includes/parser/ParserOutput.php

   1 <?php
   2
   3 /**
   4  * Output of the PHP parser.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Parser
  23  */
  24
  25 class ParserOutput extends CacheTime {
  26         /**
  27          * Feature flags to indicate to extensions that MediaWiki core supports and
  28          * uses getText() stateless transforms.
  29          *
  30          * @since 1.31
  31          */
  32         const SUPPORTS_STATELESS_TRANSFORMS = 1;
  33
  34         /**
  35          * @since 1.31
  36          */
  37         const SUPPORTS_UNWRAP_TRANSFORM = 1;
  38
  39         /**
  40          * @var string|null $mText The output text
  41          */
  42         public $mText = null;
  43
  44         /**
  45          * @var array $mLanguageLinks List of the full text of language links,
  46          *  in the order they appear.
  47          */
  48         public $mLanguageLinks;
  49
  50         /**
  51          * @var array $mCategories Map of category names to sort keys
  52          */
  53         public $mCategories;
  54
  55         /**
  56          * @var array $mIndicators Page status indicators, usually displayed in top-right corner.
  57          */
  58         public $mIndicators = [];
  59
  60         /**
  61          * @var string $mTitleText Title text of the chosen language variant, as HTML.
  62          */
  63         public $mTitleText;
  64
  65         /**
  66          * @var array $mLinks 2-D map of NS/DBK to ID for the links in the document.
  67          *  ID=zero for broken.
  68          */
  69         public $mLinks = [];
  70
  71         /**
  72          * @var array $mTemplates 2-D map of NS/DBK to ID for the template references.
  73          *  ID=zero for broken.
  74          */
  75         public $mTemplates = [];
  76
  77         /**
  78          * @var array $mTemplateIds 2-D map of NS/DBK to rev ID for the template references.
  79          *  ID=zero for broken.
  80          */
  81         public $mTemplateIds = [];
  82
  83         /**
  84          * @var array $mImages DB keys of the images used, in the array key only
  85          */
  86         public $mImages = [];
  87
  88         /**
  89          * @var array $mFileSearchOptions DB keys of the images used mapped to sha1 and MW timestamp.
  90          */
  91         public $mFileSearchOptions = [];
  92
  93         /**
  94          * @var array $mExternalLinks External link URLs, in the key only.
  95          */
  96         public $mExternalLinks = [];
  97
  98         /**
  99          * @var array $mInterwikiLinks 2-D map of prefix/DBK (in keys only)
 100          *  for the inline interwiki links in the document.
 101          */
 102         public $mInterwikiLinks = [];
 103
 104         /**
 105          * @var bool $mNewSection Show a new section link?
 106          */
 107         public $mNewSection = false;
 108
 109         /**
 110          * @var bool $mHideNewSection Hide the new section link?
 111          */
 112         public $mHideNewSection = false;
 113
 114         /**
 115          * @var bool $mNoGallery No gallery on category page? (__NOGALLERY__).
 116          */
 117         public $mNoGallery = false;
 118
 119         /**
 120          * @var array $mHeadItems Items to put in the <head> section
 121          */
 122         public $mHeadItems = [];
 123
 124         /**
 125          * @var array $mModules Modules to be loaded by ResourceLoader
 126          */
 127         public $mModules = [];
 128
 129         /**
 130          * @var array $mModuleStyles Modules of which only the CSSS will be loaded by ResourceLoader.
 131          */
 132         public $mModuleStyles = [];
 133
 134         /**
 135          * @var array $mJsConfigVars JavaScript config variable for mw.config combined with this page.
 136          */
 137         public $mJsConfigVars = [];
 138
 139         /**
 140          * @var array $mOutputHooks Hook tags as per $wgParserOutputHooks.
 141          */
 142         public $mOutputHooks = [];
 143
 144         /**
 145          * @var array $mWarnings Warning text to be returned to the user.
 146          *  Wikitext formatted, in the key only.
 147          */
 148         public $mWarnings = [];
 149
 150         /**
 151          * @var array $mSections Table of contents
 152          */
 153         public $mSections = [];
 154
 155         /**
 156          * @var array $mProperties Name/value pairs to be cached in the DB.
 157          */
 158         public $mProperties = [];
 159
 160         /**
 161          * @var string $mTOCHTML HTML of the TOC.
 162          */
 163         public $mTOCHTML = '';
 164
 165         /**
 166          * @var string $mTimestamp Timestamp of the revision.
 167          */
 168         public $mTimestamp;
 169
 170         /**
 171          * @var bool $mEnableOOUI Whether OOUI should be enabled.
 172          */
 173         public $mEnableOOUI = false;
 174
 175         /**
 176          * @var string $mIndexPolicy 'index' or 'noindex'?  Any other value will result in no change.
 177          */
 178         private $mIndexPolicy = '';
 179
 180         /**
 181          * @var true[] $mAccessedOptions List of ParserOptions (stored in the keys).
 182          */
 183         private $mAccessedOptions = [];
 184
 185         /**
 186          * @var array $mExtensionData extra data used by extensions.
 187          */
 188         private $mExtensionData = [];
 189
 190         /**
 191          * @var array $mLimitReportData Parser limit report data.
 192          */
 193         private $mLimitReportData = [];
 194
 195         /** @var array Parser limit report data for JSON */
 196         private $mLimitReportJSData = [];
 197
 198         /**
 199          * @var array $mParseStartTime Timestamps for getTimeSinceStart().
 200          */
 201         private $mParseStartTime = [];
 202
 203         /**
 204          * @var bool $mPreventClickjacking Whether to emit X-Frame-Options: DENY.
 205          */
 206         private $mPreventClickjacking = false;
 207
 208         /**
 209          * @var array $mFlags Generic flags.
 210          */
 211         private $mFlags = [];
 212
 213         /** @var int|null Assumed rev ID for {{REVISIONID}} if no revision is set */
 214         private $mSpeculativeRevId;
 215
 216         /** @var int|null Assumed rev timestamp for {{REVISIONTIMESTAMP}} if no revision is set */
 217         private $revisionTimestampUsed;
 218
 219         /** string CSS classes to use for the wrapping div, stored in the array keys.
 220          * If no class is given, no wrapper is added.
