includes/api/ApiPageSet.php

   1 <?php
   2 /**
   3  * Copyright © 2006, 2013 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22 use MediaWiki\MediaWikiServices;
  23 use Wikimedia\Rdbms\IResultWrapper;
  24 use Wikimedia\Rdbms\IDatabase;
  25
  26 /**
  27  * This class contains a list of pages that the client has requested.
  28  * Initially, when the client passes in titles=, pageids=, or revisions=
  29  * parameter, an instance of the ApiPageSet class will normalize titles,
  30  * determine if the pages/revisions exist, and prefetch any additional page
  31  * data requested.
  32  *
  33  * When a generator is used, the result of the generator will become the input
  34  * for the second instance of this class, and all subsequent actions will use
  35  * the second instance for all their work.
  36  *
  37  * @ingroup API
  38  * @since 1.21 derives from ApiBase instead of ApiQueryBase
  39  */
  40 class ApiPageSet extends ApiBase {
  41         /**
  42          * Constructor flag: The new instance of ApiPageSet will ignore the 'generator=' parameter
  43          * @since 1.21
  44          */
  45         const DISABLE_GENERATORS = 1;
  46
  47         private $mDbSource;
  48         private $mParams;
  49         private $mResolveRedirects;
  50         private $mConvertTitles;
  51         private $mAllowGenerator;
  52
  53         private $mAllPages = []; // [ns][dbkey] => page_id or negative when missing
  54         private $mTitles = [];
  55         private $mGoodAndMissingPages = []; // [ns][dbkey] => page_id or negative when missing
  56         private $mGoodPages = []; // [ns][dbkey] => page_id
  57         private $mGoodTitles = [];
  58         private $mMissingPages = []; // [ns][dbkey] => fake page_id
  59         private $mMissingTitles = [];
  60         /** @var array [fake_page_id] => [ 'title' => $title, 'invalidreason' => $reason ] */
  61         private $mInvalidTitles = [];
  62         private $mMissingPageIDs = [];
  63         private $mRedirectTitles = [];
  64         private $mSpecialTitles = [];
  65         private $mAllSpecials = []; // separate from mAllPages to avoid breaking getAllTitlesByNamespace()
  66         private $mNormalizedTitles = [];
  67         private $mInterwikiTitles = [];
  68         /** @var Title[] */
  69         private $mPendingRedirectIDs = [];
  70         private $mPendingRedirectSpecialPages = []; // [dbkey] => [ Title $from, Title $to ]
  71         private $mResolvedRedirectTitles = [];
  72         private $mConvertedTitles = [];
  73         private $mGoodRevIDs = [];
  74         private $mLiveRevIDs = [];
  75         private $mDeletedRevIDs = [];
  76         private $mMissingRevIDs = [];
  77         private $mGeneratorData = []; // [ns][dbkey] => data array
  78         private $mFakePageId = -1;
  79         private $mCacheMode = 'public';
  80         /** @var array */
  81         private $mRequestedPageFields = [];
  82         /** @var int */
  83         private $mDefaultNamespace = NS_MAIN;
  84         /** @var callable|null */
  85         private $mRedirectMergePolicy;
  86
  87         /**
  88          * Add all items from $values into the result
  89          * @param array $result Output
  90          * @param array $values Values to add
  91          * @param string[] $flags The names of boolean flags to mark this element
  92          * @param string $name If given, name of the value
  93          */
  94         private static function addValues( array &$result, $values, $flags = [], $name = null ) {
  95                 foreach ( $values as $val ) {
  96                         if ( $val instanceof Title ) {
  97                                 $v = [];
  98                                 ApiQueryBase::addTitleInfo( $v, $val );
  99                         } elseif ( $name !== null ) {
 100                                 $v = [ $name => $val ];
 101                         } else {
 102                                 $v = $val;
 103                         }
 104                         foreach ( $flags as $flag ) {
 105                                 $v[$flag] = true;
 106                         }
 107                         $result[] = $v;
 108                 }
 109         }
 110
 111         /**
 112          * @param ApiBase $dbSource Module implementing getDB().
 113          *        Allows PageSet to reuse existing db connection from the shared state like ApiQuery.
 114          * @param int $flags Zero or more flags like DISABLE_GENERATORS
 115          * @param int $defaultNamespace The namespace to use if none is specified by a prefix.
 116          * @since 1.21 accepts $flags instead of two boolean values
 117          */
 118         public function __construct( ApiBase $dbSource, $flags = 0, $defaultNamespace = NS_MAIN ) {
 119                 parent::__construct( $dbSource->getMain(), $dbSource->getModuleName() );
 120                 $this->mDbSource = $dbSource;
 121                 $this->mAllowGenerator = ( $flags & self::DISABLE_GENERATORS ) == 0;
 122                 $this->mDefaultNamespace = $defaultNamespace;
 123
 124                 $this->mParams = $this->extractRequestParams();
 125                 $this->mResolveRedirects = $this->mParams['redirects'];
 126                 $this->mConvertTitles = $this->mParams['converttitles'];
 127         }
 128
 129         /**
 130          * In case execute() is not called, call this method to mark all relevant parameters as used
 131          * This prevents unused parameters from being reported as warnings
 132          */
 133         public function executeDryRun() {
 134                 $this->executeInternal( true );
 135         }
 136
 137         /**
 138          * Populate the PageSet from the request parameters.
 139          */
 140         public function execute() {
 141                 $this->executeInternal( false );
 142         }
 143
 144         /**
 145          * Populate the PageSet from the request parameters.
