 102
 103         private static function appendUserModules(&$modules, $newModules) {
 104                 if (is_array( $newModules )) {
 105                         foreach ( $newModules as $moduleName => $moduleClass) {
 106                                 $modules[$moduleName] = $moduleClass;
 107                         }
 108                 }
 109         }
 110
 111         public function getDB() {
 112                 if (!isset ($this->mSlaveDB)) {
 113                         $this->profileDBIn();
 114                         $this->mSlaveDB = wfGetDB(DB_SLAVE);
 115                         $this->profileDBOut();
 116                 }
 117                 return $this->mSlaveDB;
 118         }
 119
 120         /**
 121          * Get the query database connection with the given name.
 122          * If no such connection has been requested before, it will be created.
 123          * Subsequent calls with the same $name will return the same connection
 124          * as the first, regardless of $db or $groups new values.
 125          */
 126         public function getNamedDB($name, $db, $groups) {
 127                 if (!array_key_exists($name, $this->mNamedDB)) {
 128                         $this->profileDBIn();
 129                         $this->mNamedDB[$name] = wfGetDB($db, $groups);
 130                         $this->profileDBOut();
 131                 }
 132                 return $this->mNamedDB[$name];
 133         }
 134
 135         public function getPageSet() {
 136                 return $this->mPageSet;
 137         }
 138
 139         /**
 140          * Query execution happens in the following steps:
 141          * #1 Create a PageSet object with any pages requested by the user
 142          * #2 If using generator, execute it to get a new PageSet object
 143          * #3 Instantiate all requested modules.
 144          *    This way the PageSet object will know what shared data is required,
 145          *    and minimize DB calls.
 146          * #4 Output all normalization and redirect resolution information
 147          * #5 Execute all requested modules
 148          */
 149         public function execute() {
 150
 151                 $this->params = $this->extractRequestParams();
 152                 $this->redirects = $this->params['redirects'];
 153
 154                 //
 155                 // Create PageSet
 156                 //
 157                 $this->mPageSet = new ApiPageSet($this, $this->redirects);
 158
 159                 //
 160                 // Instantiate requested modules
 161                 //
 162                 $modules = array ();
 163                 $this->InstantiateModules($modules, 'prop', $this->mQueryPropModules);
 164                 $this->InstantiateModules($modules, 'list', $this->mQueryListModules);
 165                 $this->InstantiateModules($modules, 'meta', $this->mQueryMetaModules);
 166
 167                 //
 168                 // If given, execute generator to substitute user supplied data with generated data.
 169                 //
 170                 if (isset ($this->params['generator'])) {
 171                         $this->executeGeneratorModule($this->params['generator'], $modules);
 172                 } else {
 173                         // Append custom fields and populate page/revision information
 174                         $this->addCustomFldsToPageSet($modules, $this->mPageSet);
 175                         $this->mPageSet->execute();
 176                 }
 177
 178                 //
 179                 // Record page information (title, namespace, if exists, etc)
 180                 //
 181                 $this->outputGeneralPageInfo();
 182
 183                 //
 184                 // Execute all requested modules.
 185                 //
 186                 foreach ($modules as $module) {
 187                         $module->profileIn();
 188                         $module->execute();
 189                         $module->profileOut();
 190                 }
 191         }
 192
 193         /**
 194          * Query modules may optimize data requests through the $this->getPageSet() object
 195          * by adding extra fields from the page table.
 196          * This function will gather all the extra request fields from the modules.
 197          */
 198         private function addCustomFldsToPageSet($modules, $pageSet) {
 199                 // Query all requested modules.
 200                 foreach ($modules as $module) {
 201                         $module->requestExtraData($pageSet);
 202                 }
 203         }
 204
 205         /**
 206          * Create instances of all modules requested by the client
 207          */
 208         private function InstantiateModules(&$modules, $param, $moduleList) {
 209                 $list = $this->params[$param];
 210                 if (isset ($list))
 211                         foreach ($list as $moduleName)
 212                                 $modules[] = new $moduleList[$moduleName] ($this, $moduleName);
 213         }
 214
 215         /**
 216          * Appends an element for each page in the current pageSet with the most general
 217          * information (id, title), plus any title normalizations and missing title/pageids/revids.