 221          */
 222         private $mWrapperDivClasses = [];
 223
 224         /** @var int Upper bound of expiry based on parse duration */
 225         private $mMaxAdaptiveExpiry = INF;
 226
 227         const EDITSECTION_REGEX =
 228                 '#<(?:mw:)?editsection page="(.*?)" section="(.*?)"(?:/>|>(.*?)(</(?:mw:)?editsection>))#s';
 229
 230         // finalizeAdaptiveCacheExpiry() uses TTL = MAX( m * PARSE_TIME + b, MIN_AR_TTL)
 231         // Current values imply that m=3933.333333 and b=-333.333333
 232         // See https://www.nngroup.com/articles/website-response-times/
 233         const PARSE_FAST_SEC = 0.100; // perceived "fast" page parse
 234         const PARSE_SLOW_SEC = 1.0; // perceived "slow" page parse
 235         const FAST_AR_TTL = 60; // adaptive TTL for "fast" pages
 236         const SLOW_AR_TTL = 3600; // adaptive TTL for "slow" pages
 237         const MIN_AR_TTL = 15; // min adaptive TTL (for sanity, pool counter, and edit stashing)
 238
 239         /**
 240          * @param string|null $text HTML. Use null to indicate that this ParserOutput contains only
 241          *        meta-data, and the HTML output is undetermined, as opposed to empty. Passing null
 242          *        here causes hasText() to return false.
 243          * @param array $languageLinks
 244          * @param array $categoryLinks
 245          * @param bool $unused
 246          * @param string $titletext
 247          */
 248         public function __construct( $text = '', $languageLinks = [], $categoryLinks = [],
 249                 $unused = false, $titletext = ''
 250         ) {
 251                 $this->mText = $text;
 252                 $this->mLanguageLinks = $languageLinks;
 253                 $this->mCategories = $categoryLinks;
 254                 $this->mTitleText = $titletext;
 255         }
 256
 257         /**
 258          * Returns true if text was passed to the constructor, or set using setText(). Returns false
 259          * if null was passed to the $text parameter of the constructor to indicate that this
 260          * ParserOutput only contains meta-data, and the HTML output is undetermined.
 261          *
 262          * @since 1.32
 263          *
 264          * @return bool Whether this ParserOutput contains rendered text. If this returns false, the
 265          *         ParserOutput contains meta-data only.
 266          */
 267         public function hasText() {
 268                 return ( $this->mText !== null );
 269         }
 270
 271         /**
 272          * Get the cacheable text with <mw:editsection> markers still in it. The
 273          * return value is suitable for writing back via setText() but is not valid
 274          * for display to the user.
 275          *
 276          * @return string
 277          * @since 1.27
 278          */
 279         public function getRawText() {
 280                 if ( $this->mText === null ) {
 281                         throw new LogicException( 'This ParserOutput contains no text!' );
 282                 }
 283
 284                 return $this->mText;
 285         }
 286
 287         /**
 288          * Get the output HTML
 289          *
 290          * @param array $options (since 1.31) Transformations to apply to the HTML
 291          *  - allowTOC: (bool) Show the TOC, assuming there were enough headings
 292          *     to generate one and `__NOTOC__` wasn't used. Default is true,
 293          *     but might be statefully overridden.
 294          *  - enableSectionEditLinks: (bool) Include section edit links, assuming
 295          *     section edit link tokens are present in the HTML. Default is true,
 296          *     but might be statefully overridden.
 297          *  - unwrap: (bool) Return text without a wrapper div. Default is false,
 298          *    meaning a wrapper div will be added if getWrapperDivClass() returns
 299          *    a non-empty string.
 300          *  - wrapperDivClass: (string) Wrap the output in a div and apply the given
 301          *    CSS class to that div. This overrides the output of getWrapperDivClass().
 302          *    Setting this to an empty string has the same effect as 'unwrap' => true.
 303          *  - deduplicateStyles: (bool) When true, which is the default, `<style>`
 304          *    tags with the `data-mw-deduplicate` attribute set are deduplicated by
 305          *    value of the attribute: all but the first will be replaced by `<link
 306          *    rel="mw-deduplicated-inline-style" href="mw-data:..."/>` tags, where
 307          *    the scheme-specific-part of the href is the (percent-encoded) value
 308          *    of the `data-mw-deduplicate` attribute.
 309          * @return string HTML
 310          * @return-taint escaped
 311          */
 312         public function getText( $options = [] ) {
 313                 $options += [
 314                         'allowTOC' => true,
 315                         'enableSectionEditLinks' => true,
 316                         'unwrap' => false,
 317                         'deduplicateStyles' => true,
 318                         'wrapperDivClass' => $this->getWrapperDivClass(),
 319                 ];
 320                 $text = $this->getRawText();
 321
 322                 Hooks::runWithoutAbort( 'ParserOutputPostCacheTransform', [ $this, &$text, &$options ] );
 323
 324                 if ( $options['wrapperDivClass'] !== '' && !$options['unwrap'] ) {
 325                         $text = Html::rawElement( 'div', [ 'class' => $options['wrapperDivClass'] ], $text );
 326                 }
 327
 328                 if ( $options['enableSectionEditLinks'] ) {
 329                         $text = preg_replace_callback(
 330                                 self::EDITSECTION_REGEX,
 331                                 function ( $m ) {
 332                                         $editsectionPage = Title::newFromText( htmlspecialchars_decode( $m[1] ) );
 333                                         $editsectionSection = htmlspecialchars_decode( $m[2] );
 334                                         $editsectionContent = isset( $m[4] ) ? Sanitizer::decodeCharReferences( $m[3] ) : null;
 335
 336                                         if ( !is_object( $editsectionPage ) ) {
 337                                                 throw new MWException( "Bad parser output text." );
 338                                         }
 339
 340                                         $context = RequestContext::getMain();
 341                                         return $context->getSkin()->doEditSectionLink(
 342                                                 $editsectionPage,
 343                                                 $editsectionSection,
 344                                                 $editsectionContent,
 345                                                 $context->getLanguage()
 346                                         );
 347                                 },
 348                                 $text
 349                         );
 350                 } else {
 351                         $text = preg_replace( self::EDITSECTION_REGEX, '', $text );
 352                 }
 353
 354                 if ( $options['allowTOC'] ) {
 355                         $text = str_replace( [ Parser::TOC_START, Parser::TOC_END ], '', $text );
 356                 } else {
 357                         $text = preg_replace(
 358                                 '#' . preg_quote( Parser::TOC_START, '#' ) . '.*?' . preg_quote( Parser::TOC_END, '#' ) . '#s',
 359                                 '',
 360                                 $text
 361                         );
 362                 }
 363
 364                 if ( $options['deduplicateStyles'] ) {
 365                         $seen = [];
 366                         $text = preg_replace_callback(
 367                                 '#<style\s+([^>]*data-mw-deduplicate\s*=[^>]*)>.*?</style>#s',
 368                                 function ( $m ) use ( &$seen ) {
 369                                         $attr = Sanitizer::decodeTagAttributes( $m[1] );
 370                                         if ( !isset( $attr['data-mw-deduplicate'] ) ) {
 371                                                 return $m[0];
 372                                         }
 373
 374                                         $key = $attr['data-mw-deduplicate'];
 375                                         if ( !isset( $seen[$key] ) ) {
 376                                                 $seen[$key] = true;
 377                                                 return $m[0];
 378                                         }
 379
 380                                         // We were going to use an empty <style> here, but there
 381                                         // was concern that would be too much overhead for browsers.
