docs/hooks.txt

   1 hooks.txt
   2
   3 This document describes how event hooks work in MediaWiki; how to add
   4 hooks for an event; and how to run hooks for an event.
   5
   6 ==Glossary==
   7
   8 event
   9      Something that happens with the wiki. For example: a user logs
  10      in. A wiki page is saved. A wiki page is deleted. Often there are
  11      two events associated with a single action: one before the code
  12      is run to make the event happen, and one after. Each event has a
  13      name, preferably in CamelCase. For example, 'UserLogin',
  14      'ArticleSave', 'ArticleSaveComplete', 'ArticleDelete'.
  15
  16 hook
  17      A clump of code and data that should be run when an event
  18      happens. This can be either a function and a chunk of data, or an
  19      object and a method.
  20
  21 hook function
  22      The function part of a hook.
  23
  24 ==Rationale==
  25
  26 Hooks allow us to decouple optionally-run code from code that is run
  27 for everyone. It allows MediaWiki hackers, third-party developers and
  28 local administrators to define code that will be run at certain points
  29 in the mainline code, and to modify the data run by that mainline
  30 code. Hooks can keep mainline code simple, and make it easier to
  31 write extensions. Hooks are a principled alternative to local patches.
  32
  33 Consider, for example, two options in MediaWiki. One reverses the
  34 order of a title before displaying the article; the other converts the
  35 title to all uppercase letters. Currently, in MediaWiki code, we
  36 would handle this as follows (note: not real code, here):
  37
  38         function showAnArticle($article) {
  39                 global $wgReverseTitle, $wgCapitalizeTitle;
  40
  41                 if ($wgReverseTitle) {
  42                         wfReverseTitle($article);
  43                 }
  44
  45                 if ($wgCapitalizeTitle) {
  46                         wfCapitalizeTitle($article);
  47                 }
  48
  49                 # code to actually show the article goes here
  50         }
  51
  52 An extension writer, or a local admin, will often add custom code to
  53 the function -- with or without a global variable. For example,
  54 someone wanting email notification when an article is shown may add:
  55
  56     function showAnArticle($article) {
  57         global $wgReverseTitle, $wgCapitalizeTitle;
  58
  59         if ($wgReverseTitle) {
  60             wfReverseTitle($article);
  61         }
  62
  63         if ($wgCapitalizeTitle) {
  64            wfCapitalizeTitle($article);
  65         }
  66
  67         # code to actually show the article goes here
  68
  69         if ($wgNotifyArticle) {
  70            wfNotifyArticleShow($article));
  71         }
  72     }
  73
  74 Using a hook-running strategy, we can avoid having all this
  75 option-specific stuff in our mainline code. Using hooks, the function
  76 becomes:
  77
  78         function showAnArticle($article) {
  79
  80                 if (wfRunHooks('ArticleShow', array(&$article))) {
  81
  82                         # code to actually show the article goes here
  83
  84                         wfRunHooks('ArticleShowComplete', array(&$article));
  85                 }
  86         }
  87
  88 We've cleaned up the code here by removing clumps of weird,
  89 infrequently used code and moving them off somewhere else. It's much
  90 easier for someone working with this code to see what's _really_ going
  91 on, and make changes or fix bugs.
  92
  93 In addition, we can take all the code that deals with the little-used
  94 title-reversing options (say) and put it in one place. Instead of
  95 having little title-reversing if-blocks spread all over the codebase
  96 in showAnArticle, deleteAnArticle, exportArticle, etc., we can
  97 concentrate it all in an extension file:
  98
  99         function reverseArticleTitle($article) {
 100                 # ...
 101         }
 102
 103         function reverseForExport($article) {
 104                 # ...
 105         }
 106
 107 The setup function for the extension just has to add its hook
 108 functions to the appropriate events:
 109
 110         setupTitleReversingExtension() {
 111                 global $wgHooks;
 112
 113                 $wgHooks['ArticleShow'][] = 'reverseArticleTitle';
 114                 $wgHooks['ArticleDelete'][] = 'reverseArticleTitle';
 115                 $wgHooks['ArticleExport'][] = 'reverseForExport';
 116         }
 117
 118 Having all this code related to the title-reversion option in one
 119 place means that it's easier to read and understand; you don't have to
 120 do a grep-find to see where the $wgReverseTitle variable is used, say.
