includes/specialpage/SpecialPage.php

   1 <?php
   2 /**
   3  * Parent class for all special pages.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup SpecialPage
  22  */
  23
  24 use MediaWiki\Auth\AuthManager;
  25 use MediaWiki\Linker\LinkRenderer;
  26 use MediaWiki\MediaWikiServices;
  27 use MediaWiki\Navigation\PrevNextNavigationRenderer;
  28
  29 /**
  30  * Parent class for all special pages.
  31  *
  32  * Includes some static functions for handling the special page list deprecated
  33  * in favor of SpecialPageFactory.
  34  *
  35  * @ingroup SpecialPage
  36  */
  37 class SpecialPage implements MessageLocalizer {
  38         // The canonical name of this special page
  39         // Also used for the default <h1> heading, @see getDescription()
  40         protected $mName;
  41
  42         // The local name of this special page
  43         private $mLocalName;
  44
  45         // Minimum user level required to access this page, or "" for anyone.
  46         // Also used to categorise the pages in Special:Specialpages
  47         protected $mRestriction;
  48
  49         // Listed in Special:Specialpages?
  50         private $mListed;
  51
  52         // Whether or not this special page is being included from an article
  53         protected $mIncluding;
  54
  55         // Whether the special page can be included in an article
  56         protected $mIncludable;
  57
  58         /**
  59          * Current request context
  60          * @var IContextSource
  61          */
  62         protected $mContext;
  63
  64         /**
  65          * @var \MediaWiki\Linker\LinkRenderer|null
  66          */
  67         private $linkRenderer;
  68
  69         /**
  70          * Get a localised Title object for a specified special page name
  71          * If you don't need a full Title object, consider using TitleValue through
  72          * getTitleValueFor() below.
  73          *
  74          * @since 1.9
  75          * @since 1.21 $fragment parameter added
  76          *
  77          * @param string $name
  78          * @param string|bool $subpage Subpage string, or false to not use a subpage
  79          * @param string $fragment The link fragment (after the "#")
  80          * @return Title
  81          * @throws MWException
  82          */
  83         public static function getTitleFor( $name, $subpage = false, $fragment = '' ) {
  84                 return Title::newFromTitleValue(
  85                         self::getTitleValueFor( $name, $subpage, $fragment )
  86                 );
  87         }
  88
  89         /**
  90          * Get a localised TitleValue object for a specified special page name
  91          *
  92          * @since 1.28
  93          * @param string $name
  94          * @param string|bool $subpage Subpage string, or false to not use a subpage
  95          * @param string $fragment The link fragment (after the "#")
  96          * @return TitleValue
  97          */
  98         public static function getTitleValueFor( $name, $subpage = false, $fragment = '' ) {
  99                 $name = MediaWikiServices::getInstance()->getSpecialPageFactory()->
 100                         getLocalNameFor( $name, $subpage );
 101
 102                 return new TitleValue( NS_SPECIAL, $name, $fragment );
 103         }
 104
 105         /**
 106          * Get a localised Title object for a page name with a possibly unvalidated subpage
 107          *
 108          * @param string $name
 109          * @param string|bool $subpage Subpage string, or false to not use a subpage
 110          * @return Title|null Title object or null if the page doesn't exist
 111          */
 112         public static function getSafeTitleFor( $name, $subpage = false ) {
 113                 $name = MediaWikiServices::getInstance()->getSpecialPageFactory()->
 114                         getLocalNameFor( $name, $subpage );
 115                 if ( $name ) {
 116                         return Title::makeTitleSafe( NS_SPECIAL, $name );
 117                 } else {
 118                         return null;
 119                 }
 120         }
 121
 122         /**
 123          * Default constructor for special pages
 124          * Derivative classes should call this from their constructor
 125          *     Note that if the user does not have the required level, an error message will
 126          *     be displayed by the default execute() method, without the global function ever
 127          *     being called.