 382                                         // So let's hope a <link> with a non-standard rel and href isn't
 383                                         // going to be misinterpreted or mangled by any subsequent processing.
 384                                         return Html::element( 'link', [
 385                                                 'rel' => 'mw-deduplicated-inline-style',
 386                                                 'href' => "mw-data:" . wfUrlencode( $key ),
 387                                         ] );
 388                                 },
 389                                 $text
 390                         );
 391                 }
 392
 393                 // Hydrate slot section header placeholders generated by RevisionRenderer.
 394                 $text = preg_replace_callback(
 395                         '#<mw:slotheader>(.*?)</mw:slotheader>#',
 396                         function ( $m ) {
 397                                 $role = htmlspecialchars_decode( $m[1] );
 398                                 // TODO: map to message, using the interface language. Set lang="xyz" accordingly.
 399                                 $headerText = $role;
 400                                 return $headerText;
 401                         },
 402                         $text
 403                 );
 404                 return $text;
 405         }
 406
 407         /**
 408          * Add a CSS class to use for the wrapping div. If no class is given, no wrapper is added.
 409          *
 410          * @param string $class
 411          */
 412         public function addWrapperDivClass( $class ) {
 413                 $this->mWrapperDivClasses[$class] = true;
 414         }
 415
 416         /**
 417          * Clears the CSS class to use for the wrapping div, effectively disabling the wrapper div
 418          * until addWrapperDivClass() is called.
 419          */
 420         public function clearWrapperDivClass() {
 421                 $this->mWrapperDivClasses = [];
 422         }
 423
 424         /**
 425          * Returns the class (or classes) to be used with the wrapper div for this otuput.
 426          * If there is no wrapper class given, no wrapper div should be added.
 427          * The wrapper div is added automatically by getText().
 428          *
 429          * @return string
 430          */
 431         public function getWrapperDivClass() {
 432                 return implode( ' ', array_keys( $this->mWrapperDivClasses ) );
 433         }
 434
 435         /**
 436          * @param int $id
 437          * @since 1.28
 438          */
 439         public function setSpeculativeRevIdUsed( $id ) {
 440                 $this->mSpeculativeRevId = $id;
 441         }
 442
 443         /**
 444          * @return int|null
 445          * @since 1.28
 446          */
 447         public function getSpeculativeRevIdUsed() {
 448                 return $this->mSpeculativeRevId;
 449         }
 450
 451         /**
 452          * @param string $timestamp TS_MW timestamp
 453          * @since 1.34
 454          */
 455         public function setRevisionTimestampUsed( $timestamp ) {
 456                 $this->revisionTimestampUsed = $timestamp;
 457         }
 458
 459         /**
 460          * @return string|null TS_MW timestamp or null if not used
 461          * @since 1.34
 462          */
 463         public function getRevisionTimestampUsed() {
 464                 return $this->revisionTimestampUsed;
 465         }
 466
 467         public function &getLanguageLinks() {
 468                 return $this->mLanguageLinks;
 469         }
 470
 471         public function getInterwikiLinks() {
 472                 return $this->mInterwikiLinks;
 473         }
 474
 475         public function getCategoryLinks() {
 476                 return array_keys( $this->mCategories );
 477         }
 478
 479         public function &getCategories() {
 480                 return $this->mCategories;
 481         }
 482
 483         /**
 484          * @return array
 485          * @since 1.25
 486          */
 487         public function getIndicators() {
 488                 return $this->mIndicators;
 489         }
 490
 491         public function getTitleText() {
 492                 return $this->mTitleText;
 493         }
 494
 495         public function getSections() {
 496                 return $this->mSections;
 497         }
 498
 499         public function &getLinks() {
 500                 return $this->mLinks;
 501         }
 502
 503         public function &getTemplates() {
 504                 return $this->mTemplates;
 505         }
 506
 507         public function &getTemplateIds() {
 508                 return $this->mTemplateIds;
 509         }
 510
 511         public function &getImages() {
 512                 return $this->mImages;
 513         }
 514
 515         public function &getFileSearchOptions() {
 516                 return $this->mFileSearchOptions;
 517         }
 518
 519         public function &getExternalLinks() {
 520                 return $this->mExternalLinks;
 521         }
 522
 523         public function setNoGallery( $value ) {
 524                 $this->mNoGallery = (bool)$value;
 525         }
 526
 527         public function getNoGallery() {
 528                 return $this->mNoGallery;
 529         }
 530
 531         public function getHeadItems() {
 532                 return $this->mHeadItems;
 533         }
 534
 535         public function getModules() {
 536                 return $this->mModules;
 537         }
 538
 539         public function getModuleStyles() {
 540                 return $this->mModuleStyles;
 541         }
 542
 543         /**
 544          * @return array
 545          * @since 1.23
 546          */
 547         public function getJsConfigVars() {
 548                 return $this->mJsConfigVars;
 549         }
 550
 551         public function getOutputHooks() {
 552                 return (array)$this->mOutputHooks;
 553         }
 554
 555         public function getWarnings() {
 556                 return array_keys( $this->mWarnings );
 557         }
 558
 559         public function getIndexPolicy() {
 560                 return $this->mIndexPolicy;
 561         }
 562
 563         public function getTOCHTML() {
 564                 return $this->mTOCHTML;
 565         }
 566
 567         /**
 568          * @return string|null TS_MW timestamp of the revision content
 569          */
 570         public function getTimestamp() {
 571                 return $this->mTimestamp;
 572         }
 573
 574         public function getLimitReportData() {
 575                 return $this->mLimitReportData;
 576         }
 577
 578         public function getLimitReportJSData() {
 579                 return $this->mLimitReportJSData;
 580         }
 581
 582         public function getEnableOOUI() {
 583                 return $this->mEnableOOUI;
 584         }
 585
 586         public function setText( $text ) {
 587                 return wfSetVar( $this->mText, $text );
 588         }
 589
 590         public function setLanguageLinks( $ll ) {
 591                 return wfSetVar( $this->mLanguageLinks, $ll );
 592         }
 593
 594         public function setCategoryLinks( $cl ) {
 595                 return wfSetVar( $this->mCategories, $cl );
 596         }
 597
 598         public function setTitleText( $t ) {
 599                 return wfSetVar( $this->mTitleText, $t );
 600         }
 601
 602         public function setSections( $toc ) {
 603                 return wfSetVar( $this->mSections, $toc );
 604         }
 605
 606         public function setIndexPolicy( $policy ) {
 607                 return wfSetVar( $this->mIndexPolicy, $policy );
 608         }
 609
 610         public function setTOCHTML( $tochtml ) {
 611                 return wfSetVar( $this->mTOCHTML, $tochtml );
 612         }
 613
 614         public function setTimestamp( $timestamp ) {
 615                 return wfSetVar( $this->mTimestamp, $timestamp );
 616         }
 617
 618         public function addCategory( $c, $sort ) {
 619                 $this->mCategories[$c] = $sort;
 620         }
 621
 622         /**
 623          * @param string $id
 624          * @param string $content
 625          * @since 1.25
 626          */
 627         public function setIndicator( $id, $content ) {
 628                 $this->mIndicators[$id] = $content;
 629         }
 630
 631         /**
 632          * Enables OOUI, if true, in any OutputPage instance this ParserOutput
 633          * object is added to.