 121
 122 If the code is well enough isolated, it can even be excluded when not
 123 used -- making for some slight savings in memory and load-up
 124 performance at runtime. Admins who want to have all the reversed
 125 titles can add:
 126
 127         require_once('extensions/ReverseTitle.php');
 128
 129 ...to their LocalSettings.php file; those of us who don't want or need
 130 it can just leave it out.
 131
 132 The extensions don't even have to be shipped with MediaWiki; they
 133 could be provided by a third-party developer or written by the admin
 134 him/herself.
 135
 136 ==Writing hooks==
 137
 138 A hook is a chunk of code run at some particular event. It consists of:
 139
 140   * a function with some optional accompanying data, or
 141   * an object with a method and some optional accompanying data.
 142
 143 Hooks are registered by adding them to the global $wgHooks array for a
 144 given event. All the following are valid ways to define hooks:
 145
 146         $wgHooks['EventName'][] = 'someFunction'; # function, no data
 147         $wgHooks['EventName'][] = array('someFunction', $someData);
 148         $wgHooks['EventName'][] = array('someFunction'); # weird, but OK
 149
 150         $wgHooks['EventName'][] = $object; # object only
 151         $wgHooks['EventName'][] = array($object, 'someMethod');
 152         $wgHooks['EventName'][] = array($object, 'someMethod', $someData);
 153         $wgHooks['EventName'][] = array($object); # weird but OK
 154
 155 When an event occurs, the function (or object method) will be called
 156 with the optional data provided as well as event-specific parameters.
 157 The above examples would result in the following code being executed
 158 when 'EventName' happened:
 159
 160         # function, no data
 161         someFunction($param1, $param2)
 162         # function with data
 163         someFunction($someData, $param1, $param2)
 164
 165         # object only
 166         $object->onEventName($param1, $param2)
 167         # object with method
 168         $object->someMethod($param1, $param2)
 169         # object with method and data
 170         $object->someMethod($someData, $param1, $param2)
 171
 172 Note that when an object is the hook, and there's no specified method,
 173 the default method called is 'onEventName'. For different events this
 174 would be different: 'onArticleSave', 'onUserLogin', etc.
 175
 176 The extra data is useful if we want to use the same function or object
 177 for different purposes. For example:
 178
 179         $wgHooks['ArticleSaveComplete'][] = array('ircNotify', 'TimStarling');
 180         $wgHooks['ArticleSaveComplete'][] = array('ircNotify', 'brion');
 181
 182 This code would result in ircNotify being run twice when an article is
 183 saved: once for 'TimStarling', and once for 'brion'.
 184
 185 Hooks can return three possible values:
 186
 187   * true: the hook has operated successfully
 188   * "some string": an error occurred; processing should
 189           stop and the error should be shown to the user
 190   * false: the hook has successfully done the work
 191            necessary and the calling function should skip
 192
 193 The last result would be for cases where the hook function replaces
 194 the main functionality. For example, if you wanted to authenticate
 195 users to a custom system (LDAP, another PHP program, whatever), you
 196 could do:
 197
 198         $wgHooks['UserLogin'][] = array('ldapLogin', $ldapServer);
 199
 200         function ldapLogin($username, $password) {
 201                 # log user into LDAP
 202                 return false;
 203         }
 204
 205 Returning false makes less sense for events where the action is
 206 complete, and will normally be ignored.
 207
 208 ==Using hooks==
 209
 210 A calling function or method uses the wfRunHooks() function to run
 211 the hooks related to a particular event, like so:
 212
 213         class Article {
 214                 # ...
 215                 function protect() {
 216                         global $wgUser;
 217                         if (wfRunHooks('ArticleProtect', array(&$this, &$wgUser))) {
 218                                 # protect the article
 219                                 wfRunHooks('ArticleProtectComplete', array(&$this, &$wgUser));
 220                         }
 221                 }
 222         }
 223
 224 wfRunHooks() returns true if the calling function should continue
 225 processing (the hooks ran OK, or there are no hooks to run), or false
 226 if it shouldn't (an error occurred, or one of the hooks handled the
 227 action already). Checking the return value matters more for "before"
 228 hooks than for "complete" hooks.
 229
 230 Note that hook parameters are passed in an array; this is a necessary
 231 inconvenience to make it possible to pass reference values (that can
 232 be changed) into the hook code. Also note that earlier versions of
 233 wfRunHooks took a variable number of arguments; the array() calling
 234 protocol came about after MediaWiki 1.4rc1.