 146          * @param bool $isDryRun If true, instantiates generator, but only to mark
 147          *    relevant parameters as used
 148          */
 149         private function executeInternal( $isDryRun ) {
 150                 $generatorName = $this->mAllowGenerator ? $this->mParams['generator'] : null;
 151                 if ( isset( $generatorName ) ) {
 152                         $dbSource = $this->mDbSource;
 153                         if ( !$dbSource instanceof ApiQuery ) {
 154                                 // If the parent container of this pageset is not ApiQuery, we must create it to run generator
 155                                 $dbSource = $this->getMain()->getModuleManager()->getModule( 'query' );
 156                         }
 157                         $generator = $dbSource->getModuleManager()->getModule( $generatorName, null, true );
 158                         if ( $generator === null ) {
 159                                 $this->dieWithError( [ 'apierror-badgenerator-unknown', $generatorName ], 'badgenerator' );
 160                         }
 161                         if ( !$generator instanceof ApiQueryGeneratorBase ) {
 162                                 $this->dieWithError( [ 'apierror-badgenerator-notgenerator', $generatorName ], 'badgenerator' );
 163                         }
 164                         // Create a temporary pageset to store generator's output,
 165                         // add any additional fields generator may need, and execute pageset to populate titles/pageids
 166                         $tmpPageSet = new ApiPageSet( $dbSource, self::DISABLE_GENERATORS );
 167                         $generator->setGeneratorMode( $tmpPageSet );
 168                         $this->mCacheMode = $generator->getCacheMode( $generator->extractRequestParams() );
 169
 170                         if ( !$isDryRun ) {
 171                                 $generator->requestExtraData( $tmpPageSet );
 172                         }
 173                         $tmpPageSet->executeInternal( $isDryRun );
 174
 175                         // populate this pageset with the generator output
 176                         if ( !$isDryRun ) {
 177                                 $generator->executeGenerator( $this );
 178
 179                                 // Avoid PHP 7.1 warning of passing $this by reference
 180                                 $apiModule = $this;
 181                                 Hooks::run( 'APIQueryGeneratorAfterExecute', [ &$generator, &$apiModule ] );
 182                         } else {
 183                                 // Prevent warnings from being reported on these parameters
 184                                 $main = $this->getMain();
 185                                 foreach ( $generator->extractRequestParams() as $paramName => $param ) {
 186                                         $main->markParamsUsed( $generator->encodeParamName( $paramName ) );
 187                                 }
 188                         }
 189
 190                         if ( !$isDryRun ) {
 191                                 $this->resolvePendingRedirects();
 192                         }
 193                 } else {
 194                         // Only one of the titles/pageids/revids is allowed at the same time
 195                         $dataSource = null;
 196                         if ( isset( $this->mParams['titles'] ) ) {
 197                                 $dataSource = 'titles';
 198                         }
 199                         if ( isset( $this->mParams['pageids'] ) ) {
 200                                 if ( isset( $dataSource ) ) {
 201                                         $this->dieWithError(
 202                                                 [
 203                                                         'apierror-invalidparammix-cannotusewith',
 204                                                         $this->encodeParamName( 'pageids' ),
 205                                                         $this->encodeParamName( $dataSource )
 206                                                 ],
 207                                                 'multisource'
 208                                         );
 209                                 }
 210                                 $dataSource = 'pageids';
 211                         }
 212                         if ( isset( $this->mParams['revids'] ) ) {
 213                                 if ( isset( $dataSource ) ) {
 214                                         $this->dieWithError(
 215                                                 [
 216                                                         'apierror-invalidparammix-cannotusewith',
 217                                                         $this->encodeParamName( 'revids' ),
 218                                                         $this->encodeParamName( $dataSource )
 219                                                 ],
 220                                                 'multisource'
 221                                         );
 222                                 }
 223                                 $dataSource = 'revids';
 224                         }
 225
 226                         if ( !$isDryRun ) {
 227                                 // Populate page information with the original user input
 228                                 switch ( $dataSource ) {
 229                                         case 'titles':
 230                                                 $this->initFromTitles( $this->mParams['titles'] );
 231                                                 break;
 232                                         case 'pageids':
 233                                                 $this->initFromPageIds( $this->mParams['pageids'] );
 234                                                 break;
 235                                         case 'revids':
 236                                                 if ( $this->mResolveRedirects ) {
 237                                                         $this->addWarning( 'apiwarn-redirectsandrevids' );
 238                                                 }
 239                                                 $this->mResolveRedirects = false;
 240                                                 $this->initFromRevIDs( $this->mParams['revids'] );
 241                                                 break;
 242                                         default:
 243                                                 // Do nothing - some queries do not need any of the data sources.
 244                                                 break;
 245                                 }
 246                         }
 247                 }
 248         }
 249
 250         /**
 251          * Check whether this PageSet is resolving redirects
 252          * @return bool
 253          */
 254         public function isResolvingRedirects() {
 255                 return $this->mResolveRedirects;
 256         }
 257
 258         /**
 259          * Return the parameter name that is the source of data for this PageSet
 260          *
 261          * If multiple source parameters are specified (e.g. titles and pageids),
 262          * one will be named arbitrarily.
 263          *
 264          * @return string|null
 265          */
 266         public function getDataSource() {
 267                 if ( $this->mAllowGenerator && isset( $this->mParams['generator'] ) ) {
 268                         return 'generator';
 269                 }
 270                 if ( isset( $this->mParams['titles'] ) ) {
 271                         return 'titles';
 272                 }
 273                 if ( isset( $this->mParams['pageids'] ) ) {
 274                         return 'pageids';
 275                 }
 276                 if ( isset( $this->mParams['revids'] ) ) {
 277                         return 'revids';
 278                 }
 279
 280                 return null;
 281         }
 282
 283         /**
 284          * Request an additional field from the page table.
 285          * Must be called before execute()
 286          * @param string $fieldName Field name
 287          */
 288         public function requestField( $fieldName ) {
 289                 $this->mRequestedPageFields[$fieldName] = null;
 290         }
 291
 292         /**
 293          * Get the value of a custom field previously requested through
 294          * requestField()
 295          * @param string $fieldName Field name
 296          * @return mixed Field value
 297          */
 298         public function getCustomField( $fieldName ) {
 299                 return $this->mRequestedPageFields[$fieldName];
 300         }
 301
 302         /**
 303          * Get the fields that have to be queried from the page table:
 304          * the ones requested through requestField() and a few basic ones
 305          * we always need
 306          * @return array Array of field names
 307          */
 308         public function getPageTableFields() {
 309                 // Ensure we get minimum required fields
 310                 // DON'T change this order
 311                 $pageFlds = [
 312                         'page_namespace' => null,
 313                         'page_title' => null,
 314                         'page_id' => null,
 315                 ];
 316
 317                 if ( $this->mResolveRedirects ) {
 318                         $pageFlds['page_is_redirect'] = null;
 319                 }
 320
 321                 if ( $this->getConfig()->get( 'ContentHandlerUseDB' ) ) {
 322                         $pageFlds['page_content_model'] = null;
 323                 }
 324
 325                 if ( $this->getConfig()->get( 'PageLanguageUseDB' ) ) {
 326                         $pageFlds['page_lang'] = null;
 327                 }
 328
 329                 foreach ( LinkCache::getSelectFields() as $field ) {
 330                         $pageFlds[$field] = null;
 331                 }
 332
 333                 $pageFlds = array_merge( $pageFlds, $this->mRequestedPageFields );
 334
 335                 return array_keys( $pageFlds );
 336         }
 337
 338         /**
 339          * Returns an array [ns][dbkey] => page_id for all requested titles.
 340          * page_id is a unique negative number in case title was not found.
 341          * Invalid titles will also have negative page IDs and will be in namespace 0
 342          * @return array
 343          */
 344         public function getAllTitlesByNamespace() {
 345                 return $this->mAllPages;
 346         }
 347
 348         /**
 349          * All Title objects provided.
 350          * @return Title[]
 351          */
 352         public function getTitles() {
 353                 return $this->mTitles;
 354         }
 355
 356         /**
 357          * Returns the number of unique pages (not revisions) in the set.
 358          * @return int
 359          */
 360         public function getTitleCount() {
 361                 return count( $this->mTitles );
 362         }
 363
 364         /**
 365          * Returns an array [ns][dbkey] => page_id for all good titles.
 366          * @return array
 367          */
 368         public function getGoodTitlesByNamespace() {
 369                 return $this->mGoodPages;
 370         }
 371
 372         /**
 373          * Title objects that were found in the database.
 374          * @return Title[] Array page_id (int) => Title (obj)
 375          */
 376         public function getGoodTitles() {
 377                 return $this->mGoodTitles;
 378         }
 379
 380         /**
 381          * Returns the number of found unique pages (not revisions) in the set.
 382          * @return int
 383          */
 384         public function getGoodTitleCount() {
 385                 return count( $this->mGoodTitles );
 386         }
 387
 388         /**
 389          * Returns an array [ns][dbkey] => fake_page_id for all missing titles.
 390          * fake_page_id is a unique negative number.
 391          * @return array
 392          */
 393         public function getMissingTitlesByNamespace() {
 394                 return $this->mMissingPages;
 395         }
 396
 397         /**
 398          * Title objects that were NOT found in the database.
 399          * The array's index will be negative for each item
 400          * @return Title[]
 401          */
 402         public function getMissingTitles() {
 403                 return $this->mMissingTitles;
 404         }
 405
 406         /**
 407          * Returns an array [ns][dbkey] => page_id for all good and missing titles.
 408          * @return array
 409          */
 410         public function getGoodAndMissingTitlesByNamespace() {
 411                 return $this->mGoodAndMissingPages;
 412         }
 413
 414         /**
 415          * Title objects for good and missing titles.