 634          *
 635          * @since 1.26
 636          * @param bool $enable If OOUI should be enabled or not
 637          */
 638         public function setEnableOOUI( $enable = false ) {
 639                 $this->mEnableOOUI = $enable;
 640         }
 641
 642         public function addLanguageLink( $t ) {
 643                 $this->mLanguageLinks[] = $t;
 644         }
 645
 646         public function addWarning( $s ) {
 647                 $this->mWarnings[$s] = 1;
 648         }
 649
 650         public function addOutputHook( $hook, $data = false ) {
 651                 $this->mOutputHooks[] = [ $hook, $data ];
 652         }
 653
 654         public function setNewSection( $value ) {
 655                 $this->mNewSection = (bool)$value;
 656         }
 657
 658         public function hideNewSection( $value ) {
 659                 $this->mHideNewSection = (bool)$value;
 660         }
 661
 662         public function getHideNewSection() {
 663                 return (bool)$this->mHideNewSection;
 664         }
 665
 666         public function getNewSection() {
 667                 return (bool)$this->mNewSection;
 668         }
 669
 670         /**
 671          * Checks, if a url is pointing to the own server
 672          *
 673          * @param string $internal The server to check against
 674          * @param string $url The url to check
 675          * @return bool
 676          */
 677         public static function isLinkInternal( $internal, $url ) {
 678                 return (bool)preg_match( '/^' .
 679                         # If server is proto relative, check also for http/https links
 680                         ( substr( $internal, 0, 2 ) === '//' ? '(?:https?:)?' : '' ) .
 681                         preg_quote( $internal, '/' ) .
 682                         # check for query/path/anchor or end of link in each case
 683                         '(?:[\?\/\#]|$)/i',
 684                         $url
 685                 );
 686         }
 687
 688         public function addExternalLink( $url ) {
 689                 # We don't register links pointing to our own server, unless... :-)
 690                 global $wgServer, $wgRegisterInternalExternals;
 691
 692                 # Replace unnecessary URL escape codes with the referenced character
 693                 # This prevents spammers from hiding links from the filters
 694                 $url = Parser::normalizeLinkUrl( $url );
 695
 696                 $registerExternalLink = true;
 697                 if ( !$wgRegisterInternalExternals ) {
 698                         $registerExternalLink = !self::isLinkInternal( $wgServer, $url );
 699                 }
 700                 if ( $registerExternalLink ) {
 701                         $this->mExternalLinks[$url] = 1;
 702                 }
 703         }
 704
 705         /**
 706          * Record a local or interwiki inline link for saving in future link tables.
 707          *
 708          * @param Title $title
 709          * @param int|null $id Optional known page_id so we can skip the lookup
 710          */
 711         public function addLink( Title $title, $id = null ) {
 712                 if ( $title->isExternal() ) {
 713                         // Don't record interwikis in pagelinks
 714                         $this->addInterwikiLink( $title );
 715                         return;
 716                 }
 717                 $ns = $title->getNamespace();
 718                 $dbk = $title->getDBkey();
 719                 if ( $ns == NS_MEDIA ) {
 720                         // Normalize this pseudo-alias if it makes it down here...
 721                         $ns = NS_FILE;
 722                 } elseif ( $ns == NS_SPECIAL ) {
 723                         // We don't record Special: links currently
 724                         // It might actually be wise to, but we'd need to do some normalization.
 725                         return;
 726                 } elseif ( $dbk === '' ) {
 727                         // Don't record self links -  [[#Foo]]
 728                         return;
 729                 }
 730                 if ( !isset( $this->mLinks[$ns] ) ) {
 731                         $this->mLinks[$ns] = [];
 732                 }
 733                 if ( is_null( $id ) ) {
 734                         $id = $title->getArticleID();
 735                 }
 736                 $this->mLinks[$ns][$dbk] = $id;
 737         }
 738
 739         /**
 740          * Register a file dependency for this output
 741          * @param string $name Title dbKey
 742          * @param string|false|null $timestamp MW timestamp of file creation (or false if non-existing)
 743          * @param string|false|null $sha1 Base 36 SHA-1 of file (or false if non-existing)
 744          */
 745         public function addImage( $name, $timestamp = null, $sha1 = null ) {
 746                 $this->mImages[$name] = 1;
 747                 if ( $timestamp !== null && $sha1 !== null ) {
 748                         $this->mFileSearchOptions[$name] = [ 'time' => $timestamp, 'sha1' => $sha1 ];
 749                 }
 750         }
 751
 752         /**
 753          * Register a template dependency for this output
 754          * @param Title $title
 755          * @param int $page_id
 756          * @param int $rev_id
 757          */
 758         public function addTemplate( $title, $page_id, $rev_id ) {
 759                 $ns = $title->getNamespace();
 760                 $dbk = $title->getDBkey();
 761                 if ( !isset( $this->mTemplates[$ns] ) ) {
 762                         $this->mTemplates[$ns] = [];
 763                 }
 764                 $this->mTemplates[$ns][$dbk] = $page_id;
 765                 if ( !isset( $this->mTemplateIds[$ns] ) ) {
 766                         $this->mTemplateIds[$ns] = [];
 767                 }
 768                 $this->mTemplateIds[$ns][$dbk] = $rev_id; // For versioning
 769         }
 770
 771         /**
 772          * @param Title $title Title object, must be an interwiki link
 773          * @throws MWException If given invalid input
 774          */
 775         public function addInterwikiLink( $title ) {
 776                 if ( !$title->isExternal() ) {
 777                         throw new MWException( 'Non-interwiki link passed, internal parser error.' );
 778                 }
 779                 $prefix = $title->getInterwiki();
 780                 if ( !isset( $this->mInterwikiLinks[$prefix] ) ) {
 781                         $this->mInterwikiLinks[$prefix] = [];
 782                 }
 783                 $this->mInterwikiLinks[$prefix][$title->getDBkey()] = 1;
 784         }
 785
 786         /**
 787          * Add some text to the "<head>".
 788          * If $tag is set, the section with that tag will only be included once
 789          * in a given page.