 235
 236 ==Events and parameters==
 237
 238 This is a list of known events and parameters; please add to it if
 239 you're going to add events to the MediaWiki code.
 240
 241 'AbortLogin': Return false to cancel account login.
 242 $user: the User object being authenticated against
 243 $password: the password being submitted, not yet checked for validity
 244 &$retval: a LoginForm class constant to return from authenticateUserData();
 245           default is LoginForm::ABORTED. Note that the client may be using
 246           a machine API rather than the HTML user interface.
 247
 248 'AbortMove': allows to abort moving an article (title)
 249 $old: old title
 250 $nt: new title
 251 $user: user who is doing the move
 252 $err: error message
 253
 254 'AbortNewAccount': Return false to cancel account creation.
 255 $user: the User object about to be created (read-only, incomplete)
 256 $message: out parameter: error message to display on abort
 257
 258 'AddNewAccount': after a user account is created
 259 $user: the User object that was created. (Parameter added in 1.7)
 260
 261 'AjaxAddScript': Called in output page just before the initialisation
 262 of the javascript ajax engine. The hook is only called when ajax
 263 is enabled ( $wgUseAjax = true; ).
 264
 265 'AlternateEdit': before checking if an user can edit a page and
 266 before showing the edit form ( EditPage::edit() ). This is triggered
 267 on &action=edit.
 268 $EditPage : the EditPage object
 269
 270 'ArticleAfterFetchContent': after fetching content of an article from the database
 271 $article: the article (object) being loaded from the database
 272 $content: the content (string) of the article
 273
 274 'ArticleDelete': before an article is deleted
 275 $article: the article (object) being deleted
 276 $user: the user (object) deleting the article
 277 $reason: the reason (string) the article is being deleted
 278
 279 'ArticleDeleteComplete': after an article is deleted
 280 $article: the article that was deleted
 281 $user: the user that deleted the article
 282 $reason: the reason the article was deleted
 283
 284 'ArticleEditUpdateNewTalk': before updating user_newtalk when a user talk page was changed
 285 $article: article (object) of the user talk page
 286
 287 'ArticleEditUpdatesDeleteFromRecentchanges': before deleting old entries from recentchanges table, return false to not delete old entries
 288 $article: article (object) being modified
 289
 290 'ArticleFromTitle': when creating an article object from a title object using Wiki::articleFromTitle()
 291 $title: title (object) used to create the article object
 292 $article: article (object) that will be returned
 293
 294 'ArticleInsertComplete': After an article is created
 295 $article: Article created
 296 $user: User creating the article
 297 $text: New content
 298 $summary: Edit summary/comment
 299 $isMinor: Whether or not the edit was marked as minor
 300 $isWatch: (No longer used)
 301 $section: (No longer used)
 302 $flags: Flags passed to Article::doEdit()
 303 $revision: New Revision of the article
 304
 305 'ArticleMergeComplete': after merging to article using Special:Mergehistory
 306 $targetTitle: target title (object)
 307 $destTitle: destination title (object)
 308
 309 'ArticlePageDataAfter': after loading data of an article from the database
 310 $article: article (object) whose data were loaded
 311 $row: row (object) returned from the database server
 312
 313 'ArticlePageDataBefore': before loading data of an article from the database
 314 $article: article (object) that data will be loaded
 315 $fields: fileds (array) to load from the database
 316
 317 'ArticleProtect': before an article is protected
 318 $article: the article being protected
 319 $user: the user doing the protection
 320 $protect: boolean whether this is a protect or an unprotect
 321 $reason: Reason for protect
 322 $moveonly: boolean whether this is for move only or not
 323
 324 'ArticleProtectComplete': after an article is protected
 325 $article: the article that was protected
 326 $user: the user who did the protection
 327 $protect: boolean whether it was a protect or an unprotect
 328 $reason: Reason for protect
 329 $moveonly: boolean whether it was for move only or not
 330
 331 'ArticlePurge': before executing "&action=purge"
 332 $article: article (object) to purge
 333
 334 'ArticleRevisionUndeleted' after an article revision is restored
 335 $title: the article title
 336 $revision: the revision
