includes/api/ApiPageSet.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 24, 2006
   6  *
   7  * Copyright © 2006, 2013 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  */
  26
  27 /**
  28  * This class contains a list of pages that the client has requested.
  29  * Initially, when the client passes in titles=, pageids=, or revisions=
  30  * parameter, an instance of the ApiPageSet class will normalize titles,
  31  * determine if the pages/revisions exist, and prefetch any additional page
  32  * data requested.
  33  *
  34  * When a generator is used, the result of the generator will become the input
  35  * for the second instance of this class, and all subsequent actions will use
  36  * the second instance for all their work.
  37  *
  38  * @ingroup API
  39  * @since 1.21 derives from ApiBase instead of ApiQueryBase
  40  */
  41 class ApiPageSet extends ApiBase {
  42         /**
  43          * Constructor flag: The new instance of ApiPageSet will ignore the 'generator=' parameter
  44          * @since 1.21
  45          */
  46         const DISABLE_GENERATORS = 1;
  47
  48         private $mDbSource;
  49         private $mParams;
  50         private $mResolveRedirects;
  51         private $mConvertTitles;
  52         private $mAllowGenerator;
  53
  54         private $mAllPages = []; // [ns][dbkey] => page_id or negative when missing
  55         private $mTitles = [];
  56         private $mGoodAndMissingPages = []; // [ns][dbkey] => page_id or negative when missing
  57         private $mGoodPages = []; // [ns][dbkey] => page_id
  58         private $mGoodTitles = [];
  59         private $mMissingPages = []; // [ns][dbkey] => fake page_id
  60         private $mMissingTitles = [];
  61         /** @var array [fake_page_id] => [ 'title' => $title, 'invalidreason' => $reason ] */
  62         private $mInvalidTitles = [];
  63         private $mMissingPageIDs = [];
  64         private $mRedirectTitles = [];
  65         private $mSpecialTitles = [];
  66         private $mNormalizedTitles = [];
  67         private $mInterwikiTitles = [];
  68         /** @var Title[] */
  69         private $mPendingRedirectIDs = [];
  70         private $mResolvedRedirectTitles = [];
  71         private $mConvertedTitles = [];
  72         private $mGoodRevIDs = [];
  73         private $mLiveRevIDs = [];
  74         private $mDeletedRevIDs = [];
  75         private $mMissingRevIDs = [];
  76         private $mGeneratorData = []; // [ns][dbkey] => data array
  77         private $mFakePageId = -1;
  78         private $mCacheMode = 'public';
  79         private $mRequestedPageFields = [];
  80         /** @var int */
  81         private $mDefaultNamespace = NS_MAIN;
  82         /** @var callable|null */
  83         private $mRedirectMergePolicy;
  84
  85         /**
  86          * Add all items from $values into the result
  87          * @param array $result Output
  88          * @param array $values Values to add
  89          * @param string $flag The name of the boolean flag to mark this element
  90          * @param string $name If given, name of the value
  91          */
  92         private static function addValues( array &$result, $values, $flag = null, $name = null ) {
  93                 foreach ( $values as $val ) {
  94                         if ( $val instanceof Title ) {
  95                                 $v = [];
  96                                 ApiQueryBase::addTitleInfo( $v, $val );
  97                         } elseif ( $name !== null ) {
  98                                 $v = [ $name => $val ];
  99                         } else {
 100                                 $v = $val;
 101                         }
 102                         if ( $flag !== null ) {
 103                                 $v[$flag] = true;
 104                         }
 105                         $result[] = $v;
 106                 }
 107         }
 108
 109         /**
 110          * @param ApiBase $dbSource Module implementing getDB().
 111          *        Allows PageSet to reuse existing db connection from the shared state like ApiQuery.
 112          * @param int $flags Zero or more flags like DISABLE_GENERATORS
 113          * @param int $defaultNamespace The namespace to use if none is specified by a prefix.
 114          * @since 1.21 accepts $flags instead of two boolean values
 115          */
 116         public function __construct( ApiBase $dbSource, $flags = 0, $defaultNamespace = NS_MAIN ) {
 117                 parent::__construct( $dbSource->getMain(), $dbSource->getModuleName() );
 118                 $this->mDbSource = $dbSource;
 119                 $this->mAllowGenerator = ( $flags & ApiPageSet::DISABLE_GENERATORS ) == 0;
 120                 $this->mDefaultNamespace = $defaultNamespace;
 121
 122                 $this->mParams = $this->extractRequestParams();
 123                 $this->mResolveRedirects = $this->mParams['redirects'];
 124                 $this->mConvertTitles = $this->mParams['converttitles'];
 125         }
 126
 127         /**
 128          * In case execute() is not called, call this method to mark all relevant parameters as used
 129          * This prevents unused parameters from being reported as warnings
 130          */
 131         public function executeDryRun() {
 132                 $this->executeInternal( true );
 133         }
 134
 135         /**
 136          * Populate the PageSet from the request parameters.
 137          */
 138         public function execute() {
 139                 $this->executeInternal( false );
 140         }
 141
 142         /**
 143          * Populate the PageSet from the request parameters.
 144          * @param bool $isDryRun If true, instantiates generator, but only to mark
 145          *    relevant parameters as used
 146          */
 147         private function executeInternal( $isDryRun ) {
 148                 $generatorName = $this->mAllowGenerator ? $this->mParams['generator'] : null;
 149                 if ( isset( $generatorName ) ) {
 150                         $dbSource = $this->mDbSource;
 151                         if ( !$dbSource instanceof ApiQuery ) {
 152                                 // If the parent container of this pageset is not ApiQuery, we must create it to run generator
 153                                 $dbSource = $this->getMain()->getModuleManager()->getModule( 'query' );
 154                         }
 155                         $generator = $dbSource->getModuleManager()->getModule( $generatorName, null, true );
 156                         if ( $generator === null ) {
 157                                 $this->dieUsage( 'Unknown generator=' . $generatorName, 'badgenerator' );
 158                         }
 159                         if ( !$generator instanceof ApiQueryGeneratorBase ) {
 160                                 $this->dieUsage( "Module $generatorName cannot be used as a generator", 'badgenerator' );
 161                         }
 162                         // Create a temporary pageset to store generator's output,
 163                         // add any additional fields generator may need, and execute pageset to populate titles/pageids
 164                         $tmpPageSet = new ApiPageSet( $dbSource, ApiPageSet::DISABLE_GENERATORS );
 165                         $generator->setGeneratorMode( $tmpPageSet );
 166                         $this->mCacheMode = $generator->getCacheMode( $generator->extractRequestParams() );
 167
 168                         if ( !$isDryRun ) {
 169                                 $generator->requestExtraData( $tmpPageSet );
 170                         }
 171                         $tmpPageSet->executeInternal( $isDryRun );
 172
 173                         // populate this pageset with the generator output
 174                         if ( !$isDryRun ) {
 175                                 $generator->executeGenerator( $this );
 176                                 Hooks::run( 'APIQueryGeneratorAfterExecute', [ &$generator, &$this ] );
 177                         } else {
 178                                 // Prevent warnings from being reported on these parameters
 179                                 $main = $this->getMain();
 180                                 foreach ( $generator->extractRequestParams() as $paramName => $param ) {
 181                                         $main->markParamsUsed( $generator->encodeParamName( $paramName ) );
 182                                 }
 183                         }
 184
 185                         if ( !$isDryRun ) {
 186                                 $this->resolvePendingRedirects();
 187                         }
 188                 } else {
 189                         // Only one of the titles/pageids/revids is allowed at the same time
 190                         $dataSource = null;
 191                         if ( isset( $this->mParams['titles'] ) ) {
 192                                 $dataSource = 'titles';
 193                         }
 194                         if ( isset( $this->mParams['pageids'] ) ) {
 195                                 if ( isset( $dataSource ) ) {
 196                                         $this->dieUsage( "Cannot use 'pageids' at the same time as '$dataSource'", 'multisource' );
 197                                 }
 198                                 $dataSource = 'pageids';
 199                         }
 200                         if ( isset( $this->mParams['revids'] ) ) {
 201                                 if ( isset( $dataSource ) ) {
 202                                         $this->dieUsage( "Cannot use 'revids' at the same time as '$dataSource'", 'multisource' );
 203                                 }
 204                                 $dataSource = 'revids';
 205                         }
 206
 207                         if ( !$isDryRun ) {
 208                                 // Populate page information with the original user input
 209                                 switch ( $dataSource ) {
 210                                         case 'titles':
 211                                                 $this->initFromTitles( $this->mParams['titles'] );
 212                                                 break;
 213                                         case 'pageids':
 214                                                 $this->initFromPageIds( $this->mParams['pageids'] );
 215                                                 break;
 216                                         case 'revids':
 217                                                 if ( $this->mResolveRedirects ) {
 218                                                         $this->setWarning( 'Redirect resolution cannot be used ' .