 790          * @param string $section
 791          * @param string|bool $tag
 792          */
 793         public function addHeadItem( $section, $tag = false ) {
 794                 if ( $tag !== false ) {
 795                         $this->mHeadItems[$tag] = $section;
 796                 } else {
 797                         $this->mHeadItems[] = $section;
 798                 }
 799         }
 800
 801         /**
 802          * @see OutputPage::addModules
 803          */
 804         public function addModules( $modules ) {
 805                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 806         }
 807
 808         /**
 809          * @see OutputPage::addModuleStyles
 810          */
 811         public function addModuleStyles( $modules ) {
 812                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 813         }
 814
 815         /**
 816          * Add one or more variables to be set in mw.config in JavaScript.
 817          *
 818          * @param string|array $keys Key or array of key/value pairs.
 819          * @param mixed|null $value [optional] Value of the configuration variable.
 820          * @since 1.23
 821          */
 822         public function addJsConfigVars( $keys, $value = null ) {
 823                 if ( is_array( $keys ) ) {
 824                         foreach ( $keys as $key => $value ) {
 825                                 $this->mJsConfigVars[$key] = $value;
 826                         }
 827                         return;
 828                 }
 829
 830                 $this->mJsConfigVars[$keys] = $value;
 831         }
 832
 833         /**
 834          * Copy items from the OutputPage object into this one
 835          *
 836          * @param OutputPage $out
 837          */
 838         public function addOutputPageMetadata( OutputPage $out ) {
 839                 $this->addModules( $out->getModules() );
 840                 $this->addModuleStyles( $out->getModuleStyles() );
 841                 $this->addJsConfigVars( $out->getJsConfigVars() );
 842
 843                 $this->mHeadItems = array_merge( $this->mHeadItems, $out->getHeadItemsArray() );
 844                 $this->mPreventClickjacking = $this->mPreventClickjacking || $out->getPreventClickjacking();
 845         }
 846
 847         /**
 848          * Add a tracking category, getting the title from a system message,
 849          * or print a debug message if the title is invalid.
 850          *
 851          * Any message used with this function should be registered so it will
 852          * show up on Special:TrackingCategories. Core messages should be added
 853          * to SpecialTrackingCategories::$coreTrackingCategories, and extensions
 854          * should add to "TrackingCategories" in their extension.json.
 855          *
 856          * @todo Migrate some code to TrackingCategories
 857          *
 858          * @param string $msg Message key
 859          * @param Title $title title of the page which is being tracked
 860          * @return bool Whether the addition was successful
 861          * @since 1.25
 862          */
 863         public function addTrackingCategory( $msg, $title ) {
 864                 if ( $title->isSpecialPage() ) {
 865                         wfDebug( __METHOD__ . ": Not adding tracking category $msg to special page!\n" );
 866                         return false;
 867                 }
 868
 869                 // Important to parse with correct title (T33469)
 870                 $cat = wfMessage( $msg )
 871                         ->title( $title )
 872                         ->inContentLanguage()
 873                         ->text();
 874
 875                 # Allow tracking categories to be disabled by setting them to "-"
 876                 if ( $cat === '-' ) {
 877                         return false;
 878                 }
 879
 880                 $containerCategory = Title::makeTitleSafe( NS_CATEGORY, $cat );
 881                 if ( $containerCategory ) {
 882                         $this->addCategory( $containerCategory->getDBkey(), $this->getProperty( 'defaultsort' ) ?: '' );
 883                         return true;
 884                 } else {
 885                         wfDebug( __METHOD__ . ": [[MediaWiki:$msg]] is not a valid title!\n" );
 886                         return false;
 887                 }
 888         }
 889
 890         /**
 891          * Override the title to be used for display
 892          *
 893          * @note this is assumed to have been validated
 894          * (check equal normalisation, etc.)
 895          *
 896          * @note this is expected to be safe HTML,
 897          * ready to be served to the client.
 898          *
 899          * @param string $text Desired title text
 900          */
 901         public function setDisplayTitle( $text ) {
 902                 $this->setTitleText( $text );
 903                 $this->setProperty( 'displaytitle', $text );
 904         }
 905
 906         /**
 907          * Get the title to be used for display.
 908          *
 909          * As per the contract of setDisplayTitle(), this is safe HTML,
 910          * ready to be served to the client.
 911          *
 912          * @return string HTML
 913          */
 914         public function getDisplayTitle() {
 915                 $t = $this->getTitleText();
 916                 if ( $t === '' ) {
 917                         return false;
 918                 }
 919                 return $t;
 920         }
 921
 922         /**
 923          * Attach a flag to the output so that it can be checked later to handle special cases
 924          *
 925          * @param string $flag
 926          */
 927         public function setFlag( $flag ) {
 928                 $this->mFlags[$flag] = true;
 929         }
 930
 931         /**
 932          * @param string $flag
 933          * @return bool Whether the given flag was set to signify a special case
 934          */
 935         public function getFlag( $flag ) {
 936                 return isset( $this->mFlags[$flag] );
 937         }
 938
 939         /**
 940          * @return string[] List of flags signifying special cases
 941          * @since 1.34
 942          */
 943         public function getAllFlags() {
 944                 return array_keys( $this->mFlags );
 945         }
 946
 947         /**
 948          * Set a property to be stored in the page_props database table.
 949          *
 950          * page_props is a key value store indexed by the page ID. This allows
 951          * the parser to set a property on a page which can then be quickly
 952          * retrieved given the page ID or via a DB join when given the page
 953          * title.
 954          *
 955          * Since 1.23, page_props are also indexed by numeric value, to allow
 956          * for efficient "top k" queries of pages wrt a given property.
 957          *
 958          * setProperty() is thus used to propagate properties from the parsed
 959          * page to request contexts other than a page view of the currently parsed
 960          * article.
 961          *
 962          * Some applications examples:
 963          *
 964          *   * To implement hidden categories, hiding pages from category listings
 965          *     by storing a property.
 966          *
 967          *   * Overriding the displayed article title (ParserOutput::setDisplayTitle()).
 968          *
 969          *   * To implement image tagging, for example displaying an icon on an
 970          *     image thumbnail to indicate that it is listed for deletion on
 971          *     Wikimedia Commons.
 972          *     This is not actually implemented, yet but would be pretty cool.
 973          *
 974          * @note Do not use setProperty() to set a property which is only used
 975          * in a context where the ParserOutput object itself is already available,
 976          * for example a normal page view. There is no need to save such a property
 977          * in the database since the text is already parsed. You can just hook
 978          * OutputPageParserOutput and get your data out of the ParserOutput object.
 979          *
 980          * If you are writing an extension where you want to set a property in the
 981          * parser which is used by an OutputPageParserOutput hook, you have to
 982          * associate the extension data directly with the ParserOutput object.