 128          *
 129          *     If you override execute(), you can recover the default behavior with userCanExecute()
 130          *     and displayRestrictionError()
 131          *
 132          * @param string $name Name of the special page, as seen in links and URLs
 133          * @param string $restriction User right required, e.g. "block" or "delete"
 134          * @param bool $listed Whether the page is listed in Special:Specialpages
 135          * @param callable|bool $function Unused
 136          * @param string $file Unused
 137          * @param bool $includable Whether the page can be included in normal pages
 138          */
 139         public function __construct(
 140                 $name = '', $restriction = '', $listed = true,
 141                 $function = false, $file = '', $includable = false
 142         ) {
 143                 $this->mName = $name;
 144                 $this->mRestriction = $restriction;
 145                 $this->mListed = $listed;
 146                 $this->mIncludable = $includable;
 147         }
 148
 149         /**
 150          * Get the name of this Special Page.
 151          * @return string
 152          */
 153         function getName() {
 154                 return $this->mName;
 155         }
 156
 157         /**
 158          * Get the permission that a user must have to execute this page
 159          * @return string
 160          */
 161         function getRestriction() {
 162                 return $this->mRestriction;
 163         }
 164
 165         // @todo FIXME: Decide which syntax to use for this, and stick to it
 166
 167         /**
 168          * Whether this special page is listed in Special:SpecialPages
 169          * @since 1.3 (r3583)
 170          * @return bool
 171          */
 172         function isListed() {
 173                 return $this->mListed;
 174         }
 175
 176         /**
 177          * Set whether this page is listed in Special:Specialpages, at run-time
 178          * @since 1.3
 179          * @param bool $listed
 180          * @return bool
 181          */
 182         function setListed( $listed ) {
 183                 return wfSetVar( $this->mListed, $listed );
 184         }
 185
 186         /**
 187          * Get or set whether this special page is listed in Special:SpecialPages
 188          * @since 1.6
 189          * @param bool|null $x
 190          * @return bool
 191          */
 192         function listed( $x = null ) {
 193                 return wfSetVar( $this->mListed, $x );
 194         }
 195
 196         /**
 197          * Whether it's allowed to transclude the special page via {{Special:Foo/params}}
 198          * @return bool
 199          */
 200         public function isIncludable() {
 201                 return $this->mIncludable;
 202         }
 203
 204         /**
 205          * How long to cache page when it is being included.
 206          *
 207          * @note If cache time is not 0, then the current user becomes an anon
 208          *   if you want to do any per-user customizations, than this method
 209          *   must be overriden to return 0.
 210          * @since 1.26
 211          * @return int Time in seconds, 0 to disable caching altogether,
 212          *  false to use the parent page's cache settings
 213          */
 214         public function maxIncludeCacheTime() {
 215                 return $this->getConfig()->get( 'MiserMode' ) ? $this->getCacheTTL() : 0;
 216         }
 217
 218         /**
 219          * @return int Seconds that this page can be cached
 220          */
 221         protected function getCacheTTL() {
 222                 return 60 * 60;
 223         }
 224
 225         /**
 226          * Whether the special page is being evaluated via transclusion
 227          * @param bool|null $x
 228          * @return bool
 229          */
 230         function including( $x = null ) {
 231                 return wfSetVar( $this->mIncluding, $x );
 232         }
 233
 234         /**
 235          * Get the localised name of the special page
 236          * @return string
 237          */
 238         function getLocalName() {
 239                 if ( !isset( $this->mLocalName ) ) {
 240                         $this->mLocalName = MediaWikiServices::getInstance()->getSpecialPageFactory()->
 241                                 getLocalNameFor( $this->mName );
 242                 }
 243
 244                 return $this->mLocalName;
 245         }
 246
 247         /**
 248          * Is this page expensive (for some definition of expensive)?
 249          * Expensive pages are disabled or cached in miser mode.  Originally used
 250          * (and still overridden) by QueryPage and subclasses, moved here so that
 251          * Special:SpecialPages can safely call it for all special pages.
 252          *
 253          * @return bool
 254          */
 255         public function isExpensive() {
 256                 return false;
 257         }
 258
 259         /**
 260          * Is this page cached?
