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 use MediaWiki\MediaWikiServices;
  27 use Wikimedia\Rdbms\ResultWrapper;
  28 use Wikimedia\Rdbms\IDatabase;
  29
  30 /**
  31  * This class contains a list of pages that the client has requested.
  32  * Initially, when the client passes in titles=, pageids=, or revisions=
  33  * parameter, an instance of the ApiPageSet class will normalize titles,
  34  * determine if the pages/revisions exist, and prefetch any additional page
  35  * data requested.
  36  *
  37  * When a generator is used, the result of the generator will become the input
  38  * for the second instance of this class, and all subsequent actions will use
  39  * the second instance for all their work.
  40  *
  41  * @ingroup API
  42  * @since 1.21 derives from ApiBase instead of ApiQueryBase
  43  */
  44 class ApiPageSet extends ApiBase {
  45         /**
  46          * Constructor flag: The new instance of ApiPageSet will ignore the 'generator=' parameter
  47          * @since 1.21
  48          */
  49         const DISABLE_GENERATORS = 1;
  50
  51         private $mDbSource;
  52         private $mParams;
  53         private $mResolveRedirects;
  54         private $mConvertTitles;
  55         private $mAllowGenerator;
  56
  57         private $mAllPages = []; // [ns][dbkey] => page_id or negative when missing
  58         private $mTitles = [];
  59         private $mGoodAndMissingPages = []; // [ns][dbkey] => page_id or negative when missing
  60         private $mGoodPages = []; // [ns][dbkey] => page_id
  61         private $mGoodTitles = [];
  62         private $mMissingPages = []; // [ns][dbkey] => fake page_id
  63         private $mMissingTitles = [];
  64         /** @var array [fake_page_id] => [ 'title' => $title, 'invalidreason' => $reason ] */
  65         private $mInvalidTitles = [];
  66         private $mMissingPageIDs = [];
  67         private $mRedirectTitles = [];
  68         private $mSpecialTitles = [];
  69         private $mAllSpecials = []; // separate from mAllPages to avoid breaking getAllTitlesByNamespace()
  70         private $mNormalizedTitles = [];
  71         private $mInterwikiTitles = [];
  72         /** @var Title[] */
  73         private $mPendingRedirectIDs = [];
  74         private $mResolvedRedirectTitles = [];
  75         private $mConvertedTitles = [];
  76         private $mGoodRevIDs = [];
  77         private $mLiveRevIDs = [];
  78         private $mDeletedRevIDs = [];
  79         private $mMissingRevIDs = [];
  80         private $mGeneratorData = []; // [ns][dbkey] => data array
  81         private $mFakePageId = -1;
  82         private $mCacheMode = 'public';
  83         private $mRequestedPageFields = [];
  84         /** @var int */
  85         private $mDefaultNamespace = NS_MAIN;
  86         /** @var callable|null */
  87         private $mRedirectMergePolicy;
  88
  89         /**
  90          * Add all items from $values into the result
  91          * @param array $result Output
  92          * @param array $values Values to add
  93          * @param string[] $flags The names of boolean flags to mark this element
  94          * @param string $name If given, name of the value
  95          */
  96         private static function addValues( array &$result, $values, $flags = [], $name = null ) {
  97                 foreach ( $values as $val ) {
  98                         if ( $val instanceof Title ) {
  99                                 $v = [];
 100                                 ApiQueryBase::addTitleInfo( $v, $val );
 101                         } elseif ( $name !== null ) {
 102                                 $v = [ $name => $val ];
 103                         } else {
 104                                 $v = $val;
 105                         }
 106                         foreach ( $flags as $flag ) {
 107                                 $v[$flag] = true;
 108                         }
 109                         $result[] = $v;
 110                 }
 111         }
 112
 113         /**
 114          * @param ApiBase $dbSource Module implementing getDB().
 115          *        Allows PageSet to reuse existing db connection from the shared state like ApiQuery.
 116          * @param int $flags Zero or more flags like DISABLE_GENERATORS
 117          * @param int $defaultNamespace The namespace to use if none is specified by a prefix.
 118          * @since 1.21 accepts $flags instead of two boolean values
 119          */
 120         public function __construct( ApiBase $dbSource, $flags = 0, $defaultNamespace = NS_MAIN ) {
 121                 parent::__construct( $dbSource->getMain(), $dbSource->getModuleName() );
 122                 $this->mDbSource = $dbSource;
 123                 $this->mAllowGenerator = ( $flags & ApiPageSet::DISABLE_GENERATORS ) == 0;
 124                 $this->mDefaultNamespace = $defaultNamespace;
 125
 126                 $this->mParams = $this->extractRequestParams();
 127                 $this->mResolveRedirects = $this->mParams['redirects'];
 128                 $this->mConvertTitles = $this->mParams['converttitles'];
 129         }
 130
 131         /**
 132          * In case execute() is not called, call this method to mark all relevant parameters as used
 133          * This prevents unused parameters from being reported as warnings
 134          */
 135         public function executeDryRun() {
 136                 $this->executeInternal( true );
 137         }
 138
 139         /**
 140          * Populate the PageSet from the request parameters.
 141          */
 142         public function execute() {
 143                 $this->executeInternal( false );
 144         }
 145
 146         /**
 147          * Populate the PageSet from the request parameters.