 983          * Since MediaWiki 1.21, you can use setExtensionData() to do this:
 984          *
 985          * @par Example:
 986          * @code
 987          *    $parser->getOutput()->setExtensionData( 'my_ext_foo', '...' );
 988          * @endcode
 989          *
 990          * And then later, in OutputPageParserOutput or similar:
 991          *
 992          * @par Example:
 993          * @code
 994          *    $output->getExtensionData( 'my_ext_foo' );
 995          * @endcode
 996          *
 997          * In MediaWiki 1.20 and older, you have to use a custom member variable
 998          * within the ParserOutput object:
 999          *
1000          * @par Example:
1001          * @code
1002          *    $parser->getOutput()->my_ext_foo = '...';
1003          * @endcode
1004          * @param string $name
1005          * @param mixed $value
1006          */
1007         public function setProperty( $name, $value ) {
1008                 $this->mProperties[$name] = $value;
1009         }
1010
1011         /**
1012          * @param string $name The property name to look up.
1013          *
1014          * @return mixed|bool The value previously set using setProperty(). False if null or no value
1015          * was set for the given property name.
1016          *
1017          * @note You need to use getProperties() to check for boolean and null properties.
1018          */
1019         public function getProperty( $name ) {
1020                 return $this->mProperties[$name] ?? false;
1021         }
1022
1023         public function unsetProperty( $name ) {
1024                 unset( $this->mProperties[$name] );
1025         }
1026
1027         public function getProperties() {
1028                 if ( !isset( $this->mProperties ) ) {
1029                         $this->mProperties = [];
1030                 }
1031                 return $this->mProperties;
1032         }
1033
1034         /**
1035          * Returns the options from its ParserOptions which have been taken
1036          * into account to produce this output.
1037          * @return string[]
1038          */
1039         public function getUsedOptions() {
1040                 if ( !isset( $this->mAccessedOptions ) ) {
1041                         return [];
1042                 }
1043                 return array_keys( $this->mAccessedOptions );
1044         }
1045
1046         /**
1047          * Tags a parser option for use in the cache key for this parser output.
1048          * Registered as a watcher at ParserOptions::registerWatcher() by Parser::clearState().
1049          * The information gathered here is available via getUsedOptions(),
1050          * and is used by ParserCache::save().
1051          *
1052          * @see ParserCache::getKey
1053          * @see ParserCache::save
1054          * @see ParserOptions::addExtraKey
1055          * @see ParserOptions::optionsHash
1056          * @param string $option
1057          */
1058         public function recordOption( $option ) {
1059                 $this->mAccessedOptions[$option] = true;
1060         }
1061
1062         /**
1063          * Attaches arbitrary data to this ParserObject. This can be used to store some information in
1064          * the ParserOutput object for later use during page output. The data will be cached along with
1065          * the ParserOutput object, but unlike data set using setProperty(), it is not recorded in the
1066          * database.
1067          *
1068          * This method is provided to overcome the unsafe practice of attaching extra information to a
1069          * ParserObject by directly assigning member variables.
1070          *
1071          * To use setExtensionData() to pass extension information from a hook inside the parser to a
1072          * hook in the page output, use this in the parser hook:
1073          *
1074          * @par Example:
1075          * @code
1076          *    $parser->getOutput()->setExtensionData( 'my_ext_foo', '...' );
1077          * @endcode
1078          *
1079          * And then later, in OutputPageParserOutput or similar:
1080          *
1081          * @par Example:
1082          * @code
1083          *    $output->getExtensionData( 'my_ext_foo' );
1084          * @endcode
1085          *
1086          * In MediaWiki 1.20 and older, you have to use a custom member variable
1087          * within the ParserOutput object:
1088          *
1089          * @par Example:
1090          * @code
1091          *    $parser->getOutput()->my_ext_foo = '...';
1092          * @endcode
1093          *
1094          * @since 1.21
1095          *
1096          * @param string $key The key for accessing the data. Extensions should take care to avoid
1097          *   conflicts in naming keys. It is suggested to use the extension's name as a prefix.
1098          *
1099          * @param mixed $value The value to set. Setting a value to null is equivalent to removing
1100          *   the value.
1101          */
1102         public function setExtensionData( $key, $value ) {
1103                 if ( $value === null ) {
1104                         unset( $this->mExtensionData[$key] );
1105                 } else {
1106                         $this->mExtensionData[$key] = $value;
1107                 }
1108         }
1109
1110         /**
1111          * Gets extensions data previously attached to this ParserOutput using setExtensionData().
1112          * Typically, such data would be set while parsing the page, e.g. by a parser function.
1113          *
1114          * @since 1.21
1115          *
1116          * @param string $key The key to look up.
1117          *
1118          * @return mixed|null The value previously set for the given key using setExtensionData()
1119          *         or null if no value was set for this key.
1120          */
1121         public function getExtensionData( $key ) {
1122                 return $this->mExtensionData[$key] ?? null;
1123         }
1124
1125         private static function getTimes( $clock = null ) {
1126                 $ret = [];
1127                 if ( !$clock || $clock === 'wall' ) {
1128                         $ret['wall'] = microtime( true );
1129                 }
1130                 if ( !$clock || $clock === 'cpu' ) {
1131                         $ru = wfGetRusage();
1132                         if ( $ru ) {
1133                                 $ret['cpu'] = $ru['ru_utime.tv_sec'] + $ru['ru_utime.tv_usec'] / 1e6;
1134                                 $ret['cpu'] += $ru['ru_stime.tv_sec'] + $ru['ru_stime.tv_usec'] / 1e6;
1135                         }
1136                 }
1137                 return $ret;
1138         }
1139
1140         /**
1141          * Resets the parse start timestamps for future calls to getTimeSinceStart()
1142          * @since 1.22
1143          */
1144         public function resetParseStartTime() {
1145                 $this->mParseStartTime = self::getTimes();
1146         }
1147
1148         /**
1149          * Returns the time since resetParseStartTime() was last called
1150          *
1151          * Clocks available are:
1152          *  - wall: Wall clock time
1153          *  - cpu: CPU time (requires getrusage)
1154          *
1155          * @since 1.22
1156          * @param string $clock
1157          * @return float|null
1158          */
1159         public function getTimeSinceStart( $clock ) {
1160                 if ( !isset( $this->mParseStartTime[$clock] ) ) {
1161                         return null;
1162                 }
1163
1164                 $end = self::getTimes( $clock );
1165                 return $end[$clock] - $this->mParseStartTime[$clock];
1166         }
1167
1168         /**
1169          * Sets parser limit report data for a key
1170          *
1171          * The key is used as the prefix for various messages used for formatting:
1172          *  - $key: The label for the field in the limit report
1173          *  - $key-value-text: Message used to format the value in the "NewPP limit
1174          *      report" HTML comment. If missing, uses $key-format.
1175          *  - $key-value-html: Message used to format the value in the preview
1176          *      limit report table. If missing, uses $key-format.
1177          *  - $key-value: Message used to format the value. If missing, uses "$1".