 261          * Expensive pages are cached or disabled in miser mode.
 262          * Used by QueryPage and subclasses, moved here so that
 263          * Special:SpecialPages can safely call it for all special pages.
 264          *
 265          * @return bool
 266          * @since 1.21
 267          */
 268         public function isCached() {
 269                 return false;
 270         }
 271
 272         /**
 273          * Can be overridden by subclasses with more complicated permissions
 274          * schemes.
 275          *
 276          * @return bool Should the page be displayed with the restricted-access
 277          *   pages?
 278          */
 279         public function isRestricted() {
 280                 // DWIM: If anons can do something, then it is not restricted
 281                 return $this->mRestriction != '' && !User::groupHasPermission( '*', $this->mRestriction );
 282         }
 283
 284         /**
 285          * Checks if the given user (identified by an object) can execute this
 286          * special page (as defined by $mRestriction).  Can be overridden by sub-
 287          * classes with more complicated permissions schemes.
 288          *
 289          * @param User $user The user to check
 290          * @return bool Does the user have permission to view the page?
 291          */
 292         public function userCanExecute( User $user ) {
 293                 return $user->isAllowed( $this->mRestriction );
 294         }
 295
 296         /**
 297          * Output an error message telling the user what access level they have to have
 298          * @throws PermissionsError
 299          */
 300         function displayRestrictionError() {
 301                 throw new PermissionsError( $this->mRestriction );
 302         }
 303
 304         /**
 305          * Checks if userCanExecute, and if not throws a PermissionsError
 306          *
 307          * @since 1.19
 308          * @return void
 309          * @throws PermissionsError
 310          */
 311         public function checkPermissions() {
 312                 if ( !$this->userCanExecute( $this->getUser() ) ) {
 313                         $this->displayRestrictionError();
 314                 }
 315         }
 316
 317         /**
 318          * If the wiki is currently in readonly mode, throws a ReadOnlyError
 319          *
 320          * @since 1.19
 321          * @return void
 322          * @throws ReadOnlyError
 323          */
 324         public function checkReadOnly() {
 325                 if ( wfReadOnly() ) {
 326                         throw new ReadOnlyError;
 327                 }
 328         }
 329
 330         /**
 331          * If the user is not logged in, throws UserNotLoggedIn error
 332          *
 333          * The user will be redirected to Special:Userlogin with the given message as an error on
 334          * the form.
 335          *
 336          * @since 1.23
 337          * @param string $reasonMsg [optional] Message key to be displayed on login page
 338          * @param string $titleMsg [optional] Passed on to UserNotLoggedIn constructor
 339          * @throws UserNotLoggedIn
 340          */
 341         public function requireLogin(
 342                 $reasonMsg = 'exception-nologin-text', $titleMsg = 'exception-nologin'
 343         ) {
 344                 if ( $this->getUser()->isAnon() ) {
 345                         throw new UserNotLoggedIn( $reasonMsg, $titleMsg );
 346                 }
 347         }
 348
 349         /**
 350          * Tells if the special page does something security-sensitive and needs extra defense against
 351          * a stolen account (e.g. a reauthentication). What exactly that will mean is decided by the
 352          * authentication framework.
 353          * @return bool|string False or the argument for AuthManager::securitySensitiveOperationStatus().
 354          *   Typically a special page needing elevated security would return its name here.
 355          */
 356         protected function getLoginSecurityLevel() {
 357                 return false;
 358         }
 359
 360         /**
 361          * Record preserved POST data after a reauthentication.
 362          *
 363          * This is called from checkLoginSecurityLevel() when returning from the
 364          * redirect for reauthentication, if the redirect had been served in
 365          * response to a POST request.
 366          *
 367          * The base SpecialPage implementation does nothing. If your subclass uses
 368          * getLoginSecurityLevel() or checkLoginSecurityLevel(), it should probably
 369          * implement this to do something with the data.