 337 $oldPageID: the page ID of the revision when archived (may be null)
 338
 339 'ArticleRollbackComplete': after an article rollback is completed
 340 $article: the article that was edited
 341 $user: the user who did the rollback
 342 $revision: the revision the page was reverted back to
 343
 344 'ArticleSave': before an article is saved
 345 $article: the article (object) being saved
 346 $user: the user (object) saving the article
 347 $text: the new article text
 348 $summary: the article summary (comment)
 349 $isminor: minor flag
 350 $iswatch: watch flag
 351 $section: section #
 352
 353 'ArticleSaveComplete': After an article has been updated
 354 $article: Article modified
 355 $user: User performing the modification
 356 $text: New content
 357 $summary: Edit summary/comment
 358 $isMinor: Whether or not the edit was marked as minor
 359 $isWatch: (No longer used)
 360 $section: (No longer used)
 361 $flags: Flags passed to Article::doEdit()
 362 $revision: New Revision of the article
 363
 364 'ArticleSaveComplete': after an article is saved
 365 $article: the article (object) saved
 366 $user: the user (object) who saved the article
 367 $text: the new article text
 368 $summary: the article summary (comment)
 369 $isminor: minor flag
 370 $iswatch: watch flag
 371 $section: section #
 372
 373 wfRunHooks( 'ArticleSaveComplete', array( &$this, &$wgUser, $text, $summary, $flags & EDIT_MINOR, null, null, &$flags, $revision ) );
 374
 375 'ArticleUndelete': When one or more revisions of an article are restored
 376 $title: Title corresponding to the article restored
 377 $create: Whether or not the restoration caused the page to be created
 378 (i.e. it didn't exist before)
 379
 380 'ArticleUpdateBeforeRedirect': After a page is updated (usually on save), before the user is redirected back to the page
 381 &$article: the article
 382 &$sectionanchor: The section anchor link (e.g. "#overview" )
 383 &$extraq: Extra query parameters which can be added via hooked functions
 384
 385 'ArticleViewHeader': Before the parser cache is about to be tried for article viewing.
 386 &$article: the article
 387 &$pcache: whether to try the parser cache or not
 388 &$outputDone: whether the output for this page finished or not
 389
 390 'ArticleViewRedirect': before setting "Redirected from ..." subtitle when follwed an redirect
 391 $article: target article (object)
 392
 393 'AuthPluginSetup': update or replace authentication plugin object ($wgAuth)
 394 Gives a chance for an extension to set it programattically to a variable class.
 395 &$auth: the $wgAuth object, probably a stub
 396
 397 'AutoAuthenticate': called to authenticate users on external/environmental means
 398 $user: writes user object to this parameter
 399
 400 'AutopromoteCondition': check autopromote condition for user.
 401 $type: condition type
 402 $args: arguments
 403 $user: user
 404 $result: result of checking autopromote condition
 405
 406 'BadImage': When checking against the bad image list
 407 $name: Image name being checked
 408 &$bad: Whether or not the image is "bad"
 409
 410 Change $bad and return false to override. If an image is "bad", it is not
 411 rendered inline in wiki pages or galleries in category pages.
 412
 413 'BeforeGalleryFindFile': before an image is fetched for a gallery
 414 &$gallery,: the gallery object
 415 &$nt: the image title
 416 &$time: image timestamp
 417
 418 'BeforePageDisplay': Prior to outputting a page
 419 $out: OutputPage object
 420
 421 'BeforeParserFetchTemplateAndtitle': before a template is fetched by Parser
 422 &$parser: Parser object
 423 &$title: title of the template
 424 &$skip: skip this template and link it?
 425 &$id: the id of the revision being parsed
 426
 427 'BeforeParserMakeImageLinkObj': before an image is rendered by Parser
 428 &$parser: Parser object
 429 &$nt: the image title
 430 &$skip: skip this image and link it?
 431 &$time: the image timestamp
 432
 433 'BeforeParserrenderImageGallery': before an image gallery is rendered by Parser
 434 &$parser: Parser object
 435 &$ig: ImageGallery object
 436
 437 'BeforeWatchlist': Override watchlist display or add extra SQL clauses.
 438 $nondefaults: Assoc array with the following keys:
 439               days, hideOwn, hideBots, hideMinor, namespace
 440 $wgUser: wgUser.
 441 &$hookSql: a string which will be inserted without sanitation into the SQL query
 442            used to get the watchlist, at the end of the WHERE part.