1178          *
1179          * Note that all values are interpreted as wikitext, and so should be
1180          * encoded with htmlspecialchars() as necessary, but should avoid complex
1181          * HTML for sanity of display in the "NewPP limit report" comment.
1182          *
1183          * @since 1.22
1184          * @param string $key Message key
1185          * @param mixed $value Appropriate for Message::params()
1186          */
1187         public function setLimitReportData( $key, $value ) {
1188                 $this->mLimitReportData[$key] = $value;
1189
1190                 if ( is_array( $value ) ) {
1191                         if ( array_keys( $value ) === [ 0, 1 ]
1192                                 && is_numeric( $value[0] )
1193                                 && is_numeric( $value[1] )
1194                         ) {
1195                                 $data = [ 'value' => $value[0], 'limit' => $value[1] ];
1196                         } else {
1197                                 $data = $value;
1198                         }
1199                 } else {
1200                         $data = $value;
1201                 }
1202
1203                 if ( strpos( $key, '-' ) ) {
1204                         list( $ns, $name ) = explode( '-', $key, 2 );
1205                         $this->mLimitReportJSData[$ns][$name] = $data;
1206                 } else {
1207                         $this->mLimitReportJSData[$key] = $data;
1208                 }
1209         }
1210
1211         /**
1212          * Check whether the cache TTL was lowered due to dynamic content
1213          *
1214          * When content is determined by more than hard state (e.g. page edits),
1215          * such as template/file transclusions based on the current timestamp or
1216          * extension tags that generate lists based on queries, this return true.
1217          *
1218          * @return bool
1219          * @since 1.25
1220          */
1221         public function hasDynamicContent() {
1222                 global $wgParserCacheExpireTime;
1223
1224                 return $this->getCacheExpiry() < $wgParserCacheExpireTime;
1225         }
1226
1227         /**
1228          * Get or set the prevent-clickjacking flag
1229          *
1230          * @since 1.24
1231          * @param bool|null $flag New flag value, or null to leave it unchanged
1232          * @return bool Old flag value
1233          */
1234         public function preventClickjacking( $flag = null ) {
1235                 return wfSetVar( $this->mPreventClickjacking, $flag );
1236         }
1237
1238         /**
1239          * Lower the runtime adaptive TTL to at most this value
1240          *
1241          * @param int $ttl
1242          * @since 1.28
1243          */
1244         public function updateRuntimeAdaptiveExpiry( $ttl ) {
1245                 $this->mMaxAdaptiveExpiry = min( $ttl, $this->mMaxAdaptiveExpiry );
1246                 $this->updateCacheExpiry( $ttl );
1247         }
1248
1249         /**
1250          * Call this when parsing is done to lower the TTL based on low parse times
1251          *
1252          * @since 1.28
1253          */
1254         public function finalizeAdaptiveCacheExpiry() {
1255                 if ( is_infinite( $this->mMaxAdaptiveExpiry ) ) {
1256                         return; // not set
1257                 }
1258
1259                 $runtime = $this->getTimeSinceStart( 'wall' );
1260                 if ( is_float( $runtime ) ) {
1261                         $slope = ( self::SLOW_AR_TTL - self::FAST_AR_TTL )
1262                                 / ( self::PARSE_SLOW_SEC - self::PARSE_FAST_SEC );
1263                         // SLOW_AR_TTL = PARSE_SLOW_SEC * $slope + $point
1264                         $point = self::SLOW_AR_TTL - self::PARSE_SLOW_SEC * $slope;
1265
1266                         $adaptiveTTL = min(
1267                                 max( $slope * $runtime + $point, self::MIN_AR_TTL ),
1268                                 $this->mMaxAdaptiveExpiry
1269                         );
1270                         $this->updateCacheExpiry( $adaptiveTTL );
1271                 }
1272         }
1273
1274         public function __sleep() {
1275                 return array_diff(
1276                         array_keys( get_object_vars( $this ) ),
1277                         [ 'mParseStartTime' ]
1278                 );
1279         }
1280
1281         /**
1282          * Merges internal metadata such as flags, accessed options, and profiling info
1283          * from $source into this ParserOutput. This should be used whenever the state of $source
1284          * has any impact on the state of this ParserOutput.
1285          *
1286          * @param ParserOutput $source
1287          */
1288         public function mergeInternalMetaDataFrom( ParserOutput $source ) {
1289                 $this->mOutputHooks = self::mergeList( $this->mOutputHooks, $source->getOutputHooks() );
1290                 $this->mWarnings = self::mergeMap( $this->mWarnings, $source->mWarnings ); // don't use getter
1291                 $this->mTimestamp = $this->useMaxValue( $this->mTimestamp, $source->getTimestamp() );
1292
1293                 if ( $this->mSpeculativeRevId && $source->mSpeculativeRevId
1294                         && $this->mSpeculativeRevId !== $source->mSpeculativeRevId
1295                 ) {
1296                         wfLogWarning(
1297                                 'Inconsistent speculative revision ID encountered while merging parser output!'
1298                         );
1299                 }
1300
1301                 $this->mSpeculativeRevId = $this->useMaxValue(
1302                         $this->mSpeculativeRevId,
1303                         $source->getSpeculativeRevIdUsed()
1304                 );
1305                 $this->mParseStartTime = $this->useEachMinValue(
1306                         $this->mParseStartTime,
1307                         $source->mParseStartTime
1308                 );
1309
1310                 $this->mFlags = self::mergeMap( $this->mFlags, $source->mFlags );
1311                 $this->mAccessedOptions = self::mergeMap( $this->mAccessedOptions, $source->mAccessedOptions );
1312
1313                 // TODO: maintain per-slot limit reports!
1314                 if ( empty( $this->mLimitReportData ) ) {
1315                         $this->mLimitReportData = $source->mLimitReportData;
1316                 }
1317                 if ( empty( $this->mLimitReportJSData ) ) {
1318                         $this->mLimitReportJSData = $source->mLimitReportJSData;
1319                 }
1320         }
1321
1322         /**
1323          * Merges HTML metadata such as head items, JS config vars, and HTTP cache control info
1324          * from $source into this ParserOutput. This should be used whenever the HTML in $source
1325          * has been somehow mered into the HTML of this ParserOutput.
1326          *
1327          * @param ParserOutput $source
1328          */
1329         public function mergeHtmlMetaDataFrom( ParserOutput $source ) {
1330                 // HTML and HTTP
1331                 $this->mHeadItems = self::mergeMixedList( $this->mHeadItems, $source->getHeadItems() );
1332                 $this->mModules = self::mergeList( $this->mModules, $source->getModules() );
1333                 $this->mModuleStyles = self::mergeList( $this->mModuleStyles, $source->getModuleStyles() );
1334                 $this->mJsConfigVars = self::mergeMap( $this->mJsConfigVars, $source->getJsConfigVars() );
1335                 $this->mMaxAdaptiveExpiry = min( $this->mMaxAdaptiveExpiry, $source->mMaxAdaptiveExpiry );
1336
1337                 // "noindex" always wins!