 416          * @return array
 417          */
 418         public function getGoodAndMissingTitles() {
 419                 return $this->mGoodTitles + $this->mMissingTitles;
 420         }
 421
 422         /**
 423          * Titles that were deemed invalid by Title::newFromText()
 424          * The array's index will be unique and negative for each item
 425          * @return array[] Array of arrays with 'title' and 'invalidreason' properties
 426          */
 427         public function getInvalidTitlesAndReasons() {
 428                 return $this->mInvalidTitles;
 429         }
 430
 431         /**
 432          * Page IDs that were not found in the database
 433          * @return array Array of page IDs
 434          */
 435         public function getMissingPageIDs() {
 436                 return $this->mMissingPageIDs;
 437         }
 438
 439         /**
 440          * Get a list of redirect resolutions - maps a title to its redirect
 441          * target, as an array of output-ready arrays
 442          * @return Title[]
 443          */
 444         public function getRedirectTitles() {
 445                 return $this->mRedirectTitles;
 446         }
 447
 448         /**
 449          * Get a list of redirect resolutions - maps a title to its redirect
 450          * target. Includes generator data for redirect source when available.
 451          * @param ApiResult|null $result
 452          * @return array Array of prefixed_title (string) => Title object
 453          * @since 1.21
 454          */
 455         public function getRedirectTitlesAsResult( $result = null ) {
 456                 $values = [];
 457                 foreach ( $this->getRedirectTitles() as $titleStrFrom => $titleTo ) {
 458                         $r = [
 459                                 'from' => strval( $titleStrFrom ),
 460                                 'to' => $titleTo->getPrefixedText(),
 461                         ];
 462                         if ( $titleTo->hasFragment() ) {
 463                                 $r['tofragment'] = $titleTo->getFragment();
 464                         }
 465                         if ( $titleTo->isExternal() ) {
 466                                 $r['tointerwiki'] = $titleTo->getInterwiki();
 467                         }
 468                         if ( isset( $this->mResolvedRedirectTitles[$titleStrFrom] ) ) {
 469                                 $titleFrom = $this->mResolvedRedirectTitles[$titleStrFrom];
 470                                 $ns = $titleFrom->getNamespace();
 471                                 $dbkey = $titleFrom->getDBkey();
 472                                 if ( isset( $this->mGeneratorData[$ns][$dbkey] ) ) {
 473                                         $r = array_merge( $this->mGeneratorData[$ns][$dbkey], $r );
 474                                 }
 475                         }
 476
 477                         $values[] = $r;
 478                 }
 479                 if ( !empty( $values ) && $result ) {
 480                         ApiResult::setIndexedTagName( $values, 'r' );
 481                 }
 482
 483                 return $values;
 484         }
 485
 486         /**
 487          * Get a list of title normalizations - maps a title to its normalized
 488          * version.
 489          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 490          */
 491         public function getNormalizedTitles() {
 492                 return $this->mNormalizedTitles;
 493         }
 494
 495         /**
 496          * Get a list of title normalizations - maps a title to its normalized
 497          * version in the form of result array.
 498          * @param ApiResult|null $result
 499          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 500          * @since 1.21
 501          */
 502         public function getNormalizedTitlesAsResult( $result = null ) {
 503                 $values = [];
 504                 $contLang = MediaWikiServices::getInstance()->getContentLanguage();
 505                 foreach ( $this->getNormalizedTitles() as $rawTitleStr => $titleStr ) {
 506                         $encode = $contLang->normalize( $rawTitleStr ) !== $rawTitleStr;
 507                         $values[] = [
 508                                 'fromencoded' => $encode,
 509                                 'from' => $encode ? rawurlencode( $rawTitleStr ) : $rawTitleStr,
 510                                 'to' => $titleStr
 511                         ];
 512                 }
 513                 if ( !empty( $values ) && $result ) {
 514                         ApiResult::setIndexedTagName( $values, 'n' );
 515                 }
 516
 517                 return $values;
 518         }
 519
 520         /**
 521          * Get a list of title conversions - maps a title to its converted
 522          * version.
 523          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 524          */
 525         public function getConvertedTitles() {
 526                 return $this->mConvertedTitles;
 527         }
 528
 529         /**
 530          * Get a list of title conversions - maps a title to its converted
 531          * version as a result array.
 532          * @param ApiResult|null $result
 533          * @return array Array of (from, to) strings
 534          * @since 1.21
 535          */
 536         public function getConvertedTitlesAsResult( $result = null ) {
 537                 $values = [];
 538                 foreach ( $this->getConvertedTitles() as $rawTitleStr => $titleStr ) {
 539                         $values[] = [
 540                                 'from' => $rawTitleStr,
 541                                 'to' => $titleStr
 542                         ];
 543                 }
 544                 if ( !empty( $values ) && $result ) {
 545                         ApiResult::setIndexedTagName( $values, 'c' );
 546                 }
 547
 548                 return $values;
 549         }
 550
 551         /**
 552          * Get a list of interwiki titles - maps a title to its interwiki
 553          * prefix.
 554          * @return array Array of raw_prefixed_title (string) => interwiki_prefix (string)
 555          */
 556         public function getInterwikiTitles() {
 557                 return $this->mInterwikiTitles;
 558         }
 559
 560         /**
 561          * Get a list of interwiki titles - maps a title to its interwiki
 562          * prefix as result.
 563          * @param ApiResult|null $result
 564          * @param bool $iwUrl
 565          * @return array Array of raw_prefixed_title (string) => interwiki_prefix (string)
 566          * @since 1.21
 567          */
 568         public function getInterwikiTitlesAsResult( $result = null, $iwUrl = false ) {
 569                 $values = [];
 570                 foreach ( $this->getInterwikiTitles() as $rawTitleStr => $interwikiStr ) {
 571                         $item = [
 572                                 'title' => $rawTitleStr,
 573                                 'iw' => $interwikiStr,
 574                         ];
 575                         if ( $iwUrl ) {
 576                                 $title = Title::newFromText( $rawTitleStr );
 577                                 $item['url'] = $title->getFullURL( '', false, PROTO_CURRENT );
 578                         }
 579                         $values[] = $item;
 580                 }
 581                 if ( !empty( $values ) && $result ) {
 582                         ApiResult::setIndexedTagName( $values, 'i' );
 583                 }
 584
 585                 return $values;
 586         }
 587
 588         /**
 589          * Get an array of invalid/special/missing titles.
 590          *
 591          * @param array $invalidChecks List of types of invalid titles to include.