 219                                                                 'together with the revids= parameter. Any redirects ' .
 220                                                                 'the revids= point to have not been resolved.' );
 221                                                 }
 222                                                 $this->mResolveRedirects = false;
 223                                                 $this->initFromRevIDs( $this->mParams['revids'] );
 224                                                 break;
 225                                         default:
 226                                                 // Do nothing - some queries do not need any of the data sources.
 227                                                 break;
 228                                 }
 229                         }
 230                 }
 231         }
 232
 233         /**
 234          * Check whether this PageSet is resolving redirects
 235          * @return bool
 236          */
 237         public function isResolvingRedirects() {
 238                 return $this->mResolveRedirects;
 239         }
 240
 241         /**
 242          * Return the parameter name that is the source of data for this PageSet
 243          *
 244          * If multiple source parameters are specified (e.g. titles and pageids),
 245          * one will be named arbitrarily.
 246          *
 247          * @return string|null
 248          */
 249         public function getDataSource() {
 250                 if ( $this->mAllowGenerator && isset( $this->mParams['generator'] ) ) {
 251                         return 'generator';
 252                 }
 253                 if ( isset( $this->mParams['titles'] ) ) {
 254                         return 'titles';
 255                 }
 256                 if ( isset( $this->mParams['pageids'] ) ) {
 257                         return 'pageids';
 258                 }
 259                 if ( isset( $this->mParams['revids'] ) ) {
 260                         return 'revids';
 261                 }
 262
 263                 return null;
 264         }
 265
 266         /**
 267          * Request an additional field from the page table.
 268          * Must be called before execute()
 269          * @param string $fieldName Field name
 270          */
 271         public function requestField( $fieldName ) {
 272                 $this->mRequestedPageFields[$fieldName] = null;
 273         }
 274
 275         /**
 276          * Get the value of a custom field previously requested through
 277          * requestField()
 278          * @param string $fieldName Field name
 279          * @return mixed Field value
 280          */
 281         public function getCustomField( $fieldName ) {
 282                 return $this->mRequestedPageFields[$fieldName];
 283         }
 284
 285         /**
 286          * Get the fields that have to be queried from the page table:
 287          * the ones requested through requestField() and a few basic ones
 288          * we always need
 289          * @return array Array of field names
 290          */
 291         public function getPageTableFields() {
 292                 // Ensure we get minimum required fields
 293                 // DON'T change this order
 294                 $pageFlds = [
 295                         'page_namespace' => null,
 296                         'page_title' => null,
 297                         'page_id' => null,
 298                 ];
 299
 300                 if ( $this->mResolveRedirects ) {
 301                         $pageFlds['page_is_redirect'] = null;
 302                 }
 303
 304                 if ( $this->getConfig()->get( 'ContentHandlerUseDB' ) ) {
 305                         $pageFlds['page_content_model'] = null;
 306                 }
 307
 308                 if ( $this->getConfig()->get( 'PageLanguageUseDB' ) ) {
 309                         $pageFlds['page_lang'] = null;
 310                 }
 311
 312                 // only store non-default fields
 313                 $this->mRequestedPageFields = array_diff_key( $this->mRequestedPageFields, $pageFlds );
 314
 315                 $pageFlds = array_merge( $pageFlds, $this->mRequestedPageFields );
 316
 317                 return array_keys( $pageFlds );
 318         }
 319
 320         /**
 321          * Returns an array [ns][dbkey] => page_id for all requested titles.
 322          * page_id is a unique negative number in case title was not found.
 323          * Invalid titles will also have negative page IDs and will be in namespace 0
 324          * @return array
 325          */
 326         public function getAllTitlesByNamespace() {
 327                 return $this->mAllPages;
 328         }
 329
 330         /**
 331          * All Title objects provided.
 332          * @return Title[]
 333          */
 334         public function getTitles() {
 335                 return $this->mTitles;
 336         }
 337
 338         /**
 339          * Returns the number of unique pages (not revisions) in the set.
 340          * @return int
 341          */
 342         public function getTitleCount() {
 343                 return count( $this->mTitles );
 344         }
 345
 346         /**
 347          * Returns an array [ns][dbkey] => page_id for all good titles.
 348          * @return array
 349          */
 350         public function getGoodTitlesByNamespace() {
 351                 return $this->mGoodPages;
 352         }
 353
 354         /**
 355          * Title objects that were found in the database.
 356          * @return Title[] Array page_id (int) => Title (obj)
 357          */
 358         public function getGoodTitles() {
 359                 return $this->mGoodTitles;
 360         }
 361
 362         /**
 363          * Returns the number of found unique pages (not revisions) in the set.
 364          * @return int
 365          */
 366         public function getGoodTitleCount() {
 367                 return count( $this->mGoodTitles );
 368         }
 369
 370         /**
 371          * Returns an array [ns][dbkey] => fake_page_id for all missing titles.
 372          * fake_page_id is a unique negative number.
 373          * @return array
 374          */
 375         public function getMissingTitlesByNamespace() {
 376                 return $this->mMissingPages;
 377         }
 378
 379         /**
 380          * Title objects that were NOT found in the database.