 218          */
 219         private function outputGeneralPageInfo() {
 220
 221                 $pageSet = $this->getPageSet();
 222                 $result = $this->getResult();
 223
 224                 // Title normalizations
 225                 $normValues = array ();
 226                 foreach ($pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr) {
 227                         $normValues[] = array (
 228                                 'from' => $rawTitleStr,
 229                                 'to' => $titleStr
 230                         );
 231                 }
 232
 233                 if (!empty ($normValues)) {
 234                         $result->setIndexedTagName($normValues, 'n');
 235                         $result->addValue('query', 'normalized', $normValues);
 236                 }
 237
 238                 // Show redirect information
 239                 $redirValues = array ();
 240                 foreach ($pageSet->getRedirectTitles() as $titleStrFrom => $titleStrTo) {
 241                         $redirValues[] = array (
 242                                 'from' => $titleStrFrom,
 243                                 'to' => $titleStrTo
 244                         );
 245                 }
 246
 247                 if (!empty ($redirValues)) {
 248                         $result->setIndexedTagName($redirValues, 'r');
 249                         $result->addValue('query', 'redirects', $redirValues);
 250                 }
 251
 252                 //
 253                 // Missing revision elements
 254                 //
 255                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 256                 if (!empty ($missingRevIDs)) {
 257                         $revids = array ();
 258                         foreach ($missingRevIDs as $revid) {
 259                                 $revids[$revid] = array (
 260                                         'revid' => $revid
 261                                 );
 262                         }
 263                         $result->setIndexedTagName($revids, 'rev');
 264                         $result->addValue('query', 'badrevids', $revids);
 265                 }
 266
 267                 //
 268                 // Page elements
 269                 //
 270                 $pages = array ();
 271
 272                 // Report any missing titles
 273                 $fakepageid = -1;
 274                 foreach ($pageSet->getMissingTitles() as $title) {
 275                         $vals = array();
 276                         ApiQueryBase :: addTitleInfo($vals, $title, true);
 277                         $vals['missing'] = '';
 278                         $pages[$fakepageid--] = $vals;
 279                 }
 280
 281                 // Report any missing page ids
 282                 foreach ($pageSet->getMissingPageIDs() as $pageid) {
 283                         $pages[$pageid] = array (
 284                                 'pageid' => $pageid,
 285                                 'missing' => ''
 286                         );
 287                 }
 288
 289                 // Output general page information for found titles
 290                 foreach ($pageSet->getGoodTitles() as $pageid => $title) {
 291                         $vals = array();
 292                         $vals['pageid'] = $pageid;
 293                         ApiQueryBase :: addTitleInfo($vals, $title, true);
 294                         $pages[$pageid] = $vals;
 295                 }
 296
 297                 if (!empty ($pages)) {
 298
 299                         if ($this->params['indexpageids']) {
 300                                 $pageIDs = array_keys($pages);
 301                                 // json treats all map keys as strings - converting to match
 302                                 $pageIDs = array_map('strval', $pageIDs);
 303                                 $result->setIndexedTagName($pageIDs, 'id');
 304                                 $result->addValue('query', 'pageids', $pageIDs);
 305                         }
 306
 307                         $result->setIndexedTagName($pages, 'page');
 308                         $result->addValue('query', 'pages', $pages);
 309                 }
 310         }
 311
 312         /**
 313          * For generator mode, execute generator, and use its output as new pageSet
 314          */
 315         protected function executeGeneratorModule($generatorName, $modules) {
 316
 317                 // Find class that implements requested generator
 318                 if (isset ($this->mQueryListModules[$generatorName])) {
 319                         $className = $this->mQueryListModules[$generatorName];
 320                 } elseif (isset ($this->mQueryPropModules[$generatorName])) {
 321                         $className = $this->mQueryPropModules[$generatorName];
 322                 } else {
 323                         ApiBase :: dieDebug(__METHOD__, "Unknown generator=$generatorName");
 324                 }
 325
 326                 // Generator results
 327                 $resultPageSet = new ApiPageSet($this, $this->redirects);
 328
 329                 // Create and execute the generator
 330                 $generator = new $className ($this, $generatorName);
 331                 if (!$generator instanceof ApiQueryGeneratorBase)
 332                         $this->dieUsage("Module $generatorName cannot be used as a generator", "badgenerator");
 333
 334                 $generator->setGeneratorMode();
 335
 336                 // Add any additional fields modules may need
 337                 $generator->requestExtraData($this->mPageSet);
 338                 $this->addCustomFldsToPageSet($modules, $resultPageSet);
 339
 340                 // Populate page information with the original user input
 341                 $this->mPageSet->execute();
 342
 343                 // populate resultPageSet with the generator output
 344                 $generator->profileIn();
 345                 $generator->executeGenerator($resultPageSet);
 346                 $resultPageSet->finishPageSetGeneration();
 347                 $generator->profileOut();
 348
 349                 // Swap the resulting pageset back in
 350                 $this->mPageSet = $resultPageSet;
 351         }
 352
 353         /**
 354          * Returns the list of allowed parameters for this module.