 370          *
 371          * @since 1.32
 372          * @param array $data
 373          */
 374         protected function setReauthPostData( array $data ) {
 375         }
 376
 377         /**
 378          * Verifies that the user meets the security level, possibly reauthenticating them in the process.
 379          *
 380          * This should be used when the page does something security-sensitive and needs extra defense
 381          * against a stolen account (e.g. a reauthentication). The authentication framework will make
 382          * an extra effort to make sure the user account is not compromised. What that exactly means
 383          * will depend on the system and user settings; e.g. the user might be required to log in again
 384          * unless their last login happened recently, or they might be given a second-factor challenge.
 385          *
 386          * Calling this method will result in one if these actions:
 387          * - return true: all good.
 388          * - return false and set a redirect: caller should abort; the redirect will take the user
 389          *   to the login page for reauthentication, and back.
 390          * - throw an exception if there is no way for the user to meet the requirements without using
 391          *   a different access method (e.g. this functionality is only available from a specific IP).
 392          *
 393          * Note that this does not in any way check that the user is authorized to use this special page
 394          * (use checkPermissions() for that).
 395          *
 396          * @param string|null $level A security level. Can be an arbitrary string, defaults to the page
 397          *   name.
 398          * @return bool False means a redirect to the reauthentication page has been set and processing
 399          *   of the special page should be aborted.
 400          * @throws ErrorPageError If the security level cannot be met, even with reauthentication.
 401          */
 402         protected function checkLoginSecurityLevel( $level = null ) {
 403                 $level = $level ?: $this->getName();
 404                 $key = 'SpecialPage:reauth:' . $this->getName();
 405                 $request = $this->getRequest();
 406
 407                 $securityStatus = AuthManager::singleton()->securitySensitiveOperationStatus( $level );
 408                 if ( $securityStatus === AuthManager::SEC_OK ) {
 409                         $uniqueId = $request->getVal( 'postUniqueId' );
 410                         if ( $uniqueId ) {
 411                                 $key .= ':' . $uniqueId;
 412                                 $session = $request->getSession();
 413                                 $data = $session->getSecret( $key );
 414                                 if ( $data ) {
 415                                         $session->remove( $key );
 416                                         $this->setReauthPostData( $data );
 417                                 }
 418                         }
 419                         return true;
 420                 } elseif ( $securityStatus === AuthManager::SEC_REAUTH ) {
 421                         $title = self::getTitleFor( 'Userlogin' );
 422                         $queryParams = $request->getQueryValues();
 423
 424                         if ( $request->wasPosted() ) {
 425                                 $data = array_diff_assoc( $request->getValues(), $request->getQueryValues() );
 426                                 if ( $data ) {
 427                                         // unique ID in case the same special page is open in multiple browser tabs
 428                                         $uniqueId = MWCryptRand::generateHex( 6 );
 429                                         $key .= ':' . $uniqueId;
 430                                         $queryParams['postUniqueId'] = $uniqueId;
 431                                         $session = $request->getSession();
 432                                         $session->persist(); // Just in case
 433                                         $session->setSecret( $key, $data );
 434                                 }
 435                         }
 436
 437                         $query = [
 438                                 'returnto' => $this->getFullTitle()->getPrefixedDBkey(),
 439                                 'returntoquery' => wfArrayToCgi( array_diff_key( $queryParams, [ 'title' => true ] ) ),
 440                                 'force' => $level,
 441                         ];
 442                         $url = $title->getFullURL( $query, false, PROTO_HTTPS );
 443
 444                         $this->getOutput()->redirect( $url );
 445                         return false;
 446                 }
 447
 448                 $titleMessage = wfMessage( 'specialpage-securitylevel-not-allowed-title' );
 449                 $errorMessage = wfMessage( 'specialpage-securitylevel-not-allowed' );
 450                 throw new ErrorPageError( $titleMessage, $errorMessage );
 451         }
 452
 453         /**
 454          * Return an array of subpages beginning with $search that this special page will accept.