 592          *   Recognized values are:
 593          *   - invalidTitles: Titles and reasons from $this->getInvalidTitlesAndReasons()
 594          *   - special: Titles from $this->getSpecialTitles()
 595          *   - missingIds: ids from $this->getMissingPageIDs()
 596          *   - missingRevIds: ids from $this->getMissingRevisionIDs()
 597          *   - missingTitles: Titles from $this->getMissingTitles()
 598          *   - interwikiTitles: Titles from $this->getInterwikiTitlesAsResult()
 599          * @return array Array suitable for inclusion in the response
 600          * @since 1.23
 601          */
 602         public function getInvalidTitlesAndRevisions( $invalidChecks = [ 'invalidTitles',
 603                 'special', 'missingIds', 'missingRevIds', 'missingTitles', 'interwikiTitles' ]
 604         ) {
 605                 $result = [];
 606                 if ( in_array( 'invalidTitles', $invalidChecks ) ) {
 607                         self::addValues( $result, $this->getInvalidTitlesAndReasons(), [ 'invalid' ] );
 608                 }
 609                 if ( in_array( 'special', $invalidChecks ) ) {
 610                         $known = [];
 611                         $unknown = [];
 612                         foreach ( $this->getSpecialTitles() as $title ) {
 613                                 if ( $title->isKnown() ) {
 614                                         $known[] = $title;
 615                                 } else {
 616                                         $unknown[] = $title;
 617                                 }
 618                         }
 619                         self::addValues( $result, $unknown, [ 'special', 'missing' ] );
 620                         self::addValues( $result, $known, [ 'special' ] );
 621                 }
 622                 if ( in_array( 'missingIds', $invalidChecks ) ) {
 623                         self::addValues( $result, $this->getMissingPageIDs(), [ 'missing' ], 'pageid' );
 624                 }
 625                 if ( in_array( 'missingRevIds', $invalidChecks ) ) {
 626                         self::addValues( $result, $this->getMissingRevisionIDs(), [ 'missing' ], 'revid' );
 627                 }
 628                 if ( in_array( 'missingTitles', $invalidChecks ) ) {
 629                         $known = [];
 630                         $unknown = [];
 631                         foreach ( $this->getMissingTitles() as $title ) {
 632                                 if ( $title->isKnown() ) {
 633                                         $known[] = $title;
 634                                 } else {
 635                                         $unknown[] = $title;
 636                                 }
 637                         }
 638                         self::addValues( $result, $unknown, [ 'missing' ] );
 639                         self::addValues( $result, $known, [ 'missing', 'known' ] );
 640                 }
 641                 if ( in_array( 'interwikiTitles', $invalidChecks ) ) {
 642                         self::addValues( $result, $this->getInterwikiTitlesAsResult() );
 643                 }
 644
 645                 return $result;
 646         }
 647
 648         /**
 649          * Get the list of valid revision IDs (requested with the revids= parameter)
 650          * @return array Array of revID (int) => pageID (int)
 651          */
 652         public function getRevisionIDs() {
 653                 return $this->mGoodRevIDs;
 654         }
 655
 656         /**
 657          * Get the list of non-deleted revision IDs (requested with the revids= parameter)
 658          * @return array Array of revID (int) => pageID (int)
 659          */
 660         public function getLiveRevisionIDs() {
 661                 return $this->mLiveRevIDs;
 662         }
 663
 664         /**
 665          * Get the list of revision IDs that were associated with deleted titles.
 666          * @return array Array of revID (int) => pageID (int)
 667          */
 668         public function getDeletedRevisionIDs() {
 669                 return $this->mDeletedRevIDs;
 670         }
 671
 672         /**
 673          * Revision IDs that were not found in the database
 674          * @return array Array of revision IDs
 675          */
 676         public function getMissingRevisionIDs() {
 677                 return $this->mMissingRevIDs;
 678         }
 679
 680         /**
 681          * Revision IDs that were not found in the database as result array.
 682          * @param ApiResult|null $result
 683          * @return array Array of revision IDs
 684          * @since 1.21
 685          */
 686         public function getMissingRevisionIDsAsResult( $result = null ) {
 687                 $values = [];
 688                 foreach ( $this->getMissingRevisionIDs() as $revid ) {
 689                         $values[$revid] = [
 690                                 'revid' => $revid
 691                         ];
 692                 }
 693                 if ( !empty( $values ) && $result ) {
 694                         ApiResult::setIndexedTagName( $values, 'rev' );
 695                 }
 696
 697                 return $values;
 698         }
 699
 700         /**
 701          * Get the list of titles with negative namespace
 702          * @return Title[]
 703          */
 704         public function getSpecialTitles() {
 705                 return $this->mSpecialTitles;
 706         }
 707
 708         /**
 709          * Returns the number of revisions (requested with revids= parameter).
 710          * @return int Number of revisions.
 711          */
 712         public function getRevisionCount() {
 713                 return count( $this->getRevisionIDs() );
 714         }
 715
 716         /**
 717          * Populate this PageSet from a list of Titles
 718          * @param array $titles Array of Title objects
 719          */
 720         public function populateFromTitles( $titles ) {
 721                 $this->initFromTitles( $titles );
 722         }
 723
 724         /**
 725          * Populate this PageSet from a list of page IDs
 726          * @param array $pageIDs Array of page IDs
 727          */
 728         public function populateFromPageIDs( $pageIDs ) {
 729                 $this->initFromPageIds( $pageIDs );
 730         }
 731
 732         /**
 733          * Populate this PageSet from a rowset returned from the database
 734          *
 735          * Note that the query result must include the columns returned by
 736          * $this->getPageTableFields().
 737          *
 738          * @param IDatabase $db
 739          * @param IResultWrapper $queryResult
 740          */
 741         public function populateFromQueryResult( $db, $queryResult ) {
 742                 $this->initFromQueryResult( $queryResult );
 743         }
 744
 745         /**
 746          * Populate this PageSet from a list of revision IDs
 747          * @param array $revIDs Array of revision IDs
 748          */
 749         public function populateFromRevisionIDs( $revIDs ) {
 750                 $this->initFromRevIDs( $revIDs );
 751         }
 752
 753         /**
 754          * Extract all requested fields from the row received from the database
 755          * @param stdClass $row Result row
 756          */
 757         public function processDbRow( $row ) {
 758                 // Store Title object in various data structures
 759                 $title = Title::newFromRow( $row );
 760
 761                 $linkCache = MediaWikiServices::getInstance()->getLinkCache();
 762                 $linkCache->addGoodLinkObjFromRow( $title, $row );
 763
 764                 $pageId = (int)$row->page_id;
 765                 $this->mAllPages[$row->page_namespace][$row->page_title] = $pageId;
 766                 $this->mTitles[] = $title;
 767
 768                 if ( $this->mResolveRedirects && $row->page_is_redirect == '1' ) {
 769                         $this->mPendingRedirectIDs[$pageId] = $title;
 770                 } else {
 771                         $this->mGoodPages[$row->page_namespace][$row->page_title] = $pageId;
 772                         $this->mGoodAndMissingPages[$row->page_namespace][$row->page_title] = $pageId;
 773                         $this->mGoodTitles[$pageId] = $title;
 774                 }
 775
 776                 foreach ( $this->mRequestedPageFields as $fieldName => &$fieldValues ) {
 777                         $fieldValues[$pageId] = $row->$fieldName;
 778                 }
 779         }
 780
 781         /**
 782          * This method populates internal variables with page information
 783          * based on the given array of title strings.
 784          *
 785          * Steps:
 786          * #1 For each title, get data from `page` table
 787          * #2 If page was not found in the DB, store it as missing
 788          *
 789          * Additionally, when resolving redirects:
 790          * #3 If no more redirects left, stop.
 791          * #4 For each redirect, get its target from the `redirect` table.