 355          * Qurey module also lists all ApiPageSet parameters as its own.
 356          */
 357         protected function getAllowedParams() {
 358                 return array (
 359                         'prop' => array (
 360                                 ApiBase :: PARAM_ISMULTI => true,
 361                                 ApiBase :: PARAM_TYPE => $this->mPropModuleNames
 362                         ),
 363                         'list' => array (
 364                                 ApiBase :: PARAM_ISMULTI => true,
 365                                 ApiBase :: PARAM_TYPE => $this->mListModuleNames
 366                         ),
 367                         'meta' => array (
 368                                 ApiBase :: PARAM_ISMULTI => true,
 369                                 ApiBase :: PARAM_TYPE => $this->mMetaModuleNames
 370                         ),
 371                         'generator' => array (
 372                                 ApiBase :: PARAM_TYPE => $this->mAllowedGenerators
 373                         ),
 374                         'redirects' => false,
 375                         'indexpageids' => false,
 376                 );
 377         }
 378
 379         /**
 380          * Override the parent to generate help messages for all available query modules.
 381          */
 382         public function makeHelpMsg() {
 383
 384                 // Use parent to make default message for the query module
 385                 $msg = parent :: makeHelpMsg();
 386
 387                 // Make sure the internal object is empty
 388                 // (just in case a sub-module decides to optimize during instantiation)
 389                 $this->mPageSet = null;
 390
 391                 $astriks = str_repeat('--- ', 8);
 392                 $msg .= "\n$astriks Query: Prop  $astriks\n\n";
 393                 $msg .= $this->makeHelpMsgHelper($this->mQueryPropModules, 'prop');
 394                 $msg .= "\n$astriks Query: List  $astriks\n\n";
 395                 $msg .= $this->makeHelpMsgHelper($this->mQueryListModules, 'list');
 396                 $msg .= "\n$astriks Query: Meta  $astriks\n\n";
 397                 $msg .= $this->makeHelpMsgHelper($this->mQueryMetaModules, 'meta');
 398
 399                 return $msg;
 400         }
 401
 402         /**
 403          * For all modules in $moduleList, generate help messages and join them together
 404          */
 405         private function makeHelpMsgHelper($moduleList, $paramName) {
 406
 407                 $moduleDscriptions = array ();
 408
 409                 foreach ($moduleList as $moduleName => $moduleClass) {
 410                         $module = new $moduleClass ($this, $moduleName, null);
 411
 412                         $msg = ApiMain::makeHelpMsgHeader($module, $paramName);
 413                         $msg2 = $module->makeHelpMsg();
 414                         if ($msg2 !== false)
 415                                 $msg .= $msg2;
 416                         if ($module instanceof ApiQueryGeneratorBase)
 417                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 418                         $moduleDscriptions[] = $msg;
 419                 }
 420
 421                 return implode("\n", $moduleDscriptions);
 422         }
 423
 424         /**
 425          * Override to add extra parameters from PageSet
 426          */
 427         public function makeHelpMsgParameters() {
 428                 $psModule = new ApiPageSet($this);
 429                 return $psModule->makeHelpMsgParameters() . parent :: makeHelpMsgParameters();
 430         }
 431
 432         protected function getParamDescription() {
 433                 return array (
 434                         'prop' => 'Which properties to get for the titles/revisions/pageids',
 435                         'list' => 'Which lists to get',
 436                         'meta' => 'Which meta data to get about the site',
 437                         'generator' => 'Use the output of a list as the input for other prop/list/meta items',
 438                         'redirects' => 'Automatically resolve redirects',
 439                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs.'
 440                 );
 441         }
 442
 443         protected function getDescription() {
 444                 return array (
 445                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 446                         'and is loosely based on the Query API interface currently available on all MediaWiki servers.',
 447                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites.'
 448                 );
 449         }
 450
 451         protected function getExamples() {
 452                 return array (
 453                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment'
 454                 );
 455         }
 456
 457         public function getVersion() {
 458                 $psModule = new ApiPageSet($this);
 459                 $vers = array ();
 460                 $vers[] = __CLASS__ . ': $Id$';
 461                 $vers[] = $psModule->getVersion();
 462                 return $vers;
 463         }
 464 }
 465 ?>