 148          * @param bool $isDryRun If true, instantiates generator, but only to mark
 149          *    relevant parameters as used
 150          */
 151         private function executeInternal( $isDryRun ) {
 152                 $generatorName = $this->mAllowGenerator ? $this->mParams['generator'] : null;
 153                 if ( isset( $generatorName ) ) {
 154                         $dbSource = $this->mDbSource;
 155                         if ( !$dbSource instanceof ApiQuery ) {
 156                                 // If the parent container of this pageset is not ApiQuery, we must create it to run generator
 157                                 $dbSource = $this->getMain()->getModuleManager()->getModule( 'query' );
 158                         }
 159                         $generator = $dbSource->getModuleManager()->getModule( $generatorName, null, true );
 160                         if ( $generator === null ) {
 161                                 $this->dieWithError( [ 'apierror-badgenerator-unknown', $generatorName ], 'badgenerator' );
 162                         }
 163                         if ( !$generator instanceof ApiQueryGeneratorBase ) {
 164                                 $this->dieWithError( [ 'apierror-badgenerator-notgenerator', $generatorName ], 'badgenerator' );
 165                         }
 166                         // Create a temporary pageset to store generator's output,
 167                         // add any additional fields generator may need, and execute pageset to populate titles/pageids
 168                         $tmpPageSet = new ApiPageSet( $dbSource, ApiPageSet::DISABLE_GENERATORS );
 169                         $generator->setGeneratorMode( $tmpPageSet );
 170                         $this->mCacheMode = $generator->getCacheMode( $generator->extractRequestParams() );
 171
 172                         if ( !$isDryRun ) {
 173                                 $generator->requestExtraData( $tmpPageSet );
 174                         }
 175                         $tmpPageSet->executeInternal( $isDryRun );
 176
 177                         // populate this pageset with the generator output
 178                         if ( !$isDryRun ) {
 179                                 $generator->executeGenerator( $this );
 180
 181                                 // Avoid PHP 7.1 warning of passing $this by reference
 182                                 $apiModule = $this;
 183                                 Hooks::run( 'APIQueryGeneratorAfterExecute', [ &$generator, &$apiModule ] );
 184                         } else {
 185                                 // Prevent warnings from being reported on these parameters
 186                                 $main = $this->getMain();
 187                                 foreach ( $generator->extractRequestParams() as $paramName => $param ) {
 188                                         $main->markParamsUsed( $generator->encodeParamName( $paramName ) );
 189                                 }
 190                         }
 191
 192                         if ( !$isDryRun ) {
 193                                 $this->resolvePendingRedirects();
 194                         }
 195                 } else {
 196                         // Only one of the titles/pageids/revids is allowed at the same time
 197                         $dataSource = null;
 198                         if ( isset( $this->mParams['titles'] ) ) {
 199                                 $dataSource = 'titles';
 200                         }
 201                         if ( isset( $this->mParams['pageids'] ) ) {
 202                                 if ( isset( $dataSource ) ) {
 203                                         $this->dieWithError(
 204                                                 [
 205                                                         'apierror-invalidparammix-cannotusewith',
 206                                                         $this->encodeParamName( 'pageids' ),
 207                                                         $this->encodeParamName( $dataSource )
 208                                                 ],
 209                                                 'multisource'
 210                                         );
 211                                 }
 212                                 $dataSource = 'pageids';
 213                         }
 214                         if ( isset( $this->mParams['revids'] ) ) {
 215                                 if ( isset( $dataSource ) ) {
 216                                         $this->dieWithError(
 217                                                 [
 218                                                         'apierror-invalidparammix-cannotusewith',
 219                                                         $this->encodeParamName( 'revids' ),
 220                                                         $this->encodeParamName( $dataSource )
 221                                                 ],
 222                                                 'multisource'
 223                                         );
 224                                 }
 225                                 $dataSource = 'revids';
 226                         }
 227
 228                         if ( !$isDryRun ) {
 229                                 // Populate page information with the original user input
 230                                 switch ( $dataSource ) {
 231                                         case 'titles':
 232                                                 $this->initFromTitles( $this->mParams['titles'] );
 233                                                 break;
 234                                         case 'pageids':
 235                                                 $this->initFromPageIds( $this->mParams['pageids'] );
 236                                                 break;
 237                                         case 'revids':
 238                                                 if ( $this->mResolveRedirects ) {
 239                                                         $this->addWarning( 'apiwarn-redirectsandrevids' );
 240                                                 }
 241                                                 $this->mResolveRedirects = false;
 242                                                 $this->initFromRevIDs( $this->mParams['revids'] );
 243                                                 break;
 244                                         default:
 245                                                 // Do nothing - some queries do not need any of the data sources.
 246                                                 break;
 247                                 }
 248                         }
 249                 }
 250         }
 251
 252         /**
 253          * Check whether this PageSet is resolving redirects
 254          * @return bool
 255          */
 256         public function isResolvingRedirects() {
 257                 return $this->mResolveRedirects;
 258         }
 259
 260         /**
 261          * Return the parameter name that is the source of data for this PageSet
 262          *
 263          * If multiple source parameters are specified (e.g. titles and pageids),
 264          * one will be named arbitrarily.
 265          *
 266          * @return string|null
 267          */
 268         public function getDataSource() {
 269                 if ( $this->mAllowGenerator && isset( $this->mParams['generator'] ) ) {
 270                         return 'generator';
 271                 }
 272                 if ( isset( $this->mParams['titles'] ) ) {
 273                         return 'titles';
 274                 }
 275                 if ( isset( $this->mParams['pageids'] ) ) {
 276                         return 'pageids';
 277                 }
 278                 if ( isset( $this->mParams['revids'] ) ) {
 279                         return 'revids';
 280                 }
 281
 282                 return null;
 283         }
 284
 285         /**
 286          * Request an additional field from the page table.
 287          * Must be called before execute()
 288          * @param string $fieldName Field name
 289          */
 290         public function requestField( $fieldName ) {
 291                 $this->mRequestedPageFields[$fieldName] = null;
 292         }
 293
 294         /**
 295          * Get the value of a custom field previously requested through
 296          * requestField()
 297          * @param string $fieldName Field name
 298          * @return mixed Field value
 299          */
 300         public function getCustomField( $fieldName ) {
 301                 return $this->mRequestedPageFields[$fieldName];
 302         }
 303
 304         /**
 305          * Get the fields that have to be queried from the page table:
 306          * the ones requested through requestField() and a few basic ones
 307          * we always need
 308          * @return array Array of field names
 309          */
 310         public function getPageTableFields() {
 311                 // Ensure we get minimum required fields
 312                 // DON'T change this order
 313                 $pageFlds = [
 314                         'page_namespace' => null,
 315                         'page_title' => null,
 316                         'page_id' => null,
 317                 ];
 318
 319                 if ( $this->mResolveRedirects ) {
 320                         $pageFlds['page_is_redirect'] = null;
 321                 }
 322
 323                 if ( $this->getConfig()->get( 'ContentHandlerUseDB' ) ) {
 324                         $pageFlds['page_content_model'] = null;
 325                 }
 326
 327                 if ( $this->getConfig()->get( 'PageLanguageUseDB' ) ) {
 328                         $pageFlds['page_lang'] = null;
 329                 }
 330
 331                 foreach ( LinkCache::getSelectFields() as $field ) {
 332                         $pageFlds[$field] = null;
 333                 }
 334
 335                 $pageFlds = array_merge( $pageFlds, $this->mRequestedPageFields );
 336
 337                 return array_keys( $pageFlds );
 338         }
 339
 340         /**
 341          * Returns an array [ns][dbkey] => page_id for all requested titles.
 342          * page_id is a unique negative number in case title was not found.
 343          * Invalid titles will also have negative page IDs and will be in namespace 0
 344          * @return array
 345          */
 346         public function getAllTitlesByNamespace() {
 347                 return $this->mAllPages;
 348         }
 349
 350         /**
 351          * All Title objects provided.
 352          * @return Title[]
 353          */
 354         public function getTitles() {
 355                 return $this->mTitles;
 356         }
 357
 358         /**
 359          * Returns the number of unique pages (not revisions) in the set.
 360          * @return int
 361          */
 362         public function getTitleCount() {
 363                 return count( $this->mTitles );
 364         }
 365
 366         /**
 367          * Returns an array [ns][dbkey] => page_id for all good titles.
 368          * @return array
 369          */
 370         public function getGoodTitlesByNamespace() {
 371                 return $this->mGoodPages;
 372         }
 373
 374         /**
 375          * Title objects that were found in the database.
 376          * @return Title[] Array page_id (int) => Title (obj)
 377          */
 378         public function getGoodTitles() {
 379                 return $this->mGoodTitles;
 380         }
 381
 382         /**
 383          * Returns the number of found unique pages (not revisions) in the set.
 384          * @return int
 385          */
 386         public function getGoodTitleCount() {
 387                 return count( $this->mGoodTitles );
 388         }
 389
 390         /**
 391          * Returns an array [ns][dbkey] => fake_page_id for all missing titles.
 392          * fake_page_id is a unique negative number.
 393          * @return array
 394          */
 395         public function getMissingTitlesByNamespace() {
 396                 return $this->mMissingPages;
 397         }
 398
 399         /**
 400          * Title objects that were NOT found in the database.
 401          * The array's index will be negative for each item
 402          * @return Title[]
 403          */
 404         public function getMissingTitles() {
 405                 return $this->mMissingTitles;
 406         }
 407
 408         /**
 409          * Returns an array [ns][dbkey] => page_id for all good and missing titles.
