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