 443
 444 'BlockIp': before an IP address or user is blocked
 445 $block: the Block object about to be saved
 446 $user: the user _doing_ the block (not the one being blocked)
 447
 448 'BlockIpComplete': after an IP address or user is blocked
 449 $block: the Block object that was saved
 450 $user: the user who did the block (not the one being blocked)
 451
 452 'BookInformation': Before information output on Special:Booksources
 453 $isbn: ISBN to show information for
 454 $output: OutputPage object in use
 455
 456 'CategoryPageView': before viewing a categorypage in CategoryPage::view
 457 $catpage: CategoryPage instance
 458
 459 'ChangesListInsertArticleLink': Override or augment link to article in RC list.
 460 &$this:        ChangesList instance.
 461 &$articlelink: HTML of link to article (already filled-in).
 462 &$s:           HTML of row that is being constructed.
 463 &$rc:          RecentChange instance.
 464 $unpatrolled:  Whether or not we are showing unpatrolled changes.
 465 $watched:      Whether or not the change is watched by the user.
 466
 467 'ContributionsToolLinks': Change tool links above Special:Contributions
 468 $id: User identifier
 469 $title: User page title
 470 &$tools: Array of tool links
 471
 472 'CustomEditor': When invoking the page editor
 473 $article: Article being edited
 474 $user: User performing the edit
 475
 476 Return true to allow the normal editor to be used, or false
 477 if implementing a custom editor, e.g. for a special namespace,
 478 etc.
 479
 480 'DiffViewHeader': called before diff display
 481 $diff: DifferenceEngine object that's calling
 482 $oldRev: Revision object of the "old" revision (may be null/invalid)
 483 $newRev: Revision object of the "new" revision
 484
 485 'DisplayOldSubtitle': before creating subtitle when browsing old versions of an article
 486 $article: article (object) being viewed
 487 $oldid: oldid (int) being viewed
 488
 489 'EditFilter': Perform checks on an edit
 490 $editor: Edit form (see includes/EditPage.php)
 491 $text: Contents of the edit box
 492 $section: Section being edited
 493 &$error: Error message to return
 494
 495 'EditFilterMerged': Post-section-merge edit filter
 496 $editor: EditPage instance (object)
 497 $text: content of the edit box
 498 $error: error message to return
 499
 500 'EditFormPreloadText': Allows population of the edit form when creating new pages
 501 &$text: Text to preload with
 502 &$title: Title object representing the page being created
 503
 504 'EditPage::attemptSave': called before an article is
 505 saved, that is before insertNewArticle() is called
 506 &$editpage_Obj: the current EditPage object
 507
 508 'EditPage::showEditForm:fields': allows injection of form field into edit form
 509 &$editor: the EditPage instance for reference
 510 &$out: an OutputPage instance to write to
 511 return value is ignored (should always return true)
 512
 513 'EditPage::showEditForm:initial': before showing the edit form
 514 $editor: EditPage instance (object)
 515
 516 Return false to halt editing; you'll need to handle error messages, etc. yourself.
 517 Alternatively, modifying $error and returning true will cause the contents of $error
 518 to be echoed at the top of the edit form as wikitext. Return true without altering
 519 $error to allow the edit to proceed.
 520
 521 'EditSectionLink': Override the return value of Linker::editSectionLink()
 522 $skin: Skin rendering the UI
 523 $title: Title being linked to
 524 $section: Section to link to
 525 $link: Default link
 526 $result: Result (alter this to override the generated links)
 527
 528 'EditSectionLinkForOther': Override the return value of Linker::editSectionLinkForOther()
 529 $skin: Skin rendering the UI
 530 $title: Title being linked to
 531 $section: Section to link to
 532 $hint: Anchor title/tooltip attributes
 533 $link: Default link
 534 $result: Result (alter this to override the generated links)
 535
 536 'EmailConfirmed': When checking that the user's email address is "confirmed"
 537 $user: User being checked
 538 $confirmed: Whether or not the email address is confirmed
 539 This runs before the other checks, such as anonymity and the real check; return
 540 true to allow those checks to occur, and false if checking is done.