 792          * #5 Substitute the original LinkBatch object with the new list
 793          * #6 Repeat from step #1
 794          *
 795          * @param array $titles Array of Title objects or strings
 796          */
 797         private function initFromTitles( $titles ) {
 798                 // Get validated and normalized title objects
 799                 $linkBatch = $this->processTitlesArray( $titles );
 800                 if ( $linkBatch->isEmpty() ) {
 801                         // There might be special-page redirects
 802                         $this->resolvePendingRedirects();
 803                         return;
 804                 }
 805
 806                 $db = $this->getDB();
 807                 $set = $linkBatch->constructSet( 'page', $db );
 808
 809                 // Get pageIDs data from the `page` table
 810                 $res = $db->select( 'page', $this->getPageTableFields(), $set,
 811                         __METHOD__ );
 812
 813                 // Hack: get the ns:titles stored in [ ns => [ titles ] ] format
 814                 $this->initFromQueryResult( $res, $linkBatch->data, true ); // process Titles
 815
 816                 // Resolve any found redirects
 817                 $this->resolvePendingRedirects();
 818         }
 819
 820         /**
 821          * Does the same as initFromTitles(), but is based on page IDs instead
 822          * @param array $pageids Array of page IDs
 823          * @param bool $filterIds Whether the IDs need filtering
 824          */
 825         private function initFromPageIds( $pageids, $filterIds = true ) {
 826                 if ( !$pageids ) {
 827                         return;
 828                 }
 829
 830                 $pageids = array_map( 'intval', $pageids ); // paranoia
 831                 $remaining = array_flip( $pageids );
 832
 833                 if ( $filterIds ) {
 834                         $pageids = $this->filterIDs( [ [ 'page', 'page_id' ] ], $pageids );
 835                 }
 836
 837                 $res = null;
 838                 if ( !empty( $pageids ) ) {
 839                         $set = [
 840                                 'page_id' => $pageids
 841                         ];
 842                         $db = $this->getDB();
 843
 844                         // Get pageIDs data from the `page` table
 845                         $res = $db->select( 'page', $this->getPageTableFields(), $set,
 846                                 __METHOD__ );
 847                 }
 848
 849                 $this->initFromQueryResult( $res, $remaining, false ); // process PageIDs
 850
 851                 // Resolve any found redirects
 852                 $this->resolvePendingRedirects();
 853         }
 854
 855         /**
 856          * Iterate through the result of the query on 'page' table,
 857          * and for each row create and store title object and save any extra fields requested.
 858          * @param IResultWrapper $res DB Query result
 859          * @param array $remaining Array of either pageID or ns/title elements (optional).
 860          *        If given, any missing items will go to $mMissingPageIDs and $mMissingTitles
 861          * @param bool $processTitles Must be provided together with $remaining.
 862          *        If true, treat $remaining as an array of [ns][title]
 863          *        If false, treat it as an array of [pageIDs]
 864          */
 865         private function initFromQueryResult( $res, &$remaining = null, $processTitles = null ) {
 866                 if ( !is_null( $remaining ) && is_null( $processTitles ) ) {
 867                         ApiBase::dieDebug( __METHOD__, 'Missing $processTitles parameter when $remaining is provided' );
 868                 }
 869
 870                 $nsInfo = MediaWikiServices::getInstance()->getNamespaceInfo();
 871
 872                 $usernames = [];
 873                 if ( $res ) {
 874                         foreach ( $res as $row ) {
 875                                 $pageId = (int)$row->page_id;
 876
 877                                 // Remove found page from the list of remaining items
 878                                 if ( isset( $remaining ) ) {
 879                                         if ( $processTitles ) {
 880                                                 unset( $remaining[$row->page_namespace][$row->page_title] );
 881                                         } else {
 882                                                 unset( $remaining[$pageId] );
 883                                         }
 884                                 }
 885
 886                                 // Store any extra fields requested by modules
 887                                 $this->processDbRow( $row );
 888
 889                                 // Need gender information
 890                                 if ( $nsInfo->hasGenderDistinction( $row->page_namespace ) ) {
 891                                         $usernames[] = $row->page_title;
 892                                 }
 893                         }
 894                 }
 895
 896                 if ( isset( $remaining ) ) {
 897                         // Any items left in the $remaining list are added as missing
 898                         if ( $processTitles ) {
 899                                 // The remaining titles in $remaining are non-existent pages
 900                                 $linkCache = MediaWikiServices::getInstance()->getLinkCache();
 901                                 foreach ( $remaining as $ns => $dbkeys ) {
 902                                         foreach ( array_keys( $dbkeys ) as $dbkey ) {
 903                                                 $title = Title::makeTitle( $ns, $dbkey );
 904                                                 $linkCache->addBadLinkObj( $title );
 905                                                 $this->mAllPages[$ns][$dbkey] = $this->mFakePageId;
 906                                                 $this->mMissingPages[$ns][$dbkey] = $this->mFakePageId;
 907                                                 $this->mGoodAndMissingPages[$ns][$dbkey] = $this->mFakePageId;
 908                                                 $this->mMissingTitles[$this->mFakePageId] = $title;
 909                                                 $this->mFakePageId--;
 910                                                 $this->mTitles[] = $title;
 911
 912                                                 // need gender information
 913                                                 if ( $nsInfo->hasGenderDistinction( $ns ) ) {
 914                                                         $usernames[] = $dbkey;
 915                                                 }
 916                                         }
 917                                 }
 918                         } else {
 919                                 // The remaining pageids do not exist
 920                                 if ( !$this->mMissingPageIDs ) {
 921                                         $this->mMissingPageIDs = array_keys( $remaining );
 922                                 } else {
 923                                         $this->mMissingPageIDs = array_merge( $this->mMissingPageIDs, array_keys( $remaining ) );
 924                                 }
 925                         }
 926                 }
 927
 928                 // Get gender information
 929                 $genderCache = MediaWikiServices::getInstance()->getGenderCache();
 930                 $genderCache->doQuery( $usernames, __METHOD__ );
 931         }
 932
 933         /**
 934          * Does the same as initFromTitles(), but is based on revision IDs
 935          * instead
 936          * @param array $revids Array of revision IDs
 937          */
 938         private function initFromRevIDs( $revids ) {
 939                 if ( !$revids ) {
 940                         return;
 941                 }
 942
 943                 $revids = array_map( 'intval', $revids ); // paranoia
 944                 $db = $this->getDB();
 945                 $pageids = [];
 946                 $remaining = array_flip( $revids );
 947
 948                 $revids = $this->filterIDs( [ [ 'revision', 'rev_id' ], [ 'archive', 'ar_rev_id' ] ], $revids );
 949                 $goodRemaining = array_flip( $revids );
 950
 951                 if ( $revids ) {
 952                         $tables = [ 'revision', 'page' ];
 953                         $fields = [ 'rev_id', 'rev_page' ];
 954                         $where = [ 'rev_id' => $revids, 'rev_page = page_id' ];
 955
 956                         // Get pageIDs data from the `page` table
 957                         $res = $db->select( $tables, $fields, $where, __METHOD__ );
 958                         foreach ( $res as $row ) {
 959                                 $revid = (int)$row->rev_id;
 960                                 $pageid = (int)$row->rev_page;
 961                                 $this->mGoodRevIDs[$revid] = $pageid;
 962                                 $this->mLiveRevIDs[$revid] = $pageid;
 963                                 $pageids[$pageid] = '';
 964                                 unset( $remaining[$revid] );
 965                                 unset( $goodRemaining[$revid] );
 966                         }
 967                 }
 968
 969                 // Populate all the page information
 970                 $this->initFromPageIds( array_keys( $pageids ), false );
 971
 972                 // If the user can see deleted revisions, pull out the corresponding
 973                 // titles from the archive table and include them too. We ignore
 974                 // ar_page_id because deleted revisions are tied by title, not page_id.