 455          *
 456          * For example, if a page supports subpages "foo", "bar" and "baz" (as in Special:PageName/foo,
 457          * etc.):
 458          *
 459          *   - `prefixSearchSubpages( "ba" )` should return `[ "bar", "baz" ]`
 460          *   - `prefixSearchSubpages( "f" )` should return `[ "foo" ]`
 461          *   - `prefixSearchSubpages( "z" )` should return `[]`
 462          *   - `prefixSearchSubpages( "" )` should return `[ foo", "bar", "baz" ]`
 463          *
 464          * @param string $search Prefix to search for
 465          * @param int $limit Maximum number of results to return (usually 10)
 466          * @param int $offset Number of results to skip (usually 0)
 467          * @return string[] Matching subpages
 468          */
 469         public function prefixSearchSubpages( $search, $limit, $offset ) {
 470                 $subpages = $this->getSubpagesForPrefixSearch();
 471                 if ( !$subpages ) {
 472                         return [];
 473                 }
 474
 475                 return self::prefixSearchArray( $search, $limit, $subpages, $offset );
 476         }
 477
 478         /**
 479          * Return an array of subpages that this special page will accept for prefix
 480          * searches. If this method requires a query you might instead want to implement
 481          * prefixSearchSubpages() directly so you can support $limit and $offset. This
 482          * method is better for static-ish lists of things.
 483          *
 484          * @return string[] subpages to search from
 485          */
 486         protected function getSubpagesForPrefixSearch() {
 487                 return [];
 488         }
 489
 490         /**
 491          * Perform a regular substring search for prefixSearchSubpages
 492          * @param string $search Prefix to search for
 493          * @param int $limit Maximum number of results to return (usually 10)
 494          * @param int $offset Number of results to skip (usually 0)
 495          * @return string[] Matching subpages
 496          */
 497         protected function prefixSearchString( $search, $limit, $offset ) {
 498                 $title = Title::newFromText( $search );
 499                 if ( !$title || !$title->canExist() ) {
 500                         // No prefix suggestion in special and media namespace
 501                         return [];
 502                 }
 503
 504                 $searchEngine = MediaWikiServices::getInstance()->newSearchEngine();
 505                 $searchEngine->setLimitOffset( $limit, $offset );
 506                 $searchEngine->setNamespaces( [] );
 507                 $result = $searchEngine->defaultPrefixSearch( $search );
 508                 return array_map( function ( Title $t ) {
 509                         return $t->getPrefixedText();
 510                 }, $result );
 511         }
 512
 513         /**
 514          * Helper function for implementations of prefixSearchSubpages() that
 515          * filter the values in memory (as opposed to making a query).
 516          *
 517          * @since 1.24
 518          * @param string $search
 519          * @param int $limit
 520          * @param array $subpages
 521          * @param int $offset
 522          * @return string[]
 523          */
 524         protected static function prefixSearchArray( $search, $limit, array $subpages, $offset ) {
 525                 $escaped = preg_quote( $search, '/' );
 526                 return array_slice( preg_grep( "/^$escaped/i",
 527                         array_slice( $subpages, $offset ) ), 0, $limit );
 528         }
 529
 530         /**
 531          * Sets headers - this should be called from the execute() method of all derived classes!
 532          */
 533         function setHeaders() {
 534                 $out = $this->getOutput();
 535                 $out->setArticleRelated( false );
 536                 $out->setRobotPolicy( $this->getRobotPolicy() );
 537                 $out->setPageTitle( $this->getDescription() );
 538                 if ( $this->getConfig()->get( 'UseMediaWikiUIEverywhere' ) ) {
 539                         $out->addModuleStyles( [
 540                                 'mediawiki.ui.input',
 541                                 'mediawiki.ui.radio',
 542                                 'mediawiki.ui.checkbox',
 543                         ] );
 544                 }
 545         }
 546
 547         /**
 548          * Entry point.
 549          *
 550          * @since 1.20
 551          *
 552          * @param string|null $subPage
 553          */
 554         final public function run( $subPage ) {
 555                 /**
 556                  * Gets called before @see SpecialPage::execute.