 381          * The array's index will be negative for each item
 382          * @return Title[]
 383          */
 384         public function getMissingTitles() {
 385                 return $this->mMissingTitles;
 386         }
 387
 388         /**
 389          * Returns an array [ns][dbkey] => page_id for all good and missing titles.
 390          * @return array
 391          */
 392         public function getGoodAndMissingTitlesByNamespace() {
 393                 return $this->mGoodAndMissingPages;
 394         }
 395
 396         /**
 397          * Title objects for good and missing titles.
 398          * @return array
 399          */
 400         public function getGoodAndMissingTitles() {
 401                 return $this->mGoodTitles + $this->mMissingTitles;
 402         }
 403
 404         /**
 405          * Titles that were deemed invalid by Title::newFromText()
 406          * The array's index will be unique and negative for each item
 407          * @deprecated since 1.26, use self::getInvalidTitlesAndReasons()
 408          * @return string[] Array of strings (not Title objects)
 409          */
 410         public function getInvalidTitles() {
 411                 wfDeprecated( __METHOD__, '1.26' );
 412                 return array_map( function ( $t ) {
 413                         return $t['title'];
 414                 }, $this->mInvalidTitles );
 415         }
 416
 417         /**
 418          * Titles that were deemed invalid by Title::newFromText()
 419          * The array's index will be unique and negative for each item
 420          * @return array[] Array of arrays with 'title' and 'invalidreason' properties
 421          */
 422         public function getInvalidTitlesAndReasons() {
 423                 return $this->mInvalidTitles;
 424         }
 425
 426         /**
 427          * Page IDs that were not found in the database
 428          * @return array Array of page IDs
 429          */
 430         public function getMissingPageIDs() {
 431                 return $this->mMissingPageIDs;
 432         }
 433
 434         /**
 435          * Get a list of redirect resolutions - maps a title to its redirect
 436          * target, as an array of output-ready arrays
 437          * @return Title[]
 438          */
 439         public function getRedirectTitles() {
 440                 return $this->mRedirectTitles;
 441         }
 442
 443         /**
 444          * Get a list of redirect resolutions - maps a title to its redirect
 445          * target. Includes generator data for redirect source when available.
 446          * @param ApiResult $result
 447          * @return array Array of prefixed_title (string) => Title object
 448          * @since 1.21
 449          */
 450         public function getRedirectTitlesAsResult( $result = null ) {
 451                 $values = [];
 452                 foreach ( $this->getRedirectTitles() as $titleStrFrom => $titleTo ) {
 453                         $r = [
 454                                 'from' => strval( $titleStrFrom ),
 455                                 'to' => $titleTo->getPrefixedText(),
 456                         ];
 457                         if ( $titleTo->hasFragment() ) {
 458                                 $r['tofragment'] = $titleTo->getFragment();
 459                         }
 460                         if ( $titleTo->isExternal() ) {
 461                                 $r['tointerwiki'] = $titleTo->getInterwiki();
 462                         }
 463                         if ( isset( $this->mResolvedRedirectTitles[$titleStrFrom] ) ) {
 464                                 $titleFrom = $this->mResolvedRedirectTitles[$titleStrFrom];
 465                                 $ns = $titleFrom->getNamespace();
 466                                 $dbkey = $titleFrom->getDBkey();
 467                                 if ( isset( $this->mGeneratorData[$ns][$dbkey] ) ) {
 468                                         $r = array_merge( $this->mGeneratorData[$ns][$dbkey], $r );
 469                                 }
 470                         }
 471
 472                         $values[] = $r;
 473                 }
 474                 if ( !empty( $values ) && $result ) {
 475                         ApiResult::setIndexedTagName( $values, 'r' );
 476                 }
 477
 478                 return $values;
 479         }
 480
 481         /**
 482          * Get a list of title normalizations - maps a title to its normalized
 483          * version.
 484          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 485          */
 486         public function getNormalizedTitles() {
 487                 return $this->mNormalizedTitles;
 488         }
 489
 490         /**
 491          * Get a list of title normalizations - maps a title to its normalized
 492          * version in the form of result array.
 493          * @param ApiResult $result
 494          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 495          * @since 1.21
 496          */
 497         public function getNormalizedTitlesAsResult( $result = null ) {
 498                 $values = [];
 499                 foreach ( $this->getNormalizedTitles() as $rawTitleStr => $titleStr ) {
 500                         $values[] = [
 501                                 'from' => $rawTitleStr,
 502                                 'to' => $titleStr
 503                         ];
 504                 }
 505                 if ( !empty( $values ) && $result ) {
 506                         ApiResult::setIndexedTagName( $values, 'n' );
 507                 }
 508
 509                 return $values;
 510         }
 511
 512         /**
 513          * Get a list of title conversions - maps a title to its converted
 514          * version.
 515          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 516          */
 517         public function getConvertedTitles() {
 518                 return $this->mConvertedTitles;
 519         }
 520
 521         /**
 522          * Get a list of title conversions - maps a title to its converted
 523          * version as a result array.
 524          * @param ApiResult $result
 525          * @return array Array of (from, to) strings
 526          * @since 1.21
 527          */
 528         public function getConvertedTitlesAsResult( $result = null ) {
 529                 $values = [];
 530                 foreach ( $this->getConvertedTitles() as $rawTitleStr => $titleStr ) {
 531                         $values[] = [
 532                                 'from' => $rawTitleStr,
 533                                 'to' => $titleStr
 534                         ];
 535                 }
 536                 if ( !empty( $values ) && $result ) {
 537                         ApiResult::setIndexedTagName( $values, 'c' );
 538                 }
 539
 540                 return $values;
 541         }
 542
 543         /**
 544          * Get a list of interwiki titles - maps a title to its interwiki
 545          * prefix.
 546          * @return array Array of raw_prefixed_title (string) => interwiki_prefix (string)
 547          */
 548         public function getInterwikiTitles() {
 549                 return $this->mInterwikiTitles;
 550         }
 551
 552         /**
 553          * Get a list of interwiki titles - maps a title to its interwiki
 554          * prefix as result.
 555          * @param ApiResult $result
 556          * @param bool $iwUrl
 557          * @return array Array of raw_prefixed_title (string) => interwiki_prefix (string)
 558          * @since 1.21
 559          */
 560         public function getInterwikiTitlesAsResult( $result = null, $iwUrl = false ) {
 561                 $values = [];
 562                 foreach ( $this->getInterwikiTitles() as $rawTitleStr => $interwikiStr ) {
 563                         $item = [
 564                                 'title' => $rawTitleStr,
 565                                 'iw' => $interwikiStr,
 566                         ];
 567                         if ( $iwUrl ) {
 568                                 $title = Title::newFromText( $rawTitleStr );
 569                                 $item['url'] = $title->getFullURL( '', false, PROTO_CURRENT );
 570                         }
 571                         $values[] = $item;
 572                 }
 573                 if ( !empty( $values ) && $result ) {
 574                         ApiResult::setIndexedTagName( $values, 'i' );
 575                 }
 576
 577                 return $values;
 578         }
 579
 580         /**
 581          * Get an array of invalid/special/missing titles.