 975                 if ( $goodRemaining &&
 976                          $this->getPermissionManager()->userHasRight( $this->getUser(), 'deletedhistory' ) ) {
 977                         $tables = [ 'archive' ];
 978                         $fields = [ 'ar_rev_id', 'ar_namespace', 'ar_title' ];
 979                         $where = [ 'ar_rev_id' => array_keys( $goodRemaining ) ];
 980
 981                         $res = $db->select( $tables, $fields, $where, __METHOD__ );
 982                         $titles = [];
 983                         foreach ( $res as $row ) {
 984                                 $revid = (int)$row->ar_rev_id;
 985                                 $titles[$revid] = Title::makeTitle( $row->ar_namespace, $row->ar_title );
 986                                 unset( $remaining[$revid] );
 987                         }
 988
 989                         $this->initFromTitles( $titles );
 990
 991                         foreach ( $titles as $revid => $title ) {
 992                                 $ns = $title->getNamespace();
 993                                 $dbkey = $title->getDBkey();
 994
 995                                 // Handle converted titles
 996                                 if ( !isset( $this->mAllPages[$ns][$dbkey] ) &&
 997                                         isset( $this->mConvertedTitles[$title->getPrefixedText()] )
 998                                 ) {
 999                                         $title = Title::newFromText( $this->mConvertedTitles[$title->getPrefixedText()] );
1000                                         $ns = $title->getNamespace();
1001                                         $dbkey = $title->getDBkey();
1002                                 }
1003
1004                                 if ( isset( $this->mAllPages[$ns][$dbkey] ) ) {
1005                                         $this->mGoodRevIDs[$revid] = $this->mAllPages[$ns][$dbkey];
1006                                         $this->mDeletedRevIDs[$revid] = $this->mAllPages[$ns][$dbkey];
1007                                 } else {
1008                                         $remaining[$revid] = true;
1009                                 }
1010                         }
1011                 }
1012
1013                 $this->mMissingRevIDs = array_keys( $remaining );
1014         }
1015
1016         /**
1017          * Resolve any redirects in the result if redirect resolution was
1018          * requested. This function is called repeatedly until all redirects
1019          * have been resolved.
1020          */
1021         private function resolvePendingRedirects() {
1022                 if ( $this->mResolveRedirects ) {
1023                         $db = $this->getDB();
1024                         $pageFlds = $this->getPageTableFields();
1025
1026                         // Repeat until all redirects have been resolved
1027                         // The infinite loop is prevented by keeping all known pages in $this->mAllPages
1028                         while ( $this->mPendingRedirectIDs || $this->mPendingRedirectSpecialPages ) {
1029                                 // Resolve redirects by querying the pagelinks table, and repeat the process
1030                                 // Create a new linkBatch object for the next pass
1031                                 $linkBatch = $this->getRedirectTargets();
1032
1033                                 if ( $linkBatch->isEmpty() ) {
1034                                         break;
1035                                 }
1036
1037                                 $set = $linkBatch->constructSet( 'page', $db );
1038                                 if ( $set === false ) {
1039                                         break;
1040                                 }
1041
1042                                 // Get pageIDs data from the `page` table
1043                                 $res = $db->select( 'page', $pageFlds, $set, __METHOD__ );
1044
1045                                 // Hack: get the ns:titles stored in [ns => array(titles)] format
1046                                 $this->initFromQueryResult( $res, $linkBatch->data, true );
1047                         }
1048                 }
1049         }
1050
1051         /**
1052          * Get the targets of the pending redirects from the database
1053          *
1054          * Also creates entries in the redirect table for redirects that don't
1055          * have one.
1056          * @return LinkBatch
1057          */
1058         private function getRedirectTargets() {
1059                 $titlesToResolve = [];
1060                 $db = $this->getDB();
1061
1062                 if ( $this->mPendingRedirectIDs ) {
1063                         $res = $db->select(
1064                                 'redirect',
1065                                 [
1066                                         'rd_from',
1067                                         'rd_namespace',
1068                                         'rd_fragment',
1069                                         'rd_interwiki',
1070                                         'rd_title'
1071                                 ], [ 'rd_from' => array_keys( $this->mPendingRedirectIDs ) ],
1072                                         __METHOD__
1073                                 );
1074                         foreach ( $res as $row ) {
1075                                 $rdfrom = (int)$row->rd_from;
1076                                 $from = $this->mPendingRedirectIDs[$rdfrom]->getPrefixedText();
1077                                 $to = Title::makeTitle(
1078                                         $row->rd_namespace,
1079                                         $row->rd_title,
1080                                         $row->rd_fragment,
1081                                         $row->rd_interwiki
1082                                 );
1083                                 $this->mResolvedRedirectTitles[$from] = $this->mPendingRedirectIDs[$rdfrom];
1084                                 unset( $this->mPendingRedirectIDs[$rdfrom] );
1085                                 if ( $to->isExternal() ) {
1086                                         $this->mInterwikiTitles[$to->getPrefixedText()] = $to->getInterwiki();
1087                                 } elseif ( !isset( $this->mAllPages[$to->getNamespace()][$to->getDBkey()] ) ) {
1088                                         $titlesToResolve[] = $to;
1089                                 }
1090                                 $this->mRedirectTitles[$from] = $to;
1091                         }
1092
1093                         if ( $this->mPendingRedirectIDs ) {
1094                                 // We found pages that aren't in the redirect table
1095                                 // Add them
1096                                 foreach ( $this->mPendingRedirectIDs as $id => $title ) {
1097                                         $page = WikiPage::factory( $title );
1098                                         $rt = $page->insertRedirect();
1099                                         if ( !$rt ) {
1100                                                 // What the hell. Let's just ignore this
1101                                                 continue;
1102                                         }
1103                                         if ( $rt->isExternal() ) {
1104                                                 $this->mInterwikiTitles[$rt->getPrefixedText()] = $rt->getInterwiki();
1105                                         } elseif ( !isset( $this->mAllPages[$rt->getNamespace()][$rt->getDBkey()] ) ) {
1106                                                 $titlesToResolve[] = $rt;
1107                                         }
1108                                         $from = $title->getPrefixedText();
1109                                         $this->mResolvedRedirectTitles[$from] = $title;
1110                                         $this->mRedirectTitles[$from] = $rt;
1111                                         unset( $this->mPendingRedirectIDs[$id] );
1112                                 }
1113                         }
1114                 }
1115
1116                 if ( $this->mPendingRedirectSpecialPages ) {
1117                         foreach ( $this->mPendingRedirectSpecialPages as $key => list( $from, $to ) ) {
1118                                 $fromKey = $from->getPrefixedText();
1119                                 $this->mResolvedRedirectTitles[$fromKey] = $from;
1120                                 $this->mRedirectTitles[$fromKey] = $to;
1121                                 if ( $to->isExternal() ) {
1122                                         $this->mInterwikiTitles[$to->getPrefixedText()] = $to->getInterwiki();
1123                                 } elseif ( !isset( $this->mAllPages[$to->getNamespace()][$to->getDBkey()] ) ) {
1124                                         $titlesToResolve[] = $to;
1125                                 }
1126                         }
1127                         $this->mPendingRedirectSpecialPages = [];
1128
1129                         // Set private caching since we don't know what criteria the
1130                         // special pages used to decide on these redirects.
1131                         $this->mCacheMode = 'private';
1132                 }
1133
1134                 return $this->processTitlesArray( $titlesToResolve );
1135         }
1136
1137         /**
1138          * Get the cache mode for the data generated by this module.
1139          * All PageSet users should take into account whether this returns a more-restrictive
1140          * cache mode than the using module itself. For possible return values and other
1141          * details about cache modes, see ApiMain::setCacheMode()
1142          *
1143          * Public caching will only be allowed if *all* the modules that supply
1144          * data for a given request return a cache mode of public.
1145          *
1146          * @param array|null $params
1147          * @return string
1148          * @since 1.21
1149          */
1150         public function getCacheMode( $params = null ) {
1151                 return $this->mCacheMode;
1152         }
1153
1154         /**
1155          * Given an array of title strings, convert them into Title objects.
1156          * Alternatively, an array of Title objects may be given.
1157          * This method validates access rights for the title,
1158          * and appends normalization values to the output.