 557                  * Return false to prevent calling execute() (since 1.27+).
 558                  *
 559                  * @since 1.20
 560                  *
 561                  * @param SpecialPage $this
 562                  * @param string|null $subPage
 563                  */
 564                 if ( !Hooks::run( 'SpecialPageBeforeExecute', [ $this, $subPage ] ) ) {
 565                         return;
 566                 }
 567
 568                 if ( $this->beforeExecute( $subPage ) === false ) {
 569                         return;
 570                 }
 571                 $this->execute( $subPage );
 572                 $this->afterExecute( $subPage );
 573
 574                 /**
 575                  * Gets called after @see SpecialPage::execute.
 576                  *
 577                  * @since 1.20
 578                  *
 579                  * @param SpecialPage $this
 580                  * @param string|null $subPage
 581                  */
 582                 Hooks::run( 'SpecialPageAfterExecute', [ $this, $subPage ] );
 583         }
 584
 585         /**
 586          * Gets called before @see SpecialPage::execute.
 587          * Return false to prevent calling execute() (since 1.27+).
 588          *
 589          * @since 1.20
 590          *
 591          * @param string|null $subPage
 592          * @return bool|void
 593          */
 594         protected function beforeExecute( $subPage ) {
 595                 // No-op
 596         }
 597
 598         /**
 599          * Gets called after @see SpecialPage::execute.
 600          *
 601          * @since 1.20
 602          *
 603          * @param string|null $subPage
 604          */
 605         protected function afterExecute( $subPage ) {
 606                 // No-op
 607         }
 608
 609         /**
 610          * Default execute method
 611          * Checks user permissions
 612          *
 613          * This must be overridden by subclasses; it will be made abstract in a future version
 614          *
 615          * @param string|null $subPage
 616          */
 617         public function execute( $subPage ) {
 618                 $this->setHeaders();
 619                 $this->checkPermissions();
 620                 $securityLevel = $this->getLoginSecurityLevel();
 621                 if ( $securityLevel !== false && !$this->checkLoginSecurityLevel( $securityLevel ) ) {
 622                         return;
 623                 }
 624                 $this->outputHeader();
 625         }
 626
 627         /**
 628          * Outputs a summary message on top of special pages
 629          * Per default the message key is the canonical name of the special page
 630          * May be overridden, i.e. by extensions to stick with the naming conventions
 631          * for message keys: 'extensionname-xxx'
 632          *
 633          * @param string $summaryMessageKey Message key of the summary
 634          */
 635         function outputHeader( $summaryMessageKey = '' ) {
 636                 if ( $summaryMessageKey == '' ) {
 637                         $msg = MediaWikiServices::getInstance()->getContentLanguage()->lc( $this->getName() ) .
 638                                 '-summary';
 639                 } else {
 640                         $msg = $summaryMessageKey;
 641                 }
 642                 if ( !$this->msg( $msg )->isDisabled() && !$this->including() ) {
 643                         $this->getOutput()->wrapWikiMsg(
 644                                 "<div class='mw-specialpage-summary'>\n$1\n</div>", $msg );
 645                 }
 646         }
 647
 648         /**
 649          * Returns the name that goes in the \<h1\> in the special page itself, and
 650          * also the name that will be listed in Special:Specialpages
 651          *
 652          * Derived classes can override this, but usually it is easier to keep the
 653          * default behavior.
 654          *
 655          * @return string
 656          */
 657         function getDescription() {
 658                 return $this->msg( strtolower( $this->mName ) )->text();
 659         }
 660
 661         /**
 662          * Get a self-referential title object
 663          *
 664          * @param string|bool $subpage
 665          * @return Title
 666          * @since 1.23
 667          */
 668         function getPageTitle( $subpage = false ) {
 669                 return self::getTitleFor( $this->mName, $subpage );
 670         }
 671
 672         /**
 673          * Sets the context this SpecialPage is executed in
 674          *
 675          * @param IContextSource $context
 676          * @since 1.18
 677          */
 678         public function setContext( $context ) {
 679                 $this->mContext = $context;
 680         }
 681
 682         /**
 683          * Gets the context this SpecialPage is executed in
 684          *
 685          * @return IContextSource|RequestContext
 686          * @since 1.18
 687          */
 688         public function getContext() {
 689                 if ( $this->mContext instanceof IContextSource ) {
 690                         return $this->mContext;
 691                 } else {
 692                         wfDebug( __METHOD__ . " called and \$mContext is null. " .