 410          * @return array
 411          */
 412         public function getGoodAndMissingTitlesByNamespace() {
 413                 return $this->mGoodAndMissingPages;
 414         }
 415
 416         /**
 417          * Title objects for good and missing titles.
 418          * @return array
 419          */
 420         public function getGoodAndMissingTitles() {
 421                 return $this->mGoodTitles + $this->mMissingTitles;
 422         }
 423
 424         /**
 425          * Titles that were deemed invalid by Title::newFromText()
 426          * The array's index will be unique and negative for each item
 427          * @deprecated since 1.26, use self::getInvalidTitlesAndReasons()
 428          * @return string[] Array of strings (not Title objects)
 429          */
 430         public function getInvalidTitles() {
 431                 wfDeprecated( __METHOD__, '1.26' );
 432                 return array_map( function ( $t ) {
 433                         return $t['title'];
 434                 }, $this->mInvalidTitles );
 435         }
 436
 437         /**
 438          * Titles that were deemed invalid by Title::newFromText()
 439          * The array's index will be unique and negative for each item
 440          * @return array[] Array of arrays with 'title' and 'invalidreason' properties
 441          */
 442         public function getInvalidTitlesAndReasons() {
 443                 return $this->mInvalidTitles;
 444         }
 445
 446         /**
 447          * Page IDs that were not found in the database
 448          * @return array Array of page IDs
 449          */
 450         public function getMissingPageIDs() {
 451                 return $this->mMissingPageIDs;
 452         }
 453
 454         /**
 455          * Get a list of redirect resolutions - maps a title to its redirect
 456          * target, as an array of output-ready arrays
 457          * @return Title[]
 458          */
 459         public function getRedirectTitles() {
 460                 return $this->mRedirectTitles;
 461         }
 462
 463         /**
 464          * Get a list of redirect resolutions - maps a title to its redirect
 465          * target. Includes generator data for redirect source when available.
 466          * @param ApiResult $result
 467          * @return array Array of prefixed_title (string) => Title object
 468          * @since 1.21
 469          */
 470         public function getRedirectTitlesAsResult( $result = null ) {
 471                 $values = [];
 472                 foreach ( $this->getRedirectTitles() as $titleStrFrom => $titleTo ) {
 473                         $r = [
 474                                 'from' => strval( $titleStrFrom ),
 475                                 'to' => $titleTo->getPrefixedText(),
 476                         ];
 477                         if ( $titleTo->hasFragment() ) {
 478                                 $r['tofragment'] = $titleTo->getFragment();
 479                         }
 480                         if ( $titleTo->isExternal() ) {
 481                                 $r['tointerwiki'] = $titleTo->getInterwiki();
 482                         }
 483                         if ( isset( $this->mResolvedRedirectTitles[$titleStrFrom] ) ) {
 484                                 $titleFrom = $this->mResolvedRedirectTitles[$titleStrFrom];
 485                                 $ns = $titleFrom->getNamespace();
 486                                 $dbkey = $titleFrom->getDBkey();
 487                                 if ( isset( $this->mGeneratorData[$ns][$dbkey] ) ) {
 488                                         $r = array_merge( $this->mGeneratorData[$ns][$dbkey], $r );
 489                                 }
 490                         }
 491
 492                         $values[] = $r;
 493                 }
 494                 if ( !empty( $values ) && $result ) {
 495                         ApiResult::setIndexedTagName( $values, 'r' );
 496                 }
 497
 498                 return $values;
 499         }
 500
 501         /**
 502          * Get a list of title normalizations - maps a title to its normalized
 503          * version.
 504          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 505          */
 506         public function getNormalizedTitles() {
 507                 return $this->mNormalizedTitles;
 508         }
 509
 510         /**
 511          * Get a list of title normalizations - maps a title to its normalized
 512          * version in the form of result array.
 513          * @param ApiResult $result
 514          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 515          * @since 1.21
 516          */
 517         public function getNormalizedTitlesAsResult( $result = null ) {
 518                 global $wgContLang;
 519
 520                 $values = [];
 521                 foreach ( $this->getNormalizedTitles() as $rawTitleStr => $titleStr ) {
 522                         $encode = ( $wgContLang->normalize( $rawTitleStr ) !== $rawTitleStr );
 523                         $values[] = [
 524                                 'fromencoded' => $encode,
 525                                 'from' => $encode ? rawurlencode( $rawTitleStr ) : $rawTitleStr,
 526                                 'to' => $titleStr
 527                         ];
 528                 }
 529                 if ( !empty( $values ) && $result ) {
 530                         ApiResult::setIndexedTagName( $values, 'n' );
 531                 }
 532
 533                 return $values;
 534         }
 535
 536         /**
 537          * Get a list of title conversions - maps a title to its converted
 538          * version.
 539          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 540          */
 541         public function getConvertedTitles() {
 542                 return $this->mConvertedTitles;
 543         }
 544
 545         /**
 546          * Get a list of title conversions - maps a title to its converted
 547          * version as a result array.
 548          * @param ApiResult $result
 549          * @return array Array of (from, to) strings
 550          * @since 1.21
 551          */
 552         public function getConvertedTitlesAsResult( $result = null ) {
 553                 $values = [];
 554                 foreach ( $this->getConvertedTitles() as $rawTitleStr => $titleStr ) {
 555                         $values[] = [
 556                                 'from' => $rawTitleStr,
 557                                 'to' => $titleStr
 558                         ];
 559                 }
 560                 if ( !empty( $values ) && $result ) {
 561                         ApiResult::setIndexedTagName( $values, 'c' );
 562                 }
 563
 564                 return $values;
 565         }
 566
 567         /**
 568          * Get a list of interwiki titles - maps a title to its interwiki
 569          * prefix.
 570          * @return array Array of raw_prefixed_title (string) => interwiki_prefix (string)
 571          */
 572         public function getInterwikiTitles() {
 573                 return $this->mInterwikiTitles;
 574         }
 575
 576         /**
 577          * Get a list of interwiki titles - maps a title to its interwiki
 578          * prefix as result.
 579          * @param ApiResult $result
 580          * @param bool $iwUrl
 581          * @return array Array of raw_prefixed_title (string) => interwiki_prefix (string)
 582          * @since 1.21
 583          */
 584         public function getInterwikiTitlesAsResult( $result = null, $iwUrl = false ) {
 585                 $values = [];
 586                 foreach ( $this->getInterwikiTitles() as $rawTitleStr => $interwikiStr ) {
 587                         $item = [
 588                                 'title' => $rawTitleStr,
 589                                 'iw' => $interwikiStr,
 590                         ];
 591                         if ( $iwUrl ) {
 592                                 $title = Title::newFromText( $rawTitleStr );
 593                                 $item['url'] = $title->getFullURL( '', false, PROTO_CURRENT );
 594                         }
 595                         $values[] = $item;
 596                 }
 597                 if ( !empty( $values ) && $result ) {
 598                         ApiResult::setIndexedTagName( $values, 'i' );
 599                 }
 600
 601                 return $values;
 602         }
 603
 604         /**
 605          * Get an array of invalid/special/missing titles.
 606          *
 607          * @param array $invalidChecks List of types of invalid titles to include.