1338                 if ( $this->mIndexPolicy === 'noindex' || $source->mIndexPolicy === 'noindex' ) {
1339                         $this->mIndexPolicy = 'noindex';
1340                 } elseif ( $this->mIndexPolicy !== 'index' ) {
1341                         $this->mIndexPolicy = $source->mIndexPolicy;
1342                 }
1343
1344                 // Skin control
1345                 $this->mNewSection = $this->mNewSection || $source->getNewSection();
1346                 $this->mHideNewSection = $this->mHideNewSection || $source->getHideNewSection();
1347                 $this->mNoGallery = $this->mNoGallery || $source->getNoGallery();
1348                 $this->mEnableOOUI = $this->mEnableOOUI || $source->getEnableOOUI();
1349                 $this->mPreventClickjacking = $this->mPreventClickjacking || $source->preventClickjacking();
1350
1351                 // TODO: we'll have to be smarter about this!
1352                 $this->mSections = array_merge( $this->mSections, $source->getSections() );
1353                 $this->mTOCHTML .= $source->mTOCHTML;
1354
1355                 // XXX: we don't want to concatenate title text, so first write wins.
1356                 // We should use the first *modified* title text, but we don't have the original to check.
1357                 if ( $this->mTitleText === null || $this->mTitleText === '' ) {
1358                         $this->mTitleText = $source->mTitleText;
1359                 }
1360
1361                 // class names are stored in array keys
1362                 $this->mWrapperDivClasses = self::mergeMap(
1363                         $this->mWrapperDivClasses,
1364                         $source->mWrapperDivClasses
1365                 );
1366
1367                 // NOTE: last write wins, same as within one ParserOutput
1368                 $this->mIndicators = self::mergeMap( $this->mIndicators, $source->getIndicators() );
1369
1370                 // NOTE: include extension data in "tracking meta data" as well as "html meta data"!
1371                 // TODO: add a $mergeStrategy parameter to setExtensionData to allow different
1372                 // kinds of extension data to be merged in different ways.
1373                 $this->mExtensionData = self::mergeMap(
1374                         $this->mExtensionData,
1375                         $source->mExtensionData
1376                 );
1377         }
1378
1379         /**
1380          * Merges dependency tracking metadata such as backlinks, images used, and extension data
1381          * from $source into this ParserOutput. This allows dependency tracking to be done for the
1382          * combined output of multiple content slots.
1383          *
1384          * @param ParserOutput $source
1385          */
1386         public function mergeTrackingMetaDataFrom( ParserOutput $source ) {
1387                 $this->mLanguageLinks = self::mergeList( $this->mLanguageLinks, $source->getLanguageLinks() );
1388                 $this->mCategories = self::mergeMap( $this->mCategories, $source->getCategories() );
1389                 $this->mLinks = self::merge2D( $this->mLinks, $source->getLinks() );
1390                 $this->mTemplates = self::merge2D( $this->mTemplates, $source->getTemplates() );
1391                 $this->mTemplateIds = self::merge2D( $this->mTemplateIds, $source->getTemplateIds() );
1392                 $this->mImages = self::mergeMap( $this->mImages, $source->getImages() );
1393                 $this->mFileSearchOptions = self::mergeMap(
1394                         $this->mFileSearchOptions,
1395                         $source->getFileSearchOptions()
1396                 );
1397                 $this->mExternalLinks = self::mergeMap( $this->mExternalLinks, $source->getExternalLinks() );
1398                 $this->mInterwikiLinks = self::merge2D(
1399                         $this->mInterwikiLinks,
1400                         $source->getInterwikiLinks()
1401                 );
1402
1403                 // TODO: add a $mergeStrategy parameter to setProperty to allow different
1404                 // kinds of properties to be merged in different ways.
1405                 $this->mProperties = self::mergeMap( $this->mProperties, $source->getProperties() );
1406
1407                 // NOTE: include extension data in "tracking meta data" as well as "html meta data"!
1408                 // TODO: add a $mergeStrategy parameter to setExtensionData to allow different
1409                 // kinds of extension data to be merged in different ways.
1410                 $this->mExtensionData = self::mergeMap(
1411                         $this->mExtensionData,
1412                         $source->mExtensionData
1413                 );
1414         }
1415
1416         private static function mergeMixedList( array $a, array $b ) {
1417                 return array_unique( array_merge( $a, $b ), SORT_REGULAR );
1418         }
1419
1420         private static function mergeList( array $a, array $b ) {
1421                 return array_values( array_unique( array_merge( $a, $b ), SORT_REGULAR ) );
1422         }
1423
1424         private static function mergeMap( array $a, array $b ) {
1425                 return array_replace( $a, $b );
1426         }
1427
1428         private static function merge2D( array $a, array $b ) {
1429                 $values = [];
1430                 $keys = array_merge( array_keys( $a ), array_keys( $b ) );
1431
1432                 foreach ( $keys as $k ) {
1433                         if ( empty( $a[$k] ) ) {
1434                                 $values[$k] = $b[$k];
1435                         } elseif ( empty( $b[$k] ) ) {
1436                                 $values[$k] = $a[$k];
1437                         } elseif ( is_array( $a[$k] ) && is_array( $b[$k] ) ) {
1438                                 $values[$k] = array_replace( $a[$k], $b[$k] );
1439                         } else {
1440                                 $values[$k] = $b[$k];
1441                         }
1442                 }
1443
1444                 return $values;
1445         }
1446
1447         private static function useEachMinValue( array $a, array $b ) {
1448                 $values = [];
1449                 $keys = array_merge( array_keys( $a ), array_keys( $b ) );
1450
1451                 foreach ( $keys as $k ) {
1452                         if ( is_array( $a[$k] ?? null ) && is_array( $b[$k] ?? null ) ) {
1453                                 $values[$k] = self::useEachMinValue( $a[$k], $b[$k] );
1454                         } else {
1455                                 $values[$k] = self::useMinValue( $a[$k] ?? null, $b[$k] ?? null );
1456                         }
1457                 }
1458
1459                 return $values;
1460         }
1461
1462         private static function useMinValue( $a, $b ) {
1463                 if ( $a === null ) {
1464                         return $b;
1465                 }
1466
1467                 if ( $b === null ) {
1468                         return $a;
1469                 }
1470
1471                 return min( $a, $b );
1472         }
1473
1474         private static function useMaxValue( $a, $b ) {
1475                 if ( $a === null ) {
1476                         return $b;
1477                 }
1478
1479                 if ( $b === null ) {
1480                         return $a;
1481                 }
1482
1483                 return max( $a, $b );
1484         }
1485
1486 }