 541
 542 'EmailUser': before sending email from one user to another
 543 $to: address of receiving user
 544 $from: address of sending user
 545 $subject: subject of the mail
 546 $text: text of the mail
 547
 548 'EmailUserComplete': after sending email from one user to another
 549 $to: address of receiving user
 550 $from: address of sending user
 551 $subject: subject of the mail
 552 $text: text of the mail
 553
 554 'FetchChangesList': When fetching the ChangesList derivative for a particular user
 555 &$user: User the list is being fetched for
 556 &$skin: Skin object to be used with the list
 557 &$list: List object (defaults to NULL, change it to an object instance and return
 558 false override the list derivative used)
 559
 560 'FileUpload': When a file upload occurs
 561 $file : Image object representing the file that was uploaded
 562
 563 'GetBlockedStatus': after loading blocking status of an user from the database
 564 $user: user (object) being checked
 565
 566 'GetFullURL': modify fully-qualified URLs used in redirects/export/offsite data
 567 $title: Title object of page
 568 $url: string value as output (out parameter, can modify)
 569 $query: query options passed to Title::getFullURL()
 570
 571 'GetInternalURL': modify fully-qualified URLs used for squid cache purging
 572 $title: Title object of page
 573 $url: string value as output (out parameter, can modify)
 574 $query: query options passed to Title::getInternalURL()
 575
 576 'GetLinkColours': modify the CSS class of an array of page links
 577 $linkcolour_ids: array of prefixed DB keys of the pages linked to, indexed by page_id.
 578 &$colours: (output) array of CSS classes, indexed by prefixed DB keys
 579
 580 'GetLocalURL': modify local URLs as output into page links
 581 $title: Title object of page
 582 $url: string value as output (out parameter, can modify)
 583 $query: query options passed to Title::getLocalURL()
 584
 585 'getUserPermissionsErrors': Add a permissions error when permissions errors are
 586         checked for.  Use instead of userCan for most cases. Return false if the
 587         user can't do it, and populate $result with the reason in the form of
 588         array( messagename, param1, param2, ... ).  For consistency, error messages
 589         should be plain text with no special coloring, bolding, etc. to show that
 590         they're errors; presenting them properly to the user as errors is done by
 591         the caller.
 592 $title: Title object being checked against
 593 $user : Current user object
 594 $action: Action being checked
 595 $result: User permissions error to add. If none, return true.
 596
 597 'ImageOpenShowImageInlineBefore': Call potential extension just before showing the image on an image page
 598 $imagePage: ImagePage object ($this)
 599 $output: $wgOut
 600
 601 'InitPreferencesForm': called at the end of PreferencesForm's constructor
 602 $form: the PreferencesForm
 603 $request: the web request to initialized from
 604
 605 'InternalParseBeforeLinks': during Parser's internalParse method before links but
 606 after noinclude/includeonly/onlyinclude and other processing.
 607 &$this: Parser object
 608 &$text: string containing partially parsed text
 609 &$this->mStripState: Parser's internal StripState object
 610
 611 'IsFileCacheable': Override the result of Article::isFileCacheable() (if true)
 612 $article: article (object) being checked
 613
 614 'IsTrustedProxy': Override the result of wfIsTrustedProxy()
 615 $ip: IP being check
 616 $result: Change this value to override the result of wfIsTrustedProxy()
 617
 618 'isValidEmailAddr': Override the result of User::isValidEmailAddr(), for ins-
 619 tance to return false if the domain name doesn't match your organization
 620 $addr: The e-mail address entered by the user
 621 &$result: Set this and return false to override the internal checks
 622
 623 'isValidPassword': Override the result of User::isValidPassword()
 624 $password: The password entered by the user
 625 &$result: Set this and return false to override the internal checks
 626 $user: User the password is being validated for
 627
 628 'LanguageGetMagic': Use this to define synonyms of magic words depending of the language
 629 $magicExtensions: associative array of magic words synonyms
 630 $lang: laguage code (string)
 631
 632 'LanguageGetSpecialPageAliases': Use to define aliases of special pages names depending of the language
 633 $specialPageAliases: associative array of magic words synonyms
 634 $lang: laguage code (string)
 635
 636 'LinksUpdateConstructed': At the end of LinksUpdate() is contruction.
 637 &$linksUpdate: the LinkUpdate object
 638
 639 'LoadAllMessages': called by MessageCache::loadAllMessages() to load extensions messages
 640
 641 'LoadExtensionSchemaUpdates': called by maintenance/updaters.inc when upgrading database schema
 642
 643 'LoginAuthenticateAudit': a login attempt for a valid user account either succeeded or failed.
 644                           No return data is accepted; this hook is for auditing only.
 645 $user: the User object being authenticated against
 646 $password: the password being submitted and found wanting
 647 $retval: a LoginForm class constant with authenticateUserData() return value (SUCCESS, WRONG_PASS, etc)
 648
 649 'LogLine': Processes a single log entry on Special:Log
 650 $log_type: string for the type of log entry (e.g. 'move'). Corresponds to logging.log_type
 651     database field.