 693                                 "Return RequestContext::getMain(); for sanity\n" );
 694
 695                         return RequestContext::getMain();
 696                 }
 697         }
 698
 699         /**
 700          * Get the WebRequest being used for this instance
 701          *
 702          * @return WebRequest
 703          * @since 1.18
 704          */
 705         public function getRequest() {
 706                 return $this->getContext()->getRequest();
 707         }
 708
 709         /**
 710          * Get the OutputPage being used for this instance
 711          *
 712          * @return OutputPage
 713          * @since 1.18
 714          */
 715         public function getOutput() {
 716                 return $this->getContext()->getOutput();
 717         }
 718
 719         /**
 720          * Shortcut to get the User executing this instance
 721          *
 722          * @return User
 723          * @since 1.18
 724          */
 725         public function getUser() {
 726                 return $this->getContext()->getUser();
 727         }
 728
 729         /**
 730          * Shortcut to get the skin being used for this instance
 731          *
 732          * @return Skin
 733          * @since 1.18
 734          */
 735         public function getSkin() {
 736                 return $this->getContext()->getSkin();
 737         }
 738
 739         /**
 740          * Shortcut to get user's language
 741          *
 742          * @return Language
 743          * @since 1.19
 744          */
 745         public function getLanguage() {
 746                 return $this->getContext()->getLanguage();
 747         }
 748
 749         /**
 750          * Shortcut to get main config object
 751          * @return Config
 752          * @since 1.24
 753          */
 754         public function getConfig() {
 755                 return $this->getContext()->getConfig();
 756         }
 757
 758         /**
 759          * Return the full title, including $par
 760          *
 761          * @return Title
 762          * @since 1.18
 763          */
 764         public function getFullTitle() {
 765                 return $this->getContext()->getTitle();
 766         }
 767
 768         /**
 769          * Return the robot policy. Derived classes that override this can change
 770          * the robot policy set by setHeaders() from the default 'noindex,nofollow'.
 771          *
 772          * @return string
 773          * @since 1.23
 774          */
 775         protected function getRobotPolicy() {
 776                 return 'noindex,nofollow';
 777         }
 778
 779         /**
 780          * Wrapper around wfMessage that sets the current context.
 781          *
 782          * @since 1.16
 783          * @return Message
 784          * @see wfMessage
 785          */
 786         public function msg( $key /* $args */ ) {
 787                 $message = $this->getContext()->msg( ...func_get_args() );
 788                 // RequestContext passes context to wfMessage, and the language is set from
 789                 // the context, but setting the language for Message class removes the
 790                 // interface message status, which breaks for example usernameless gender
 791                 // invocations. Restore the flag when not including special page in content.
 792                 if ( $this->including() ) {
 793                         $message->setInterfaceMessageFlag( false );
 794                 }
 795
 796                 return $message;
 797         }
 798
 799         /**
 800          * Adds RSS/atom links
 801          *
 802          * @param array $params
 803          */
 804         protected function addFeedLinks( $params ) {
 805                 $feedTemplate = wfScript( 'api' );
 806
 807                 foreach ( $this->getConfig()->get( 'FeedClasses' ) as $format => $class ) {
 808                         $theseParams = $params + [ 'feedformat' => $format ];
 809                         $url = wfAppendQuery( $feedTemplate, $theseParams );
 810                         $this->getOutput()->addFeedLink( $format, $url );
 811                 }
 812         }
 813
 814         /**
 815          * Adds help link with an icon via page indicators.
 816          * Link target can be overridden by a local message containing a wikilink:
 817          * the message key is: lowercase special page name + '-helppage'.