1159          *
1160          * @param array $titles Array of Title objects or strings
1161          * @return LinkBatch
1162          */
1163         private function processTitlesArray( $titles ) {
1164                 $usernames = [];
1165                 $linkBatch = new LinkBatch();
1166                 $services = MediaWikiServices::getInstance();
1167                 $contLang = $services->getContentLanguage();
1168
1169                 foreach ( $titles as $title ) {
1170                         if ( is_string( $title ) ) {
1171                                 try {
1172                                         $titleObj = Title::newFromTextThrow( $title, $this->mDefaultNamespace );
1173                                 } catch ( MalformedTitleException $ex ) {
1174                                         // Handle invalid titles gracefully
1175                                         if ( !isset( $this->mAllPages[0][$title] ) ) {
1176                                                 $this->mAllPages[0][$title] = $this->mFakePageId;
1177                                                 $this->mInvalidTitles[$this->mFakePageId] = [
1178                                                         'title' => $title,
1179                                                         'invalidreason' => $this->getErrorFormatter()->formatException( $ex, [ 'bc' => true ] ),
1180                                                 ];
1181                                                 $this->mFakePageId--;
1182                                         }
1183                                         continue; // There's nothing else we can do
1184                                 }
1185                         } else {
1186                                 $titleObj = $title;
1187                         }
1188                         $unconvertedTitle = $titleObj->getPrefixedText();
1189                         $titleWasConverted = false;
1190                         if ( $titleObj->isExternal() ) {
1191                                 // This title is an interwiki link.
1192                                 $this->mInterwikiTitles[$unconvertedTitle] = $titleObj->getInterwiki();
1193                         } else {
1194                                 // Variants checking
1195                                 if (
1196                                         $this->mConvertTitles && $contLang->hasVariants() && !$titleObj->exists()
1197                                 ) {
1198                                         // Language::findVariantLink will modify titleText and titleObj into
1199                                         // the canonical variant if possible
1200                                         $titleText = is_string( $title ) ? $title : $titleObj->getPrefixedText();
1201                                         $contLang->findVariantLink( $titleText, $titleObj );
1202                                         $titleWasConverted = $unconvertedTitle !== $titleObj->getPrefixedText();
1203                                 }
1204
1205                                 if ( $titleObj->getNamespace() < 0 ) {
1206                                         // Handle Special and Media pages
1207                                         $titleObj = $titleObj->fixSpecialName();
1208                                         $ns = $titleObj->getNamespace();
1209                                         $dbkey = $titleObj->getDBkey();
1210                                         if ( !isset( $this->mAllSpecials[$ns][$dbkey] ) ) {
1211                                                 $this->mAllSpecials[$ns][$dbkey] = $this->mFakePageId;
1212                                                 $target = null;
1213                                                 if ( $ns === NS_SPECIAL && $this->mResolveRedirects ) {
1214                                                         $spFactory = $services->getSpecialPageFactory();
1215                                                         $special = $spFactory->getPage( $dbkey );
1216                                                         if ( $special instanceof RedirectSpecialArticle ) {
1217                                                                 // Only RedirectSpecialArticle is intended to redirect to an article, other kinds of
1218                                                                 // RedirectSpecialPage are probably applying weird URL parameters we don't want to handle.
1219                                                                 $context = new DerivativeContext( $this );
1220                                                                 $context->setTitle( $titleObj );
1221                                                                 $context->setRequest( new FauxRequest );
1222                                                                 $special->setContext( $context );
1223                                                                 list( /* $alias */, $subpage ) = $spFactory->resolveAlias( $dbkey );
1224                                                                 $target = $special->getRedirect( $subpage );
1225                                                         }
1226                                                 }
1227                                                 if ( $target ) {
1228                                                         $this->mPendingRedirectSpecialPages[$dbkey] = [ $titleObj, $target ];
1229                                                 } else {
1230                                                         $this->mSpecialTitles[$this->mFakePageId] = $titleObj;
1231                                                         $this->mFakePageId--;
1232                                                 }
1233                                         }
1234                                 } else {
1235                                         // Regular page
1236                                         $linkBatch->addObj( $titleObj );
1237                                 }
1238                         }
1239
1240                         // Make sure we remember the original title that was
1241                         // given to us. This way the caller can correlate new
1242                         // titles with the originally requested when e.g. the
1243                         // namespace is localized or the capitalization is
1244                         // different
1245                         if ( $titleWasConverted ) {
1246                                 $this->mConvertedTitles[$unconvertedTitle] = $titleObj->getPrefixedText();
1247                                 // In this case the page can't be Special.
1248                                 if ( is_string( $title ) && $title !== $unconvertedTitle ) {
1249                                         $this->mNormalizedTitles[$title] = $unconvertedTitle;
1250                                 }
1251                         } elseif ( is_string( $title ) && $title !== $titleObj->getPrefixedText() ) {
1252                                 $this->mNormalizedTitles[$title] = $titleObj->getPrefixedText();
1253                         }
1254
1255                         // Need gender information
1256                         if (
1257                                 $services->getNamespaceInfo()->
1258                                         hasGenderDistinction( $titleObj->getNamespace() )
1259                         ) {
1260                                 $usernames[] = $titleObj->getText();
1261                         }
1262                 }
1263                 // Get gender information
1264                 $genderCache = $services->getGenderCache();
1265                 $genderCache->doQuery( $usernames, __METHOD__ );
1266
1267                 return $linkBatch;
1268         }
1269
1270         /**
1271          * Set data for a title.
1272          *
1273          * This data may be extracted into an ApiResult using
1274          * self::populateGeneratorData. This should generally be limited to
1275          * data that is likely to be particularly useful to end users rather than
1276          * just being a dump of everything returned in non-generator mode.
1277          *
1278          * Redirects here will *not* be followed, even if 'redirects' was
1279          * specified, since in the case of multiple redirects we can't know which
1280          * source's data to use on the target.
1281          *
1282          * @param Title $title
1283          * @param array $data
1284          */
1285         public function setGeneratorData( Title $title, array $data ) {
1286                 $ns = $title->getNamespace();
1287                 $dbkey = $title->getDBkey();
1288                 $this->mGeneratorData[$ns][$dbkey] = $data;
1289         }
1290
1291         /**
1292          * Controls how generator data about a redirect source is merged into
1293          * the generator data for the redirect target. When not set no data
1294          * is merged. Note that if multiple titles redirect to the same target
1295          * the order of operations is undefined.
1296          *
1297          * Example to include generated data from redirect in target, prefering
1298          * the data generated for the destination when there is a collision:
1299          * @code
1300          *   $pageSet->setRedirectMergePolicy( function( array $current, array $new ) {
1301          *       return $current + $new;
1302          *   } );
1303          * @endcode
1304          *
1305          * @param callable|null $callable Recieves two array arguments, first the
1306          *  generator data for the redirect target and second the generator data
1307          *  for the redirect source. Returns the resulting generator data to use
1308          *  for the redirect target.
1309          */
1310         public function setRedirectMergePolicy( $callable ) {
1311                 $this->mRedirectMergePolicy = $callable;
1312         }
1313
1314         /**
1315          * Populate the generator data for all titles in the result
1316          *
1317          * The page data may be inserted into an ApiResult object or into an
1318          * associative array. The $path parameter specifies the path within the
1319          * ApiResult or array to find the "pages" node.
1320          *
1321          * The "pages" node itself must be an associative array mapping the page ID
1322          * or fake page ID values returned by this pageset (see
1323          * self::getAllTitlesByNamespace() and self::getSpecialTitles()) to
1324          * associative arrays of page data. Each of those subarrays will have the
1325          * data from self::setGeneratorData() merged in.
1326          *
1327          * Data that was set by self::setGeneratorData() for pages not in the
1328          * "pages" node will be ignored.