 582          *
 583          * @param array $invalidChecks List of types of invalid titles to include.
 584          *   Recognized values are:
 585          *   - invalidTitles: Titles and reasons from $this->getInvalidTitlesAndReasons()
 586          *   - special: Titles from $this->getSpecialTitles()
 587          *   - missingIds: ids from $this->getMissingPageIDs()
 588          *   - missingRevIds: ids from $this->getMissingRevisionIDs()
 589          *   - missingTitles: Titles from $this->getMissingTitles()
 590          *   - interwikiTitles: Titles from $this->getInterwikiTitlesAsResult()
 591          * @return array Array suitable for inclusion in the response
 592          * @since 1.23
 593          */
 594         public function getInvalidTitlesAndRevisions( $invalidChecks = [ 'invalidTitles',
 595                 'special', 'missingIds', 'missingRevIds', 'missingTitles', 'interwikiTitles' ]
 596         ) {
 597                 $result = [];
 598                 if ( in_array( 'invalidTitles', $invalidChecks ) ) {
 599                         self::addValues( $result, $this->getInvalidTitlesAndReasons(), 'invalid' );
 600                 }
 601                 if ( in_array( 'special', $invalidChecks ) ) {
 602                         self::addValues( $result, $this->getSpecialTitles(), 'special', 'title' );
 603                 }
 604                 if ( in_array( 'missingIds', $invalidChecks ) ) {
 605                         self::addValues( $result, $this->getMissingPageIDs(), 'missing', 'pageid' );
 606                 }
 607                 if ( in_array( 'missingRevIds', $invalidChecks ) ) {
 608                         self::addValues( $result, $this->getMissingRevisionIDs(), 'missing', 'revid' );
 609                 }
 610                 if ( in_array( 'missingTitles', $invalidChecks ) ) {
 611                         self::addValues( $result, $this->getMissingTitles(), 'missing' );
 612                 }
 613                 if ( in_array( 'interwikiTitles', $invalidChecks ) ) {
 614                         self::addValues( $result, $this->getInterwikiTitlesAsResult() );
 615                 }
 616
 617                 return $result;
 618         }
 619
 620         /**
 621          * Get the list of valid revision IDs (requested with the revids= parameter)
 622          * @return array Array of revID (int) => pageID (int)
 623          */
 624         public function getRevisionIDs() {
 625                 return $this->mGoodRevIDs;
 626         }
 627
 628         /**
 629          * Get the list of non-deleted revision IDs (requested with the revids= parameter)
 630          * @return array Array of revID (int) => pageID (int)
 631          */
 632         public function getLiveRevisionIDs() {
 633                 return $this->mLiveRevIDs;
 634         }
 635
 636         /**
 637          * Get the list of revision IDs that were associated with deleted titles.
 638          * @return array Array of revID (int) => pageID (int)
 639          */
 640         public function getDeletedRevisionIDs() {
 641                 return $this->mDeletedRevIDs;
 642         }
 643
 644         /**
 645          * Revision IDs that were not found in the database
 646          * @return array Array of revision IDs
 647          */
 648         public function getMissingRevisionIDs() {
 649                 return $this->mMissingRevIDs;
 650         }
 651
 652         /**
 653          * Revision IDs that were not found in the database as result array.
 654          * @param ApiResult $result
 655          * @return array Array of revision IDs
 656          * @since 1.21
 657          */
 658         public function getMissingRevisionIDsAsResult( $result = null ) {
 659                 $values = [];
 660                 foreach ( $this->getMissingRevisionIDs() as $revid ) {
 661                         $values[$revid] = [
 662                                 'revid' => $revid
 663                         ];
 664                 }
 665                 if ( !empty( $values ) && $result ) {
 666                         ApiResult::setIndexedTagName( $values, 'rev' );
 667                 }
 668
 669                 return $values;
 670         }
 671
 672         /**
 673          * Get the list of titles with negative namespace
 674          * @return Title[]
 675          */
 676         public function getSpecialTitles() {
 677                 return $this->mSpecialTitles;
 678         }
 679
 680         /**
 681          * Returns the number of revisions (requested with revids= parameter).
 682          * @return int Number of revisions.
 683          */
 684         public function getRevisionCount() {
 685                 return count( $this->getRevisionIDs() );
 686         }
 687
 688         /**
 689          * Populate this PageSet from a list of Titles
 690          * @param array $titles Array of Title objects
 691          */
 692         public function populateFromTitles( $titles ) {
 693                 $this->initFromTitles( $titles );
 694         }
 695
 696         /**
 697          * Populate this PageSet from a list of page IDs
 698          * @param array $pageIDs Array of page IDs
 699          */
 700         public function populateFromPageIDs( $pageIDs ) {
 701                 $this->initFromPageIds( $pageIDs );
 702         }
 703
 704         /**
 705          * Populate this PageSet from a rowset returned from the database
 706          *
 707          * Note that the query result must include the columns returned by
 708          * $this->getPageTableFields().
 709          *
 710          * @param IDatabase $db
 711          * @param ResultWrapper $queryResult Query result object
 712          */
 713         public function populateFromQueryResult( $db, $queryResult ) {
 714                 $this->initFromQueryResult( $queryResult );
 715         }
 716
 717         /**
 718          * Populate this PageSet from a list of revision IDs
 719          * @param array $revIDs Array of revision IDs
 720          */
 721         public function populateFromRevisionIDs( $revIDs ) {
 722                 $this->initFromRevIDs( $revIDs );
 723         }
 724
 725         /**
 726          * Extract all requested fields from the row received from the database
 727          * @param stdClass $row Result row
 728          */
 729         public function processDbRow( $row ) {
 730                 // Store Title object in various data structures
 731                 $title = Title::newFromRow( $row );
 732
 733                 $pageId = intval( $row->page_id );
 734                 $this->mAllPages[$row->page_namespace][$row->page_title] = $pageId;
 735                 $this->mTitles[] = $title;
 736
 737                 if ( $this->mResolveRedirects && $row->page_is_redirect == '1' ) {
 738                         $this->mPendingRedirectIDs[$pageId] = $title;
 739                 } else {
 740                         $this->mGoodPages[$row->page_namespace][$row->page_title] = $pageId;
 741                         $this->mGoodAndMissingPages[$row->page_namespace][$row->page_title] = $pageId;
 742                         $this->mGoodTitles[$pageId] = $title;
 743                 }
 744
 745                 foreach ( $this->mRequestedPageFields as $fieldName => &$fieldValues ) {
 746                         $fieldValues[$pageId] = $row->$fieldName;
 747                 }
 748         }
 749
 750         /**
 751          * This method populates internal variables with page information
 752          * based on the given array of title strings.
 753          *
 754          * Steps:
 755          * #1 For each title, get data from `page` table
 756          * #2 If page was not found in the DB, store it as missing
 757          *
 758          * Additionally, when resolving redirects:
 759          * #3 If no more redirects left, stop.