 818          * @param string $to Target MediaWiki.org page title or encoded URL.
 819          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
 820          * @since 1.25
 821          */
 822         public function addHelpLink( $to, $overrideBaseUrl = false ) {
 823                 if ( $this->including() ) {
 824                         return;
 825                 }
 826
 827                 $msg = $this->msg(
 828                         MediaWikiServices::getInstance()->getContentLanguage()->lc( $this->getName() ) .
 829                         '-helppage' );
 830
 831                 if ( !$msg->isDisabled() ) {
 832                         $helpUrl = Skin::makeUrl( $msg->plain() );
 833                         $this->getOutput()->addHelpLink( $helpUrl, true );
 834                 } else {
 835                         $this->getOutput()->addHelpLink( $to, $overrideBaseUrl );
 836                 }
 837         }
 838
 839         /**
 840          * Get the group that the special page belongs in on Special:SpecialPage
 841          * Use this method, instead of getGroupName to allow customization
 842          * of the group name from the wiki side
 843          *
 844          * @return string Group of this special page
 845          * @since 1.21
 846          */
 847         public function getFinalGroupName() {
 848                 $name = $this->getName();
 849
 850                 // Allow overriding the group from the wiki side
 851                 $msg = $this->msg( 'specialpages-specialpagegroup-' . strtolower( $name ) )->inContentLanguage();
 852                 if ( !$msg->isBlank() ) {
 853                         $group = $msg->text();
 854                 } else {
 855                         // Than use the group from this object
 856                         $group = $this->getGroupName();
 857                 }
 858
 859                 return $group;
 860         }
 861
 862         /**
 863          * Indicates whether this special page may perform database writes
 864          *
 865          * @return bool
 866          * @since 1.27
 867          */
 868         public function doesWrites() {
 869                 return false;
 870         }
 871
 872         /**
 873          * Under which header this special page is listed in Special:SpecialPages
 874          * See messages 'specialpages-group-*' for valid names
 875          * This method defaults to group 'other'
 876          *
 877          * @return string
 878          * @since 1.21
 879          */
 880         protected function getGroupName() {
 881                 return 'other';
 882         }
 883
 884         /**
 885          * Call wfTransactionalTimeLimit() if this request was POSTed
 886          * @since 1.26
 887          */
 888         protected function useTransactionalTimeLimit() {
 889                 if ( $this->getRequest()->wasPosted() ) {
 890                         wfTransactionalTimeLimit();
 891                 }
 892         }
 893
 894         /**
 895          * @since 1.28
 896          * @return \MediaWiki\Linker\LinkRenderer
 897          */
 898         public function getLinkRenderer() {
 899                 if ( $this->linkRenderer ) {
 900                         return $this->linkRenderer;
 901                 } else {
 902                         return MediaWikiServices::getInstance()->getLinkRenderer();
 903                 }
 904         }
 905
 906         /**
 907          * @since 1.28
 908          * @param \MediaWiki\Linker\LinkRenderer $linkRenderer
 909          */
 910         public function setLinkRenderer( LinkRenderer $linkRenderer ) {
 911                 $this->linkRenderer = $linkRenderer;
 912         }
 913
 914         /**
 915          * Generate (prev x| next x) (20|50|100...) type links for paging
 916          *
 917          * @param int $offset
 918          * @param int $limit
 919          * @param array $query Optional URL query parameter string
 920          * @param bool $atend Optional param for specified if this is the last page
 921          * @param string|bool $subpage Optional param for specifying subpage
 922          * @return string
 923          */
 924         protected function buildPrevNextNavigation( $offset, $limit,
 925                                                                                          array $query = [], $atend = false, $subpage = false
 926         ) {
 927                 $title = $this->getPageTitle( $subpage );
 928                 $prevNext = new PrevNextNavigationRenderer( $this );
 929
 930                 return $prevNext->buildPrevNextNavigation( $title, $offset, $limit, $query,  $atend );
 931         }
 932 }