 652 $log_action: string for the type of log action (e.g. 'delete', 'block', 'create2'). Corresponds
 653     to logging.log_action database field.
 654 $title: Title object that corresponds to logging.log_namespace and logging.log_title database fields.
 655 $paramArray: Array of parameters that corresponds to logging.log_params field. Note that only $paramArray[0]
 656     appears to contain anything.
 657 &$comment: string that corresponds to logging.log_comment database field, and which is displayed in the UI.
 658 &$revert: string that is displayed in the UI, similar to $comment.
 659
 660 'LogPageValidTypes': action being logged. DEPRECATED: Use $wgLogTypes
 661 &$type: array of strings
 662
 663 'LogPageLogName': name of the logging page(s). DEPRECATED: Use $wgLogNames
 664 &$typeText: array of strings
 665
 666 'LogPageLogHeader': strings used by wfMsg as a header. DEPRECATED: Use $wgLogHeaders
 667 &$headerText: array of strings
 668
 669 'LogPageActionText': strings used by wfMsg as a header. DEPRECATED: Use $wgLogActions
 670 &$actionText: array of strings
 671
 672 'MagicWordMagicWords': When defining new magic word. DEPRECATED: Use LanguageGetMagic hook instead
 673 $magicWords: array of strings
 674
 675 'MagicWordwgVariableIDs': When definig new magic words IDs. DEPRECATED: Use LanguageGetMagic hook instead
 676 $variableIDs: array of strings
 677
 678 'MarkPatrolled': before an edit is marked patrolled
 679 $rcid: ID of the revision to be marked patrolled
 680 $user: the user (object) marking the revision as patrolled
 681 $wcOnlySysopsCanPatrol: config setting indicating whether the user
 682  needs to be a sysop in order to mark an edit patrolled
 683
 684 'MarkPatrolledComplete': after an edit is marked patrolled
 685 $rcid: ID of the revision marked as patrolled
 686 $user: user (object) who marked the edit patrolled
 687 $wcOnlySysopsCanPatrol: config setting indicating whether the user
 688  must be a sysop to patrol the edit
 689
 690 'MathAfterTexvc': after texvc is executed when rendering mathematics
 691 $mathRenderer: instance of MathRenderer
 692 $errmsg: error message, in HTML (string). Nonempty indicates failure
 693  of rendering the formula
 694
 695 'MediaWikiPerformAction': Override MediaWiki::performAction().
 696 Use this to do something completely different, after the basic
 697 globals have been set up, but before ordinary actions take place.
 698 $output:  $wgOut
 699 $article: $wgArticle
 700 $title:   $wgTitle
 701 $user:    $wgUser
 702 $request: $wgRequest
 703
 704 'MessagesPreLoad': When loading a message from the database
 705 $title: title of the message (string)
 706 $message: value (string), change it to the message you want to define
 707
 708 'MonoBookTemplateToolboxEnd': Called by Monobook skin after toolbox links have been rendered (useful for adding more)
 709 $tools: array of tools
 710
 711 'OutputPageBeforeHTML': a page has been processed by the parser and
 712 the resulting HTML is about to be displayed.
 713 $parserOutput: the parserOutput (object) that corresponds to the page
 714 $text: the text that will be displayed, in HTML (string)
 715
 716 'OutputPageParserOutput': after adding a parserOutput to $wgOut
 717 $out: OutputPage instance (object)
 718 $parserOutput: parserOutput instance being added in $out
 719
 720 'PageHistoryBeforeList': When a history page list is about to be constructed.
 721 $article: the article that the history is loading for
 722
 723 'PageHistoryLineEnding' : right before the end <li> is added to a history line
 724 $row: the revision row for this line
 725 $s: the string representing this parsed line
 726
 727 'PageRenderingHash': alter the parser cache option hash key
 728   A parser extension which depends on user options should install
 729   this hook and append its values to the key.
 730 $hash: reference to a hash key string which can be modified
 731
 732 'ParserAfterStrip': Same as ParserBeforeStrip
 733
 734 'ParserAfterTidy': Called after Parser::tidy() in Parser::parse()
 735 $parser: Parser object being used
 736 $text: text that'll be returned
 737
 738 'ParserBeforeInternalParse': called at the beginning of Parser::internalParse()
 739 $parser: Parser object
 740 $text: text to parse
 741 $stripState: StripState instance being used
 742
 743 'ParserBeforeStrip': Called at start of parsing time (no more strip, deprecated ?)