 760          * #4 For each redirect, get its target from the `redirect` table.
 761          * #5 Substitute the original LinkBatch object with the new list
 762          * #6 Repeat from step #1
 763          *
 764          * @param array $titles Array of Title objects or strings
 765          */
 766         private function initFromTitles( $titles ) {
 767                 // Get validated and normalized title objects
 768                 $linkBatch = $this->processTitlesArray( $titles );
 769                 if ( $linkBatch->isEmpty() ) {
 770                         return;
 771                 }
 772
 773                 $db = $this->getDB();
 774                 $set = $linkBatch->constructSet( 'page', $db );
 775
 776                 // Get pageIDs data from the `page` table
 777                 $res = $db->select( 'page', $this->getPageTableFields(), $set,
 778                         __METHOD__ );
 779
 780                 // Hack: get the ns:titles stored in [ ns => [ titles ] ] format
 781                 $this->initFromQueryResult( $res, $linkBatch->data, true ); // process Titles
 782
 783                 // Resolve any found redirects
 784                 $this->resolvePendingRedirects();
 785         }
 786
 787         /**
 788          * Does the same as initFromTitles(), but is based on page IDs instead
 789          * @param array $pageids Array of page IDs
 790          */
 791         private function initFromPageIds( $pageids ) {
 792                 if ( !$pageids ) {
 793                         return;
 794                 }
 795
 796                 $pageids = array_map( 'intval', $pageids ); // paranoia
 797                 $remaining = array_flip( $pageids );
 798
 799                 $pageids = self::getPositiveIntegers( $pageids );
 800
 801                 $res = null;
 802                 if ( !empty( $pageids ) ) {
 803                         $set = [
 804                                 'page_id' => $pageids
 805                         ];
 806                         $db = $this->getDB();
 807
 808                         // Get pageIDs data from the `page` table
 809                         $res = $db->select( 'page', $this->getPageTableFields(), $set,
 810                                 __METHOD__ );
 811                 }
 812
 813                 $this->initFromQueryResult( $res, $remaining, false ); // process PageIDs
 814
 815                 // Resolve any found redirects
 816                 $this->resolvePendingRedirects();
 817         }
 818
 819         /**
 820          * Iterate through the result of the query on 'page' table,
 821          * and for each row create and store title object and save any extra fields requested.
 822          * @param ResultWrapper $res DB Query result
 823          * @param array $remaining Array of either pageID or ns/title elements (optional).
 824          *        If given, any missing items will go to $mMissingPageIDs and $mMissingTitles
 825          * @param bool $processTitles Must be provided together with $remaining.
 826          *        If true, treat $remaining as an array of [ns][title]
 827          *        If false, treat it as an array of [pageIDs]
 828          */
 829         private function initFromQueryResult( $res, &$remaining = null, $processTitles = null ) {
 830                 if ( !is_null( $remaining ) && is_null( $processTitles ) ) {
 831                         ApiBase::dieDebug( __METHOD__, 'Missing $processTitles parameter when $remaining is provided' );
 832                 }
 833
 834                 $usernames = [];
 835                 if ( $res ) {
 836                         foreach ( $res as $row ) {
 837                                 $pageId = intval( $row->page_id );
 838
 839                                 // Remove found page from the list of remaining items
 840                                 if ( isset( $remaining ) ) {
 841                                         if ( $processTitles ) {
 842                                                 unset( $remaining[$row->page_namespace][$row->page_title] );
 843                                         } else {
 844                                                 unset( $remaining[$pageId] );
 845                                         }
 846                                 }
 847
 848                                 // Store any extra fields requested by modules
 849                                 $this->processDbRow( $row );
 850
 851                                 // Need gender information
 852                                 if ( MWNamespace::hasGenderDistinction( $row->page_namespace ) ) {
 853                                         $usernames[] = $row->page_title;
 854                                 }
 855                         }
 856                 }
 857
 858                 if ( isset( $remaining ) ) {
 859                         // Any items left in the $remaining list are added as missing
 860                         if ( $processTitles ) {
 861                                 // The remaining titles in $remaining are non-existent pages
 862                                 foreach ( $remaining as $ns => $dbkeys ) {
 863                                         foreach ( array_keys( $dbkeys ) as $dbkey ) {
 864                                                 $title = Title::makeTitle( $ns, $dbkey );
 865                                                 $this->mAllPages[$ns][$dbkey] = $this->mFakePageId;
 866                                                 $this->mMissingPages[$ns][$dbkey] = $this->mFakePageId;
 867                                                 $this->mGoodAndMissingPages[$ns][$dbkey] = $this->mFakePageId;
 868                                                 $this->mMissingTitles[$this->mFakePageId] = $title;
 869                                                 $this->mFakePageId--;
 870                                                 $this->mTitles[] = $title;
 871
 872                                                 // need gender information
 873                                                 if ( MWNamespace::hasGenderDistinction( $ns ) ) {
 874                                                         $usernames[] = $dbkey;
 875                                                 }
 876                                         }
 877                                 }
 878                         } else {
 879                                 // The remaining pageids do not exist
 880                                 if ( !$this->mMissingPageIDs ) {
 881                                         $this->mMissingPageIDs = array_keys( $remaining );
 882                                 } else {
 883                                         $this->mMissingPageIDs = array_merge( $this->mMissingPageIDs, array_keys( $remaining ) );
 884                                 }
 885                         }
 886                 }
 887
 888                 // Get gender information
 889                 $genderCache = GenderCache::singleton();
 890                 $genderCache->doQuery( $usernames, __METHOD__ );
 891         }
 892
 893         /**
 894          * Does the same as initFromTitles(), but is based on revision IDs
 895          * instead
 896          * @param array $revids Array of revision IDs
 897          */
 898         private function initFromRevIDs( $revids ) {
 899                 if ( !$revids ) {
 900                         return;
 901                 }
 902
 903                 $revids = array_map( 'intval', $revids ); // paranoia
 904                 $db = $this->getDB();
 905                 $pageids = [];
 906                 $remaining = array_flip( $revids );
 907
 908                 $revids = self::getPositiveIntegers( $revids );
 909
 910                 if ( !empty( $revids ) ) {
 911                         $tables = [ 'revision', 'page' ];
 912                         $fields = [ 'rev_id', 'rev_page' ];
 913                         $where = [ 'rev_id' => $revids, 'rev_page = page_id' ];
 914
 915                         // Get pageIDs data from the `page` table
 916                         $res = $db->select( $tables, $fields, $where, __METHOD__ );
 917                         foreach ( $res as $row ) {
 918                                 $revid = intval( $row->rev_id );
 919                                 $pageid = intval( $row->rev_page );
 920                                 $this->mGoodRevIDs[$revid] = $pageid;
 921                                 $this->mLiveRevIDs[$revid] = $pageid;
 922                                 $pageids[$pageid] = '';
 923                                 unset( $remaining[$revid] );
 924                         }
 925                 }
 926
 927                 $this->mMissingRevIDs = array_keys( $remaining );
 928
 929                 // Populate all the page information
 930                 $this->initFromPageIds( array_keys( $pageids ) );
 931
 932                 // If the user can see deleted revisions, pull out the corresponding
 933                 // titles from the archive table and include them too. We ignore
 934                 // ar_page_id because deleted revisions are tied by title, not page_id.