 608          *   Recognized values are:
 609          *   - invalidTitles: Titles and reasons from $this->getInvalidTitlesAndReasons()
 610          *   - special: Titles from $this->getSpecialTitles()
 611          *   - missingIds: ids from $this->getMissingPageIDs()
 612          *   - missingRevIds: ids from $this->getMissingRevisionIDs()
 613          *   - missingTitles: Titles from $this->getMissingTitles()
 614          *   - interwikiTitles: Titles from $this->getInterwikiTitlesAsResult()
 615          * @return array Array suitable for inclusion in the response
 616          * @since 1.23
 617          */
 618         public function getInvalidTitlesAndRevisions( $invalidChecks = [ 'invalidTitles',
 619                 'special', 'missingIds', 'missingRevIds', 'missingTitles', 'interwikiTitles' ]
 620         ) {
 621                 $result = [];
 622                 if ( in_array( 'invalidTitles', $invalidChecks ) ) {
 623                         self::addValues( $result, $this->getInvalidTitlesAndReasons(), [ 'invalid' ] );
 624                 }
 625                 if ( in_array( 'special', $invalidChecks ) ) {
 626                         $known = [];
 627                         $unknown = [];
 628                         foreach ( $this->getSpecialTitles() as $title ) {
 629                                 if ( $title->isKnown() ) {
 630                                         $known[] = $title;
 631                                 } else {
 632                                         $unknown[] = $title;
 633                                 }
 634                         }
 635                         self::addValues( $result, $unknown, [ 'special', 'missing' ] );
 636                         self::addValues( $result, $known, [ 'special' ] );
 637                 }
 638                 if ( in_array( 'missingIds', $invalidChecks ) ) {
 639                         self::addValues( $result, $this->getMissingPageIDs(), [ 'missing' ], 'pageid' );
 640                 }
 641                 if ( in_array( 'missingRevIds', $invalidChecks ) ) {
 642                         self::addValues( $result, $this->getMissingRevisionIDs(), [ 'missing' ], 'revid' );
 643                 }
 644                 if ( in_array( 'missingTitles', $invalidChecks ) ) {
 645                         $known = [];
 646                         $unknown = [];
 647                         foreach ( $this->getMissingTitles() as $title ) {
 648                                 if ( $title->isKnown() ) {
 649                                         $known[] = $title;
 650                                 } else {
 651                                         $unknown[] = $title;
 652                                 }
 653                         }
 654                         self::addValues( $result, $unknown, [ 'missing' ] );
 655                         self::addValues( $result, $known, [ 'missing', 'known' ] );
 656                 }
 657                 if ( in_array( 'interwikiTitles', $invalidChecks ) ) {
 658                         self::addValues( $result, $this->getInterwikiTitlesAsResult() );
 659                 }
 660
 661                 return $result;
 662         }
 663
 664         /**
 665          * Get the list of valid revision IDs (requested with the revids= parameter)
 666          * @return array Array of revID (int) => pageID (int)
 667          */
 668         public function getRevisionIDs() {
 669                 return $this->mGoodRevIDs;
 670         }
 671
 672         /**
 673          * Get the list of non-deleted revision IDs (requested with the revids= parameter)
 674          * @return array Array of revID (int) => pageID (int)
 675          */
 676         public function getLiveRevisionIDs() {
 677                 return $this->mLiveRevIDs;
 678         }
 679
 680         /**
 681          * Get the list of revision IDs that were associated with deleted titles.
 682          * @return array Array of revID (int) => pageID (int)
 683          */
 684         public function getDeletedRevisionIDs() {
 685                 return $this->mDeletedRevIDs;
 686         }
 687
 688         /**
 689          * Revision IDs that were not found in the database
 690          * @return array Array of revision IDs
 691          */
 692         public function getMissingRevisionIDs() {
 693                 return $this->mMissingRevIDs;
 694         }
 695
 696         /**
 697          * Revision IDs that were not found in the database as result array.
 698          * @param ApiResult $result
 699          * @return array Array of revision IDs
 700          * @since 1.21
 701          */
 702         public function getMissingRevisionIDsAsResult( $result = null ) {
 703                 $values = [];
 704                 foreach ( $this->getMissingRevisionIDs() as $revid ) {
 705                         $values[$revid] = [
 706                                 'revid' => $revid
 707                         ];
 708                 }
 709                 if ( !empty( $values ) && $result ) {
 710                         ApiResult::setIndexedTagName( $values, 'rev' );
 711                 }
 712
 713                 return $values;
 714         }
 715
 716         /**
 717          * Get the list of titles with negative namespace
 718          * @return Title[]
 719          */
 720         public function getSpecialTitles() {
 721                 return $this->mSpecialTitles;
 722         }
 723
 724         /**
 725          * Returns the number of revisions (requested with revids= parameter).
 726          * @return int Number of revisions.
 727          */
 728         public function getRevisionCount() {
 729                 return count( $this->getRevisionIDs() );
 730         }
 731
 732         /**
 733          * Populate this PageSet from a list of Titles
 734          * @param array $titles Array of Title objects
 735          */
 736         public function populateFromTitles( $titles ) {
 737                 $this->initFromTitles( $titles );
 738         }
 739
 740         /**
 741          * Populate this PageSet from a list of page IDs
 742          * @param array $pageIDs Array of page IDs
 743          */
 744         public function populateFromPageIDs( $pageIDs ) {
 745                 $this->initFromPageIds( $pageIDs );
 746         }
 747
 748         /**
 749          * Populate this PageSet from a rowset returned from the database
 750          *
 751          * Note that the query result must include the columns returned by
 752          * $this->getPageTableFields().
 753          *
 754          * @param IDatabase $db
 755          * @param ResultWrapper $queryResult Query result object
 756          */
 757         public function populateFromQueryResult( $db, $queryResult ) {
 758                 $this->initFromQueryResult( $queryResult );
 759         }
 760
 761         /**
 762          * Populate this PageSet from a list of revision IDs
 763          * @param array $revIDs Array of revision IDs
 764          */
 765         public function populateFromRevisionIDs( $revIDs ) {
 766                 $this->initFromRevIDs( $revIDs );
 767         }
 768
 769         /**
 770          * Extract all requested fields from the row received from the database
 771          * @param stdClass $row Result row
 772          */
 773         public function processDbRow( $row ) {
 774                 // Store Title object in various data structures
 775                 $title = Title::newFromRow( $row );
 776
 777                 LinkCache::singleton()->addGoodLinkObjFromRow( $title, $row );
 778
 779                 $pageId = intval( $row->page_id );
 780                 $this->mAllPages[$row->page_namespace][$row->page_title] = $pageId;
 781                 $this->mTitles[] = $title;
 782
 783                 if ( $this->mResolveRedirects && $row->page_is_redirect == '1' ) {
 784                         $this->mPendingRedirectIDs[$pageId] = $title;
 785                 } else {
 786                         $this->mGoodPages[$row->page_namespace][$row->page_title] = $pageId;
 787                         $this->mGoodAndMissingPages[$row->page_namespace][$row->page_title] = $pageId;
 788                         $this->mGoodTitles[$pageId] = $title;
 789                 }
 790
 791                 foreach ( $this->mRequestedPageFields as $fieldName => &$fieldValues ) {
 792                         $fieldValues[$pageId] = $row->$fieldName;
 793                 }
 794         }
 795
 796         /**
 797          * This method populates internal variables with page information
 798          * based on the given array of title strings.
 799          *
 800          * Steps:
 801          * #1 For each title, get data from `page` table
 802          * #2 If page was not found in the DB, store it as missing
 803          *
 804          * Additionally, when resolving redirects:
 805          * #3 If no more redirects left, stop.
