includes/specialpage/SpecialPage.php

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