 935                 if ( !empty( $this->mMissingRevIDs ) && $this->getUser()->isAllowed( 'deletedhistory' ) ) {
 936                         $remaining = array_flip( $this->mMissingRevIDs );
 937                         $tables = [ 'archive' ];
 938                         $fields = [ 'ar_rev_id', 'ar_namespace', 'ar_title' ];
 939                         $where = [ 'ar_rev_id' => $this->mMissingRevIDs ];
 940
 941                         $res = $db->select( $tables, $fields, $where, __METHOD__ );
 942                         $titles = [];
 943                         foreach ( $res as $row ) {
 944                                 $revid = intval( $row->ar_rev_id );
 945                                 $titles[$revid] = Title::makeTitle( $row->ar_namespace, $row->ar_title );
 946                                 unset( $remaining[$revid] );
 947                         }
 948
 949                         $this->initFromTitles( $titles );
 950
 951                         foreach ( $titles as $revid => $title ) {
 952                                 $ns = $title->getNamespace();
 953                                 $dbkey = $title->getDBkey();
 954
 955                                 // Handle converted titles
 956                                 if ( !isset( $this->mAllPages[$ns][$dbkey] ) &&
 957                                         isset( $this->mConvertedTitles[$title->getPrefixedText()] )
 958                                 ) {
 959                                         $title = Title::newFromText( $this->mConvertedTitles[$title->getPrefixedText()] );
 960                                         $ns = $title->getNamespace();
 961                                         $dbkey = $title->getDBkey();
 962                                 }
 963
 964                                 if ( isset( $this->mAllPages[$ns][$dbkey] ) ) {
 965                                         $this->mGoodRevIDs[$revid] = $this->mAllPages[$ns][$dbkey];
 966                                         $this->mDeletedRevIDs[$revid] = $this->mAllPages[$ns][$dbkey];
 967                                 } else {
 968                                         $remaining[$revid] = true;
 969                                 }
 970                         }
 971
 972                         $this->mMissingRevIDs = array_keys( $remaining );
 973                 }
 974         }
 975
 976         /**
 977          * Resolve any redirects in the result if redirect resolution was
 978          * requested. This function is called repeatedly until all redirects
 979          * have been resolved.
 980          */
 981         private function resolvePendingRedirects() {
 982                 if ( $this->mResolveRedirects ) {
 983                         $db = $this->getDB();
 984                         $pageFlds = $this->getPageTableFields();
 985
 986                         // Repeat until all redirects have been resolved
 987                         // The infinite loop is prevented by keeping all known pages in $this->mAllPages
 988                         while ( $this->mPendingRedirectIDs ) {
 989                                 // Resolve redirects by querying the pagelinks table, and repeat the process
 990                                 // Create a new linkBatch object for the next pass
 991                                 $linkBatch = $this->getRedirectTargets();
 992
 993                                 if ( $linkBatch->isEmpty() ) {
 994                                         break;
 995                                 }
 996
 997                                 $set = $linkBatch->constructSet( 'page', $db );
 998                                 if ( $set === false ) {
 999                                         break;
1000                                 }
1001
1002                                 // Get pageIDs data from the `page` table
1003                                 $res = $db->select( 'page', $pageFlds, $set, __METHOD__ );
1004
1005                                 // Hack: get the ns:titles stored in array(ns => array(titles)) format
1006                                 $this->initFromQueryResult( $res, $linkBatch->data, true );
1007                         }
1008                 }
1009         }
1010
1011         /**
1012          * Get the targets of the pending redirects from the database
1013          *
1014          * Also creates entries in the redirect table for redirects that don't
1015          * have one.
1016          * @return LinkBatch
1017          */
1018         private function getRedirectTargets() {
1019                 $lb = new LinkBatch();
1020                 $db = $this->getDB();
1021
1022                 $res = $db->select(
1023                         'redirect',
1024                         [
1025                                 'rd_from',
1026                                 'rd_namespace',
1027                                 'rd_fragment',
1028                                 'rd_interwiki',
1029                                 'rd_title'
1030                         ], [ 'rd_from' => array_keys( $this->mPendingRedirectIDs ) ],
1031                         __METHOD__
1032                 );
1033                 foreach ( $res as $row ) {
1034                         $rdfrom = intval( $row->rd_from );
1035                         $from = $this->mPendingRedirectIDs[$rdfrom]->getPrefixedText();
1036                         $to = Title::makeTitle(
1037                                 $row->rd_namespace,
1038                                 $row->rd_title,
1039                                 $row->rd_fragment,
1040                                 $row->rd_interwiki
1041                         );
1042                         $this->mResolvedRedirectTitles[$from] = $this->mPendingRedirectIDs[$rdfrom];
1043                         unset( $this->mPendingRedirectIDs[$rdfrom] );
1044                         if ( $to->isExternal() ) {
1045                                 $this->mInterwikiTitles[$to->getPrefixedText()] = $to->getInterwiki();
1046                         } elseif ( !isset( $this->mAllPages[$row->rd_namespace][$row->rd_title] ) ) {
1047                                 $lb->add( $row->rd_namespace, $row->rd_title );
1048                         }
1049                         $this->mRedirectTitles[$from] = $to;
1050                 }
1051
1052                 if ( $this->mPendingRedirectIDs ) {
1053                         // We found pages that aren't in the redirect table
1054                         // Add them
1055                         foreach ( $this->mPendingRedirectIDs as $id => $title ) {
1056                                 $page = WikiPage::factory( $title );
1057                                 $rt = $page->insertRedirect();
1058                                 if ( !$rt ) {
1059                                         // What the hell. Let's just ignore this
1060                                         continue;
1061                                 }
1062                                 $lb->addObj( $rt );
1063                                 $from = $title->getPrefixedText();
1064                                 $this->mResolvedRedirectTitles[$from] = $title;
1065                                 $this->mRedirectTitles[$from] = $rt;
1066                                 unset( $this->mPendingRedirectIDs[$id] );
1067                         }
1068                 }
1069
1070                 return $lb;
1071         }
1072
1073         /**
1074          * Get the cache mode for the data generated by this module.
1075          * All PageSet users should take into account whether this returns a more-restrictive
1076          * cache mode than the using module itself. For possible return values and other
1077          * details about cache modes, see ApiMain::setCacheMode()
1078          *
1079          * Public caching will only be allowed if *all* the modules that supply
1080          * data for a given request return a cache mode of public.
1081          *
1082          * @param array|null $params
1083          * @return string
1084          * @since 1.21
1085          */
1086         public function getCacheMode( $params = null ) {
1087                 return $this->mCacheMode;
1088         }
1089
1090         /**
1091          * Given an array of title strings, convert them into Title objects.
1092          * Alternatively, an array of Title objects may be given.