 806          * #4 For each redirect, get its target from the `redirect` table.
 807          * #5 Substitute the original LinkBatch object with the new list
 808          * #6 Repeat from step #1
 809          *
 810          * @param array $titles Array of Title objects or strings
 811          */
 812         private function initFromTitles( $titles ) {
 813                 // Get validated and normalized title objects
 814                 $linkBatch = $this->processTitlesArray( $titles );
 815                 if ( $linkBatch->isEmpty() ) {
 816                         return;
 817                 }
 818
 819                 $db = $this->getDB();
 820                 $set = $linkBatch->constructSet( 'page', $db );
 821
 822                 // Get pageIDs data from the `page` table
 823                 $res = $db->select( 'page', $this->getPageTableFields(), $set,
 824                         __METHOD__ );
 825
 826                 // Hack: get the ns:titles stored in [ ns => [ titles ] ] format
 827                 $this->initFromQueryResult( $res, $linkBatch->data, true ); // process Titles
 828
 829                 // Resolve any found redirects
 830                 $this->resolvePendingRedirects();
 831         }
 832
 833         /**
 834          * Does the same as initFromTitles(), but is based on page IDs instead
 835          * @param array $pageids Array of page IDs
 836          */
 837         private function initFromPageIds( $pageids ) {
 838                 if ( !$pageids ) {
 839                         return;
 840                 }
 841
 842                 $pageids = array_map( 'intval', $pageids ); // paranoia
 843                 $remaining = array_flip( $pageids );
 844
 845                 $pageids = self::getPositiveIntegers( $pageids );
 846
 847                 $res = null;
 848                 if ( !empty( $pageids ) ) {
 849                         $set = [
 850                                 'page_id' => $pageids
 851                         ];
 852                         $db = $this->getDB();
 853
 854                         // Get pageIDs data from the `page` table
 855                         $res = $db->select( 'page', $this->getPageTableFields(), $set,
 856                                 __METHOD__ );
 857                 }
 858
 859                 $this->initFromQueryResult( $res, $remaining, false ); // process PageIDs
 860
 861                 // Resolve any found redirects
 862                 $this->resolvePendingRedirects();
 863         }
 864
 865         /**
 866          * Iterate through the result of the query on 'page' table,
 867          * and for each row create and store title object and save any extra fields requested.
 868          * @param ResultWrapper $res DB Query result
 869          * @param array $remaining Array of either pageID or ns/title elements (optional).
 870          *        If given, any missing items will go to $mMissingPageIDs and $mMissingTitles
 871          * @param bool $processTitles Must be provided together with $remaining.
 872          *        If true, treat $remaining as an array of [ns][title]
 873          *        If false, treat it as an array of [pageIDs]
 874          */
 875         private function initFromQueryResult( $res, &$remaining = null, $processTitles = null ) {
 876                 if ( !is_null( $remaining ) && is_null( $processTitles ) ) {
 877                         ApiBase::dieDebug( __METHOD__, 'Missing $processTitles parameter when $remaining is provided' );
 878                 }
 879
 880                 $usernames = [];
 881                 if ( $res ) {
 882                         foreach ( $res as $row ) {
 883                                 $pageId = intval( $row->page_id );
 884
 885                                 // Remove found page from the list of remaining items
 886                                 if ( isset( $remaining ) ) {
 887                                         if ( $processTitles ) {
 888                                                 unset( $remaining[$row->page_namespace][$row->page_title] );
 889                                         } else {
 890                                                 unset( $remaining[$pageId] );
 891                                         }
 892                                 }
 893
 894                                 // Store any extra fields requested by modules
 895                                 $this->processDbRow( $row );
 896
 897                                 // Need gender information
 898                                 if ( MWNamespace::hasGenderDistinction( $row->page_namespace ) ) {
 899                                         $usernames[] = $row->page_title;
 900                                 }
 901                         }
 902                 }
 903
 904                 if ( isset( $remaining ) ) {
 905                         // Any items left in the $remaining list are added as missing
 906                         if ( $processTitles ) {
 907                                 // The remaining titles in $remaining are non-existent pages
 908                                 $linkCache = LinkCache::singleton();
 909                                 foreach ( $remaining as $ns => $dbkeys ) {
 910                                         foreach ( array_keys( $dbkeys ) as $dbkey ) {
 911                                                 $title = Title::makeTitle( $ns, $dbkey );
 912                                                 $linkCache->addBadLinkObj( $title );
 913                                                 $this->mAllPages[$ns][$dbkey] = $this->mFakePageId;
 914                                                 $this->mMissingPages[$ns][$dbkey] = $this->mFakePageId;
 915                                                 $this->mGoodAndMissingPages[$ns][$dbkey] = $this->mFakePageId;
 916                                                 $this->mMissingTitles[$this->mFakePageId] = $title;
 917                                                 $this->mFakePageId--;
 918                                                 $this->mTitles[] = $title;
 919
 920                                                 // need gender information
 921                                                 if ( MWNamespace::hasGenderDistinction( $ns ) ) {
 922                                                         $usernames[] = $dbkey;
 923                                                 }
 924                                         }
 925                                 }
 926                         } else {
 927                                 // The remaining pageids do not exist
 928                                 if ( !$this->mMissingPageIDs ) {
 929                                         $this->mMissingPageIDs = array_keys( $remaining );
 930                                 } else {
 931                                         $this->mMissingPageIDs = array_merge( $this->mMissingPageIDs, array_keys( $remaining ) );
 932                                 }
 933                         }
 934                 }
 935
 936                 // Get gender information
 937                 $genderCache = MediaWikiServices::getInstance()->getGenderCache();
 938                 $genderCache->doQuery( $usernames, __METHOD__ );
 939         }
 940
 941         /**
 942          * Does the same as initFromTitles(), but is based on revision IDs
 943          * instead
 944          * @param array $revids Array of revision IDs
 945          */
 946         private function initFromRevIDs( $revids ) {
 947                 if ( !$revids ) {
 948                         return;
 949                 }
 950
 951                 $revids = array_map( 'intval', $revids ); // paranoia
 952                 $db = $this->getDB();
 953                 $pageids = [];
 954                 $remaining = array_flip( $revids );
 955
 956                 $revids = self::getPositiveIntegers( $revids );
 957
 958                 if ( !empty( $revids ) ) {
 959                         $tables = [ 'revision', 'page' ];
 960                         $fields = [ 'rev_id', 'rev_page' ];
 961                         $where = [ 'rev_id' => $revids, 'rev_page = page_id' ];
 962
 963                         // Get pageIDs data from the `page` table
 964                         $res = $db->select( $tables, $fields, $where, __METHOD__ );
 965                         foreach ( $res as $row ) {
 966                                 $revid = intval( $row->rev_id );
 967                                 $pageid = intval( $row->rev_page );
 968                                 $this->mGoodRevIDs[$revid] = $pageid;
 969                                 $this->mLiveRevIDs[$revid] = $pageid;
 970                                 $pageids[$pageid] = '';
 971                                 unset( $remaining[$revid] );
 972                         }
 973                 }
 974
 975                 $this->mMissingRevIDs = array_keys( $remaining );
 976
 977                 // Populate all the page information
 978                 $this->initFromPageIds( array_keys( $pageids ) );
 979
 980                 // If the user can see deleted revisions, pull out the corresponding
 981                 // titles from the archive table and include them too. We ignore
 982                 // ar_page_id because deleted revisions are tied by title, not page_id.