1329          *
1330          * @param ApiResult|array &$result
1331          * @param array $path
1332          * @return bool Whether the data fit
1333          */
1334         public function populateGeneratorData( &$result, array $path = [] ) {
1335                 if ( $result instanceof ApiResult ) {
1336                         $data = $result->getResultData( $path );
1337                         if ( $data === null ) {
1338                                 return true;
1339                         }
1340                 } else {
1341                         $data = &$result;
1342                         foreach ( $path as $key ) {
1343                                 if ( !isset( $data[$key] ) ) {
1344                                         // Path isn't in $result, so nothing to add, so everything
1345                                         // "fits"
1346                                         return true;
1347                                 }
1348                                 $data = &$data[$key];
1349                         }
1350                 }
1351                 foreach ( $this->mGeneratorData as $ns => $dbkeys ) {
1352                         if ( $ns === NS_SPECIAL ) {
1353                                 $pages = [];
1354                                 foreach ( $this->mSpecialTitles as $id => $title ) {
1355                                         $pages[$title->getDBkey()] = $id;
1356                                 }
1357                         } else {
1358                                 if ( !isset( $this->mAllPages[$ns] ) ) {
1359                                         // No known titles in the whole namespace. Skip it.
1360                                         continue;
1361                                 }
1362                                 $pages = $this->mAllPages[$ns];
1363                         }
1364                         foreach ( $dbkeys as $dbkey => $genData ) {
1365                                 if ( !isset( $pages[$dbkey] ) ) {
1366                                         // Unknown title. Forget it.
1367                                         continue;
1368                                 }
1369                                 $pageId = $pages[$dbkey];
1370                                 if ( !isset( $data[$pageId] ) ) {
1371                                         // $pageId didn't make it into the result. Ignore it.
1372                                         continue;
1373                                 }
1374
1375                                 if ( $result instanceof ApiResult ) {
1376                                         $path2 = array_merge( $path, [ $pageId ] );
1377                                         foreach ( $genData as $key => $value ) {
1378                                                 if ( !$result->addValue( $path2, $key, $value ) ) {
1379                                                         return false;
1380                                                 }
1381                                         }
1382                                 } else {
1383                                         $data[$pageId] = array_merge( $data[$pageId], $genData );
1384                                 }
1385                         }
1386                 }
1387
1388                 // Merge data generated about redirect titles into the redirect destination
1389                 if ( $this->mRedirectMergePolicy ) {
1390                         foreach ( $this->mResolvedRedirectTitles as $titleFrom ) {
1391                                 $dest = $titleFrom;
1392                                 while ( isset( $this->mRedirectTitles[$dest->getPrefixedText()] ) ) {
1393                                         $dest = $this->mRedirectTitles[$dest->getPrefixedText()];
1394                                 }
1395                                 $fromNs = $titleFrom->getNamespace();
1396                                 $fromDBkey = $titleFrom->getDBkey();
1397                                 $toPageId = $dest->getArticleID();
1398                                 if ( isset( $data[$toPageId] ) &&
1399                                         isset( $this->mGeneratorData[$fromNs][$fromDBkey] )
1400                                 ) {
1401                                         // It is necessary to set both $data and add to $result, if an ApiResult,
1402                                         // to ensure multiple redirects to the same destination are all merged.
1403                                         $data[$toPageId] = call_user_func(
1404                                                 $this->mRedirectMergePolicy,
1405                                                 $data[$toPageId],
1406                                                 $this->mGeneratorData[$fromNs][$fromDBkey]
1407                                         );
1408                                         if ( $result instanceof ApiResult &&
1409                                                 !$result->addValue( $path, $toPageId, $data[$toPageId], ApiResult::OVERRIDE )
1410                                         ) {
1411                                                 return false;
1412                                         }
1413                                 }
1414                         }
1415                 }
1416
1417                 return true;
1418         }
1419
1420         /**
1421          * Get the database connection (read-only)
1422          * @return IDatabase
1423          */
1424         protected function getDB() {
1425                 return $this->mDbSource->getDB();
1426         }
1427
1428         public function getAllowedParams( $flags = 0 ) {
1429                 $result = [
1430                         'titles' => [
1431                                 ApiBase::PARAM_ISMULTI => true,
1432                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-titles',
1433                         ],
1434                         'pageids' => [
1435                                 ApiBase::PARAM_TYPE => 'integer',
1436                                 ApiBase::PARAM_ISMULTI => true,
1437                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-pageids',
1438                         ],
1439                         'revids' => [
1440                                 ApiBase::PARAM_TYPE => 'integer',
1441                                 ApiBase::PARAM_ISMULTI => true,
1442                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-revids',
1443                         ],
1444                         'generator' => [
1445                                 ApiBase::PARAM_TYPE => null,
1446                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-generator',
1447                                 ApiBase::PARAM_SUBMODULE_PARAM_PREFIX => 'g',
1448                         ],
1449                         'redirects' => [
1450                                 ApiBase::PARAM_DFLT => false,
1451                                 ApiBase::PARAM_HELP_MSG => $this->mAllowGenerator
1452                                         ? 'api-pageset-param-redirects-generator'
1453                                         : 'api-pageset-param-redirects-nogenerator',
1454                         ],
1455                         'converttitles' => [
1456                                 ApiBase::PARAM_DFLT => false,
1457                                 ApiBase::PARAM_HELP_MSG => [
1458                                         'api-pageset-param-converttitles',
1459                                         [ Message::listParam( LanguageConverter::$languagesWithVariants, 'text' ) ],
1460                                 ],
1461                         ],
1462                 ];
1463
1464                 if ( !$this->mAllowGenerator ) {
1465                         unset( $result['generator'] );
1466                 } elseif ( $flags & ApiBase::GET_VALUES_FOR_HELP ) {
1467                         $result['generator'][ApiBase::PARAM_TYPE] = 'submodule';
1468                         $result['generator'][ApiBase::PARAM_SUBMODULE_MAP] = $this->getGenerators();
1469                 }
1470
1471                 return $result;
1472         }
1473
1474         protected function handleParamNormalization( $paramName, $value, $rawValue ) {
1475                 parent::handleParamNormalization( $paramName, $value, $rawValue );
1476
1477                 if ( $paramName === 'titles' ) {
1478                         // For the 'titles' parameter, we want to split it like ApiBase would
1479                         // and add any changed titles to $this->mNormalizedTitles
1480                         $value = $this->explodeMultiValue( $value, self::LIMIT_SML2 + 1 );
1481                         $l = count( $value );
1482                         $rawValue = $this->explodeMultiValue( $rawValue, $l );
1483                         for ( $i = 0; $i < $l; $i++ ) {
1484                                 if ( $value[$i] !== $rawValue[$i] ) {
1485                                         $this->mNormalizedTitles[$rawValue[$i]] = $value[$i];
1486                                 }
1487                         }
1488                 }
1489         }
1490
1491         private static $generators = null;
1492
1493         /**
1494          * Get an array of all available generators
1495          * @return array
1496          */
1497         private function getGenerators() {
1498                 if ( self::$generators === null ) {
1499                         $query = $this->mDbSource;
1500                         if ( !( $query instanceof ApiQuery ) ) {
1501                                 // If the parent container of this pageset is not ApiQuery,
1502                                 // we must create it to get module manager
1503                                 $query = $this->getMain()->getModuleManager()->getModule( 'query' );
1504                         }
1505                         $gens = [];
1506                         $prefix = $query->getModulePath() . '+';
1507                         $mgr = $query->getModuleManager();
1508                         foreach ( $mgr->getNamesWithClasses() as $name => $class ) {
1509                                 if ( is_subclass_of( $class, ApiQueryGeneratorBase::class ) ) {
1510                                         $gens[$name] = $prefix . $name;
1511                                 }
1512                         }
1513                         ksort( $gens );
1514                         self::$generators = $gens;
1515                 }
1516
1517                 return self::$generators;
1518         }
1519 }