1093          * This method validates access rights for the title,
1094          * and appends normalization values to the output.
1095          *
1096          * @param array $titles Array of Title objects or strings
1097          * @return LinkBatch
1098          */
1099         private function processTitlesArray( $titles ) {
1100                 $usernames = [];
1101                 $linkBatch = new LinkBatch();
1102
1103                 foreach ( $titles as $title ) {
1104                         if ( is_string( $title ) ) {
1105                                 try {
1106                                         $titleObj = Title::newFromTextThrow( $title, $this->mDefaultNamespace );
1107                                 } catch ( MalformedTitleException $ex ) {
1108                                         // Handle invalid titles gracefully
1109                                         $this->mAllPages[0][$title] = $this->mFakePageId;
1110                                         $this->mInvalidTitles[$this->mFakePageId] = [
1111                                                 'title' => $title,
1112                                                 'invalidreason' => $ex->getMessage(),
1113                                         ];
1114                                         $this->mFakePageId--;
1115                                         continue; // There's nothing else we can do
1116                                 }
1117                         } else {
1118                                 $titleObj = $title;
1119                         }
1120                         $unconvertedTitle = $titleObj->getPrefixedText();
1121                         $titleWasConverted = false;
1122                         if ( $titleObj->isExternal() ) {
1123                                 // This title is an interwiki link.
1124                                 $this->mInterwikiTitles[$unconvertedTitle] = $titleObj->getInterwiki();
1125                         } else {
1126                                 // Variants checking
1127                                 global $wgContLang;
1128                                 if ( $this->mConvertTitles &&
1129                                         count( $wgContLang->getVariants() ) > 1 &&
1130                                         !$titleObj->exists()
1131                                 ) {
1132                                         // Language::findVariantLink will modify titleText and titleObj into
1133                                         // the canonical variant if possible
1134                                         $titleText = is_string( $title ) ? $title : $titleObj->getPrefixedText();
1135                                         $wgContLang->findVariantLink( $titleText, $titleObj );
1136                                         $titleWasConverted = $unconvertedTitle !== $titleObj->getPrefixedText();
1137                                 }
1138
1139                                 if ( $titleObj->getNamespace() < 0 ) {
1140                                         // Handle Special and Media pages
1141                                         $titleObj = $titleObj->fixSpecialName();
1142                                         $this->mSpecialTitles[$this->mFakePageId] = $titleObj;
1143                                         $this->mFakePageId--;
1144                                 } else {
1145                                         // Regular page
1146                                         $linkBatch->addObj( $titleObj );
1147                                 }
1148                         }
1149
1150                         // Make sure we remember the original title that was
1151                         // given to us. This way the caller can correlate new
1152                         // titles with the originally requested when e.g. the
1153                         // namespace is localized or the capitalization is
1154                         // different
1155                         if ( $titleWasConverted ) {
1156                                 $this->mConvertedTitles[$unconvertedTitle] = $titleObj->getPrefixedText();
1157                                 // In this case the page can't be Special.
1158                                 if ( is_string( $title ) && $title !== $unconvertedTitle ) {
1159                                         $this->mNormalizedTitles[$title] = $unconvertedTitle;
1160                                 }
1161                         } elseif ( is_string( $title ) && $title !== $titleObj->getPrefixedText() ) {
1162                                 $this->mNormalizedTitles[$title] = $titleObj->getPrefixedText();
1163                         }
1164
1165                         // Need gender information
1166                         if ( MWNamespace::hasGenderDistinction( $titleObj->getNamespace() ) ) {
1167                                 $usernames[] = $titleObj->getText();
1168                         }
1169                 }
1170                 // Get gender information
1171                 $genderCache = GenderCache::singleton();
1172                 $genderCache->doQuery( $usernames, __METHOD__ );
1173
1174                 return $linkBatch;
1175         }
1176
1177         /**
1178          * Set data for a title.
1179          *
1180          * This data may be extracted into an ApiResult using
1181          * self::populateGeneratorData. This should generally be limited to
1182          * data that is likely to be particularly useful to end users rather than
1183          * just being a dump of everything returned in non-generator mode.
1184          *
1185          * Redirects here will *not* be followed, even if 'redirects' was
1186          * specified, since in the case of multiple redirects we can't know which
1187          * source's data to use on the target.
1188          *
1189          * @param Title $title
1190          * @param array $data
1191          */
1192         public function setGeneratorData( Title $title, array $data ) {
1193                 $ns = $title->getNamespace();
1194                 $dbkey = $title->getDBkey();
1195                 $this->mGeneratorData[$ns][$dbkey] = $data;
1196         }
1197
1198         /**
1199          * Controls how generator data about a redirect source is merged into
1200          * the generator data for the redirect target. When not set no data
1201          * is merged. Note that if multiple titles redirect to the same target
1202          * the order of operations is undefined.
1203          *
1204          * Example to include generated data from redirect in target, prefering
1205          * the data generated for the destination when there is a collision:
1206          * @code
1207          *   $pageSet->setRedirectMergePolicy( function( array $current, array $new ) {
1208          *       return $current + $new;
1209          *   } );
1210          * @endcode
1211          *
1212          * @param callable|null $callable Recieves two array arguments, first the
1213          *  generator data for the redirect target and second the generator data
1214          *  for the redirect source. Returns the resulting generator data to use
1215          *  for the redirect target.
1216          */
1217         public function setRedirectMergePolicy( $callable ) {
1218                 $this->mRedirectMergePolicy = $callable;
1219         }
1220
1221         /**
1222          * Populate the generator data for all titles in the result
1223          *
1224          * The page data may be inserted into an ApiResult object or into an
1225          * associative array. The $path parameter specifies the path within the
1226          * ApiResult or array to find the "pages" node.
1227          *
1228          * The "pages" node itself must be an associative array mapping the page ID
1229          * or fake page ID values returned by this pageset (see
1230          * self::getAllTitlesByNamespace() and self::getSpecialTitles()) to
1231          * associative arrays of page data. Each of those subarrays will have the
1232          * data from self::setGeneratorData() merged in.
1233          *
1234          * Data that was set by self::setGeneratorData() for pages not in the
1235          * "pages" node will be ignored.
1236          *
1237          * @param ApiResult|array &$result
1238          * @param array $path
1239          * @return bool Whether the data fit
1240          */
1241         public function populateGeneratorData( &$result, array $path = [] ) {
1242                 if ( $result instanceof ApiResult ) {
1243                         $data = $result->getResultData( $path );
1244                         if ( $data === null ) {
1245                                 return true;
1246                         }
1247                 } else {
1248                         $data = &$result;
1249                         foreach ( $path as $key ) {
1250                                 if ( !isset( $data[$key] ) ) {
1251                                         // Path isn't in $result, so nothing to add, so everything
1252                                         // "fits"
1253                                         return true;
1254                                 }
1255                                 $data = &$data[$key];
1256                         }
1257                 }
1258                 foreach ( $this->mGeneratorData as $ns => $dbkeys ) {
1259                         if ( $ns === -1 ) {
1260                                 $pages = [];
1261                                 foreach ( $this->mSpecialTitles as $id => $title ) {
1262                                         $pages[$title->getDBkey()] = $id;
1263                                 }
1264                         } else {
1265                                 if ( !isset( $this->mAllPages[$ns] ) ) {
1266                                         // No known titles in the whole namespace. Skip it.