 983                 if ( !empty( $this->mMissingRevIDs ) && $this->getUser()->isAllowed( 'deletedhistory' ) ) {
 984                         $remaining = array_flip( $this->mMissingRevIDs );
 985                         $tables = [ 'archive' ];
 986                         $fields = [ 'ar_rev_id', 'ar_namespace', 'ar_title' ];
 987                         $where = [ 'ar_rev_id' => $this->mMissingRevIDs ];
 988
 989                         $res = $db->select( $tables, $fields, $where, __METHOD__ );
 990                         $titles = [];
 991                         foreach ( $res as $row ) {
 992                                 $revid = intval( $row->ar_rev_id );
 993                                 $titles[$revid] = Title::makeTitle( $row->ar_namespace, $row->ar_title );
 994                                 unset( $remaining[$revid] );
 995                         }
 996
 997                         $this->initFromTitles( $titles );
 998
 999                         foreach ( $titles as $revid => $title ) {
1000                                 $ns = $title->getNamespace();
1001                                 $dbkey = $title->getDBkey();
1002
1003                                 // Handle converted titles
1004                                 if ( !isset( $this->mAllPages[$ns][$dbkey] ) &&
1005                                         isset( $this->mConvertedTitles[$title->getPrefixedText()] )
1006                                 ) {
1007                                         $title = Title::newFromText( $this->mConvertedTitles[$title->getPrefixedText()] );
1008                                         $ns = $title->getNamespace();
1009                                         $dbkey = $title->getDBkey();
1010                                 }
1011
1012                                 if ( isset( $this->mAllPages[$ns][$dbkey] ) ) {
1013                                         $this->mGoodRevIDs[$revid] = $this->mAllPages[$ns][$dbkey];
1014                                         $this->mDeletedRevIDs[$revid] = $this->mAllPages[$ns][$dbkey];
1015                                 } else {
1016                                         $remaining[$revid] = true;
1017                                 }
1018                         }
1019
1020                         $this->mMissingRevIDs = array_keys( $remaining );
1021                 }
1022         }
1023
1024         /**
1025          * Resolve any redirects in the result if redirect resolution was
1026          * requested. This function is called repeatedly until all redirects
1027          * have been resolved.
1028          */
1029         private function resolvePendingRedirects() {
1030                 if ( $this->mResolveRedirects ) {
1031                         $db = $this->getDB();
1032                         $pageFlds = $this->getPageTableFields();
1033
1034                         // Repeat until all redirects have been resolved
1035                         // The infinite loop is prevented by keeping all known pages in $this->mAllPages
1036                         while ( $this->mPendingRedirectIDs ) {
1037                                 // Resolve redirects by querying the pagelinks table, and repeat the process
1038                                 // Create a new linkBatch object for the next pass
1039                                 $linkBatch = $this->getRedirectTargets();
1040
1041                                 if ( $linkBatch->isEmpty() ) {
1042                                         break;
1043                                 }
1044
1045                                 $set = $linkBatch->constructSet( 'page', $db );
1046                                 if ( $set === false ) {
1047                                         break;
1048                                 }
1049
1050                                 // Get pageIDs data from the `page` table
1051                                 $res = $db->select( 'page', $pageFlds, $set, __METHOD__ );
1052
1053                                 // Hack: get the ns:titles stored in [ns => array(titles)] format
1054                                 $this->initFromQueryResult( $res, $linkBatch->data, true );
1055                         }
1056                 }
1057         }
1058
1059         /**
1060          * Get the targets of the pending redirects from the database
1061          *
1062          * Also creates entries in the redirect table for redirects that don't
1063          * have one.
1064          * @return LinkBatch
1065          */
1066         private function getRedirectTargets() {
1067                 $titlesToResolve = [];
1068                 $db = $this->getDB();
1069
1070                 $res = $db->select(
1071                         'redirect',
1072                         [
1073                                 'rd_from',
1074                                 'rd_namespace',
1075                                 'rd_fragment',
1076                                 'rd_interwiki',
1077                                 'rd_title'
1078                         ], [ 'rd_from' => array_keys( $this->mPendingRedirectIDs ) ],
1079                         __METHOD__
1080                 );
1081                 foreach ( $res as $row ) {
1082                         $rdfrom = intval( $row->rd_from );
1083                         $from = $this->mPendingRedirectIDs[$rdfrom]->getPrefixedText();
1084                         $to = Title::makeTitle(
1085                                 $row->rd_namespace,
1086                                 $row->rd_title,
1087                                 $row->rd_fragment,
1088                                 $row->rd_interwiki
1089                         );
1090                         $this->mResolvedRedirectTitles[$from] = $this->mPendingRedirectIDs[$rdfrom];
1091                         unset( $this->mPendingRedirectIDs[$rdfrom] );
1092                         if ( $to->isExternal() ) {
1093                                 $this->mInterwikiTitles[$to->getPrefixedText()] = $to->getInterwiki();
1094                         } elseif ( !isset( $this->mAllPages[$to->getNamespace()][$to->getDBkey()] ) ) {
1095                                 $titlesToResolve[] = $to;
1096                         }
1097                         $this->mRedirectTitles[$from] = $to;
1098                 }
1099
1100                 if ( $this->mPendingRedirectIDs ) {
1101                         // We found pages that aren't in the redirect table
1102                         // Add them
1103                         foreach ( $this->mPendingRedirectIDs as $id => $title ) {
1104                                 $page = WikiPage::factory( $title );
1105                                 $rt = $page->insertRedirect();
1106                                 if ( !$rt ) {
1107                                         // What the hell. Let's just ignore this
1108                                         continue;
1109                                 }
1110                                 if ( $rt->isExternal() ) {
1111                                         $this->mInterwikiTitles[$rt->getPrefixedText()] = $rt->getInterwiki();
1112                                 } elseif ( !isset( $this->mAllPages[$rt->getNamespace()][$rt->getDBkey()] ) ) {
1113                                         $titlesToResolve[] = $rt;
1114                                 }
1115                                 $from = $title->getPrefixedText();
1116                                 $this->mResolvedRedirectTitles[$from] = $title;
1117                                 $this->mRedirectTitles[$from] = $rt;
1118                                 unset( $this->mPendingRedirectIDs[$id] );
1119                         }
1120                 }
1121
1122                 return $this->processTitlesArray( $titlesToResolve );
1123         }
1124
1125         /**
1126          * Get the cache mode for the data generated by this module.
1127          * All PageSet users should take into account whether this returns a more-restrictive
1128          * cache mode than the using module itself. For possible return values and other
1129          * details about cache modes, see ApiMain::setCacheMode()
1130          *
1131          * Public caching will only be allowed if *all* the modules that supply
1132          * data for a given request return a cache mode of public.
1133          *
1134          * @param array|null $params
1135          * @return string
1136          * @since 1.21
1137          */
1138         public function getCacheMode( $params = null ) {
1139                 return $this->mCacheMode;
1140         }
1141
1142         /**
1143          * Given an array of title strings, convert them into Title objects.
1144          * Alternatively, an array of Title objects may be given.
1145          * This method validates access rights for the title,
1146          * and appends normalization values to the output.
1147          *
1148          * @param array $titles Array of Title objects or strings
1149          * @return LinkBatch
1150          */
1151         private function processTitlesArray( $titles ) {
1152                 $usernames = [];
1153                 $linkBatch = new LinkBatch();
1154
1155                 foreach ( $titles as $title ) {
1156                         if ( is_string( $title ) ) {
1157                                 try {
1158                                         $titleObj = Title::newFromTextThrow( $title, $this->mDefaultNamespace );
1159                                 } catch ( MalformedTitleException $ex ) {
1160                                         // Handle invalid titles gracefully
1161                                         if ( !isset( $this->mAllPages[0][$title] ) ) {
1162                                                 $this->mAllPages[0][$title] = $this->mFakePageId;
1163                                                 $this->mInvalidTitles[$this->mFakePageId] = [
1164                                                         'title' => $title,
1165                                                         'invalidreason' => $this->getErrorFormatter()->formatException( $ex, [ 'bc' => true ] ),
1166                                                 ];
1167                                                 $this->mFakePageId--;
1168                                         }
1169                                         continue; // There's nothing else we can do
1170                                 }
1171                         } else {
1172                                 $titleObj = $title;
1173                         }
1174                         $unconvertedTitle = $titleObj->getPrefixedText();
1175                         $titleWasConverted = false;
1176                         if ( $titleObj->isExternal() ) {
1177                                 // This title is an interwiki link.
1178                                 $this->mInterwikiTitles[$unconvertedTitle] = $titleObj->getInterwiki();
1179                         } else {
1180                                 // Variants checking
1181                                 global $wgContLang;
1182                                 if ( $this->mConvertTitles &&
1183                                         count( $wgContLang->getVariants() ) > 1 &&
1184                                         !$titleObj->exists()
1185                                 ) {
1186                                         // Language::findVariantLink will modify titleText and titleObj into
1187                                         // the canonical variant if possible
1188                                         $titleText = is_string( $title ) ? $title : $titleObj->getPrefixedText();
1189                                         $wgContLang->findVariantLink( $titleText, $titleObj );
1190                                         $titleWasConverted = $unconvertedTitle !== $titleObj->getPrefixedText();
1191                                 }
1192
1193                                 if ( $titleObj->getNamespace() < 0 ) {
1194                                         // Handle Special and Media pages
1195                                         $titleObj = $titleObj->fixSpecialName();
1196                                         $ns = $titleObj->getNamespace();
1197                                         $dbkey = $titleObj->getDBkey();
1198                                         if ( !isset( $this->mAllSpecials[$ns][$dbkey] ) ) {
1199                                                 $this->mAllSpecials[$ns][$dbkey] = $this->mFakePageId;
1200                                                 $this->mSpecialTitles[$this->mFakePageId] = $titleObj;
1201                                                 $this->mFakePageId--;
1202                                         }
1203                                 } else {
1204                                         // Regular page
1205                                         $linkBatch->addObj( $titleObj );
1206                                 }
1207                         }
1208
1209                         // Make sure we remember the original title that was
1210                         // given to us. This way the caller can correlate new
1211                         // titles with the originally requested when e.g. the
1212                         // namespace is localized or the capitalization is
1213                         // different
1214                         if ( $titleWasConverted ) {
1215                                 $this->mConvertedTitles[$unconvertedTitle] = $titleObj->getPrefixedText();
1216                                 // In this case the page can't be Special.
1217                                 if ( is_string( $title ) && $title !== $unconvertedTitle ) {
1218                                         $this->mNormalizedTitles[$title] = $unconvertedTitle;
1219                                 }
1220                         } elseif ( is_string( $title ) && $title !== $titleObj->getPrefixedText() ) {
1221                                 $this->mNormalizedTitles[$title] = $titleObj->getPrefixedText();
1222                         }
1223
1224                         // Need gender information
1225                         if ( MWNamespace::hasGenderDistinction( $titleObj->getNamespace() ) ) {
1226                                 $usernames[] = $titleObj->getText();
1227                         }
1228                 }
1229                 // Get gender information
1230                 $genderCache = MediaWikiServices::getInstance()->getGenderCache();
1231                 $genderCache->doQuery( $usernames, __METHOD__ );
1232
1233                 return $linkBatch;
1234         }
1235
1236         /**
1237          * Set data for a title.
1238          *
1239          * This data may be extracted into an ApiResult using
1240          * self::populateGeneratorData. This should generally be limited to
1241          * data that is likely to be particularly useful to end users rather than
1242          * just being a dump of everything returned in non-generator mode.
1243          *
1244          * Redirects here will *not* be followed, even if 'redirects' was
1245          * specified, since in the case of multiple redirects we can't know which
1246          * source's data to use on the target.
1247          *
1248          * @param Title $title
1249          * @param array $data
1250          */
1251         public function setGeneratorData( Title $title, array $data ) {
1252                 $ns = $title->getNamespace();
1253                 $dbkey = $title->getDBkey();
1254                 $this->mGeneratorData[$ns][$dbkey] = $data;
1255         }
1256
1257         /**
1258          * Controls how generator data about a redirect source is merged into
1259          * the generator data for the redirect target. When not set no data
1260          * is merged. Note that if multiple titles redirect to the same target
1261          * the order of operations is undefined.
1262          *
1263          * Example to include generated data from redirect in target, prefering
1264          * the data generated for the destination when there is a collision:
1265          * @code
1266          *   $pageSet->setRedirectMergePolicy( function( array $current, array $new ) {
1267          *       return $current + $new;
1268          *   } );
1269          * @endcode
1270          *
1271          * @param callable|null $callable Recieves two array arguments, first the
1272          *  generator data for the redirect target and second the generator data
1273          *  for the redirect source. Returns the resulting generator data to use
1274          *  for the redirect target.
1275          */
1276         public function setRedirectMergePolicy( $callable ) {
1277                 $this->mRedirectMergePolicy = $callable;
1278         }
1279
1280         /**
1281          * Populate the generator data for all titles in the result
1282          *
1283          * The page data may be inserted into an ApiResult object or into an
1284          * associative array. The $path parameter specifies the path within the
1285          * ApiResult or array to find the "pages" node.
1286          *
1287          * The "pages" node itself must be an associative array mapping the page ID
1288          * or fake page ID values returned by this pageset (see
1289          * self::getAllTitlesByNamespace() and self::getSpecialTitles()) to
1290          * associative arrays of page data. Each of those subarrays will have the
1291          * data from self::setGeneratorData() merged in.
1292          *
1293          * Data that was set by self::setGeneratorData() for pages not in the
1294          * "pages" node will be ignored.
1295          *
1296          * @param ApiResult|array &$result
1297          * @param array $path
1298          * @return bool Whether the data fit
1299          */
1300         public function populateGeneratorData( &$result, array $path = [] ) {
1301                 if ( $result instanceof ApiResult ) {
1302                         $data = $result->getResultData( $path );
1303                         if ( $data === null ) {
1304                                 return true;
1305                         }
1306                 } else {
1307                         $data = &$result;
1308                         foreach ( $path as $key ) {
1309                                 if ( !isset( $data[$key] ) ) {
1310                                         // Path isn't in $result, so nothing to add, so everything
1311                                         // "fits"
1312                                         return true;
1313                                 }
1314                                 $data = &$data[$key];
1315                         }
1316                 }
1317                 foreach ( $this->mGeneratorData as $ns => $dbkeys ) {
1318                         if ( $ns === -1 ) {
1319                                 $pages = [];
1320                                 foreach ( $this->mSpecialTitles as $id => $title ) {
1321                                         $pages[$title->getDBkey()] = $id;
1322                                 }
1323                         } else {
1324                                 if ( !isset( $this->mAllPages[$ns] ) ) {
1325                                         // No known titles in the whole namespace. Skip it.