1267                                         continue;
1268                                 }
1269                                 $pages = $this->mAllPages[$ns];
1270                         }
1271                         foreach ( $dbkeys as $dbkey => $genData ) {
1272                                 if ( !isset( $pages[$dbkey] ) ) {
1273                                         // Unknown title. Forget it.
1274                                         continue;
1275                                 }
1276                                 $pageId = $pages[$dbkey];
1277                                 if ( !isset( $data[$pageId] ) ) {
1278                                         // $pageId didn't make it into the result. Ignore it.
1279                                         continue;
1280                                 }
1281
1282                                 if ( $result instanceof ApiResult ) {
1283                                         $path2 = array_merge( $path, [ $pageId ] );
1284                                         foreach ( $genData as $key => $value ) {
1285                                                 if ( !$result->addValue( $path2, $key, $value ) ) {
1286                                                         return false;
1287                                                 }
1288                                         }
1289                                 } else {
1290                                         $data[$pageId] = array_merge( $data[$pageId], $genData );
1291                                 }
1292                         }
1293                 }
1294
1295                 // Merge data generated about redirect titles into the redirect destination
1296                 if ( $this->mRedirectMergePolicy ) {
1297                         foreach ( $this->mResolvedRedirectTitles as $titleFrom ) {
1298                                 $dest = $titleFrom;
1299                                 while ( isset( $this->mRedirectTitles[$dest->getPrefixedText()] ) ) {
1300                                         $dest = $this->mRedirectTitles[$dest->getPrefixedText()];
1301                                 }
1302                                 $fromNs = $titleFrom->getNamespace();
1303                                 $fromDBkey = $titleFrom->getDBkey();
1304                                 $toPageId = $dest->getArticleID();
1305                                 if ( isset( $data[$toPageId] ) &&
1306                                         isset( $this->mGeneratorData[$fromNs][$fromDBkey] )
1307                                 ) {
1308                                         // It is necesary to set both $data and add to $result, if an ApiResult,
1309                                         // to ensure multiple redirects to the same destination are all merged.
1310                                         $data[$toPageId] = call_user_func(
1311                                                 $this->mRedirectMergePolicy,
1312                                                 $data[$toPageId],
1313                                                 $this->mGeneratorData[$fromNs][$fromDBkey]
1314                                         );
1315                                         if ( $result instanceof ApiResult ) {
1316                                                 if ( !$result->addValue( $path, $toPageId, $data[$toPageId], ApiResult::OVERRIDE ) ) {
1317                                                         return false;
1318                                                 }
1319                                         }
1320                                 }
1321                         }
1322                 }
1323
1324                 return true;
1325         }
1326
1327         /**
1328          * Get the database connection (read-only)
1329          * @return DatabaseBase
1330          */
1331         protected function getDB() {
1332                 return $this->mDbSource->getDB();
1333         }
1334
1335         /**
1336          * Returns the input array of integers with all values < 0 removed
1337          *
1338          * @param array $array
1339          * @return array
1340          */
1341         private static function getPositiveIntegers( $array ) {
1342                 // bug 25734 API: possible issue with revids validation
1343                 // It seems with a load of revision rows, MySQL gets upset
1344                 // Remove any < 0 integers, as they can't be valid
1345                 foreach ( $array as $i => $int ) {
1346                         if ( $int < 0 ) {
1347                                 unset( $array[$i] );
1348                         }
1349                 }
1350
1351                 return $array;
1352         }
1353
1354         public function getAllowedParams( $flags = 0 ) {
1355                 $result = [
1356                         'titles' => [
1357                                 ApiBase::PARAM_ISMULTI => true,
1358                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-titles',
1359                         ],
1360                         'pageids' => [
1361                                 ApiBase::PARAM_TYPE => 'integer',
1362                                 ApiBase::PARAM_ISMULTI => true,
1363                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-pageids',
1364                         ],
1365                         'revids' => [
1366                                 ApiBase::PARAM_TYPE => 'integer',
1367                                 ApiBase::PARAM_ISMULTI => true,
1368                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-revids',
1369                         ],
1370                         'generator' => [
1371                                 ApiBase::PARAM_TYPE => null,
1372                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-generator',
1373                                 ApiBase::PARAM_SUBMODULE_PARAM_PREFIX => 'g',
1374                         ],
1375                         'redirects' => [
1376                                 ApiBase::PARAM_DFLT => false,
1377                                 ApiBase::PARAM_HELP_MSG => $this->mAllowGenerator
1378                                         ? 'api-pageset-param-redirects-generator'
1379                                         : 'api-pageset-param-redirects-nogenerator',
1380                         ],
1381                         'converttitles' => [
1382                                 ApiBase::PARAM_DFLT => false,
1383                                 ApiBase::PARAM_HELP_MSG => [
1384                                         'api-pageset-param-converttitles',
1385                                         new DeferredStringifier(
1386                                                 function ( IContextSource $context ) {
1387                                                         return $context->getLanguage()
1388                                                                 ->commaList( LanguageConverter::$languagesWithVariants );
1389                                                 },
1390                                                 $this
1391                                         )
1392                                 ],
1393                         ],
1394                 ];
1395
1396                 if ( !$this->mAllowGenerator ) {
1397                         unset( $result['generator'] );
1398                 } elseif ( $flags & ApiBase::GET_VALUES_FOR_HELP ) {
1399                         $result['generator'][ApiBase::PARAM_TYPE] = 'submodule';
1400                         $result['generator'][ApiBase::PARAM_SUBMODULE_MAP] = $this->getGenerators();
1401                 }
1402
1403                 return $result;
1404         }
1405
1406         private static $generators = null;
1407
1408         /**
1409          * Get an array of all available generators
1410          * @return array
1411          */
1412         private function getGenerators() {
1413                 if ( self::$generators === null ) {
1414                         $query = $this->mDbSource;
1415                         if ( !( $query instanceof ApiQuery ) ) {
1416                                 // If the parent container of this pageset is not ApiQuery,
1417                                 // we must create it to get module manager
1418                                 $query = $this->getMain()->getModuleManager()->getModule( 'query' );
1419                         }
1420                         $gens = [];
1421                         $prefix = $query->getModulePath() . '+';
1422                         $mgr = $query->getModuleManager();
1423                         foreach ( $mgr->getNamesWithClasses() as $name => $class ) {
1424                                 if ( is_subclass_of( $class, 'ApiQueryGeneratorBase' ) ) {
1425                                         $gens[$name] = $prefix . $name;
1426                                 }
1427                         }
1428                         ksort( $gens );
1429                         self::$generators = $gens;
1430                 }
1431
1432                 return self::$generators;
1433         }
1434 }