1326                                         continue;
1327                                 }
1328                                 $pages = $this->mAllPages[$ns];
1329                         }
1330                         foreach ( $dbkeys as $dbkey => $genData ) {
1331                                 if ( !isset( $pages[$dbkey] ) ) {
1332                                         // Unknown title. Forget it.
1333                                         continue;
1334                                 }
1335                                 $pageId = $pages[$dbkey];
1336                                 if ( !isset( $data[$pageId] ) ) {
1337                                         // $pageId didn't make it into the result. Ignore it.
1338                                         continue;
1339                                 }
1340
1341                                 if ( $result instanceof ApiResult ) {
1342                                         $path2 = array_merge( $path, [ $pageId ] );
1343                                         foreach ( $genData as $key => $value ) {
1344                                                 if ( !$result->addValue( $path2, $key, $value ) ) {
1345                                                         return false;
1346                                                 }
1347                                         }
1348                                 } else {
1349                                         $data[$pageId] = array_merge( $data[$pageId], $genData );
1350                                 }
1351                         }
1352                 }
1353
1354                 // Merge data generated about redirect titles into the redirect destination
1355                 if ( $this->mRedirectMergePolicy ) {
1356                         foreach ( $this->mResolvedRedirectTitles as $titleFrom ) {
1357                                 $dest = $titleFrom;
1358                                 while ( isset( $this->mRedirectTitles[$dest->getPrefixedText()] ) ) {
1359                                         $dest = $this->mRedirectTitles[$dest->getPrefixedText()];
1360                                 }
1361                                 $fromNs = $titleFrom->getNamespace();
1362                                 $fromDBkey = $titleFrom->getDBkey();
1363                                 $toPageId = $dest->getArticleID();
1364                                 if ( isset( $data[$toPageId] ) &&
1365                                         isset( $this->mGeneratorData[$fromNs][$fromDBkey] )
1366                                 ) {
1367                                         // It is necesary to set both $data and add to $result, if an ApiResult,
1368                                         // to ensure multiple redirects to the same destination are all merged.
1369                                         $data[$toPageId] = call_user_func(
1370                                                 $this->mRedirectMergePolicy,
1371                                                 $data[$toPageId],
1372                                                 $this->mGeneratorData[$fromNs][$fromDBkey]
1373                                         );
1374                                         if ( $result instanceof ApiResult ) {
1375                                                 if ( !$result->addValue( $path, $toPageId, $data[$toPageId], ApiResult::OVERRIDE ) ) {
1376                                                         return false;
1377                                                 }
1378                                         }
1379                                 }
1380                         }
1381                 }
1382
1383                 return true;
1384         }
1385
1386         /**
1387          * Get the database connection (read-only)
1388          * @return Database
1389          */
1390         protected function getDB() {
1391                 return $this->mDbSource->getDB();
1392         }
1393
1394         /**
1395          * Returns the input array of integers with all values < 0 removed
1396          *
1397          * @param array $array
1398          * @return array
1399          */
1400         private static function getPositiveIntegers( $array ) {
1401                 // T27734 API: possible issue with revids validation
1402                 // It seems with a load of revision rows, MySQL gets upset
1403                 // Remove any < 0 integers, as they can't be valid
1404                 foreach ( $array as $i => $int ) {
1405                         if ( $int < 0 ) {
1406                                 unset( $array[$i] );
1407                         }
1408                 }
1409
1410                 return $array;
1411         }
1412
1413         public function getAllowedParams( $flags = 0 ) {
1414                 $result = [
1415                         'titles' => [
1416                                 ApiBase::PARAM_ISMULTI => true,
1417                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-titles',
1418                         ],
1419                         'pageids' => [
1420                                 ApiBase::PARAM_TYPE => 'integer',
1421                                 ApiBase::PARAM_ISMULTI => true,
1422                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-pageids',
1423                         ],
1424                         'revids' => [
1425                                 ApiBase::PARAM_TYPE => 'integer',
1426                                 ApiBase::PARAM_ISMULTI => true,
1427                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-revids',
1428                         ],
1429                         'generator' => [
1430                                 ApiBase::PARAM_TYPE => null,
1431                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-generator',
1432                                 ApiBase::PARAM_SUBMODULE_PARAM_PREFIX => 'g',
1433                         ],
1434                         'redirects' => [
1435                                 ApiBase::PARAM_DFLT => false,
1436                                 ApiBase::PARAM_HELP_MSG => $this->mAllowGenerator
1437                                         ? 'api-pageset-param-redirects-generator'
1438                                         : 'api-pageset-param-redirects-nogenerator',
1439                         ],
1440                         'converttitles' => [
1441                                 ApiBase::PARAM_DFLT => false,
1442                                 ApiBase::PARAM_HELP_MSG => [
1443                                         'api-pageset-param-converttitles',
1444                                         [ Message::listParam( LanguageConverter::$languagesWithVariants, 'text' ) ],
1445                                 ],
1446                         ],
1447                 ];
1448
1449                 if ( !$this->mAllowGenerator ) {
1450                         unset( $result['generator'] );
1451                 } elseif ( $flags & ApiBase::GET_VALUES_FOR_HELP ) {
1452                         $result['generator'][ApiBase::PARAM_TYPE] = 'submodule';
1453                         $result['generator'][ApiBase::PARAM_SUBMODULE_MAP] = $this->getGenerators();
1454                 }
1455
1456                 return $result;
1457         }
1458
1459         protected function handleParamNormalization( $paramName, $value, $rawValue ) {
1460                 parent::handleParamNormalization( $paramName, $value, $rawValue );
1461
1462                 if ( $paramName === 'titles' ) {
1463                         // For the 'titles' parameter, we want to split it like ApiBase would
1464                         // and add any changed titles to $this->mNormalizedTitles
1465                         $value = $this->explodeMultiValue( $value, self::LIMIT_SML2 + 1 );
1466                         $l = count( $value );
1467                         $rawValue = $this->explodeMultiValue( $rawValue, $l );
1468                         for ( $i = 0; $i < $l; $i++ ) {
1469                                 if ( $value[$i] !== $rawValue[$i] ) {
1470                                         $this->mNormalizedTitles[$rawValue[$i]] = $value[$i];
1471                                 }
1472                         }
1473                 }
1474         }
1475
1476         private static $generators = null;
1477
1478         /**
1479          * Get an array of all available generators
1480          * @return array
1481          */
1482         private function getGenerators() {
1483                 if ( self::$generators === null ) {
1484                         $query = $this->mDbSource;
1485                         if ( !( $query instanceof ApiQuery ) ) {
1486                                 // If the parent container of this pageset is not ApiQuery,
1487                                 // we must create it to get module manager
1488                                 $query = $this->getMain()->getModuleManager()->getModule( 'query' );
1489                         }
1490                         $gens = [];
1491                         $prefix = $query->getModulePath() . '+';
1492                         $mgr = $query->getModuleManager();
1493                         foreach ( $mgr->getNamesWithClasses() as $name => $class ) {
1494                                 if ( is_subclass_of( $class, 'ApiQueryGeneratorBase' ) ) {
1495                                         $gens[$name] = $prefix . $name;
1496                                 }
1497                         }
1498                         ksort( $gens );
1499                         self::$generators = $gens;
1500                 }
1501
1502                 return self::$generators;
1503         }
1504 }