 744 $parser: parser object
 745 $text: text being parsed
 746 $stripState: stripState used (object)
 747
 748 'ParserBeforeTidy': called before tidy and custom tags replacements
 749 $parser: Parser object being used
 750 $text: actual text
 751
 752 'ParserClearState': called at the end of Parser::clearState()
 753 $parser: Parser object being cleared
 754
 755 'ParserGetVariableValueSwitch': called when the parser need the value of a custom magic word
 756 $parser: Parser object
 757 $varCache: array to store the value in case of multiples calls of the same magic word
 758 $index: index (string) of the magic
 759 $ret: value of the magic word (the hook should set it)
 760
 761 'ParserGetVariableValueTs': use this to change the value of the time for the {{LOCAL...}} magic word
 762 $parser: Parser object
 763 $time: actual time (timestamp)
 764
 765 'ParserGetVariableValueVarCache': use this to change the value of the variable cache or return false to not use it
 766 $parser: Parser object
 767 $varCache: varaiable cache (array)
 768
 769 'ParserLimitReport': called at the end of Parser:parse() when the parser will include comments about size of the text parsed
 770 $parser: Parser object
 771 $limitReport: text that will be included (without comment tags)
 772
 773 'ParserTestParser': called when creating a new instance of Parser in maintenance/parserTests.inc
 774 $parser: Parser object created
 775
 776 'ParserTestTables': alter the list of tables to duplicate when parser tests
 777 are run. Use when page save hooks require the presence of custom tables
 778 to ensure that tests continue to run properly.
 779 &$tables: array of table names
 780
 781 'PersonalUrls': Alter the user-specific navigation links (e.g. "my page,
 782 my talk page, my contributions" etc).
 783
 784 &$personal_urls: Array of link specifiers (see SkinTemplate.php)
 785 &$title: Title object representing the current page
 786
 787 'PingLimiter': Allows extensions to override the results of User::pingLimiter()
 788 &$user : User performing the action
 789 $action : Action being performed
 790 &$result : Whether or not the action should be prevented
 791 Change $result and return false to give a definitive answer, otherwise
 792 the built-in rate limiting checks are used, if enabled.
 793
 794 'PreferencesUserInformationPanel': Add HTML bits to user information list in preferences form
 795 $form : PreferencesForm object
 796 &$html : HTML to append to
 797
 798 'PrefsEmailAudit': called when user changes his email address
 799 $user: User (object) changing his email address
 800 $oldaddr: old email address (string)
 801 $newaddr: new email address (string)
 802
 803 'PrefsPasswordAudit': called when user changes his password
 804 $user: User (object) changing his passoword
 805 $newPass: new password
 806 $error: error (string) 'badretype', 'wrongpassword', 'error' or 'success'
 807
 808 'RawPageViewBeforeOutput': Right before the text is blown out in action=raw
 809 &$obj: RawPage object
 810 &$text: The text that's going to be the output
 811
 812 'RecentChange_save': called at the end of RecenChange::save()
 813 $recentChange: RecentChange object
 814
 815 'RenderPreferencesForm': called at the end of PreferencesForm::mainPrefsForm
 816 $form: the PreferencesForm
 817 $out: output page to render to, probably $wgOut
 818
 819 'ResetPreferences': called at the end of PreferencesForm::resetPrefs
 820 $form: the PreferencesForm
 821 $user: the User object to load preferences from
 822
 823 'SavePreferences': called at the end of PreferencesForm::savePreferences;
 824                    returning false prevents the preferences from being saved.
 825 $form: the PreferencesForm
 826 $user: the User object to save preferences to
 827 $message: change this to set an error message (ignored if the hook does notreturn fals)
 828
 829 'SearchUpdate': Prior to search update completion
 830 $id : Page id
 831 $namespace : Page namespace
 832 $title : Page title
 833 $text : Current text being indexed
 834
 835 'ShowRawCssJs': Customise the output of raw CSS and JavaScript in page views
 836 $text: Text being shown
 837 $title: Title of the custom script/stylesheet page
 838 $output: Current OutputPage object
 839
 840 'SiteNoticeBefore': Before the sitenotice/anonnotice is composed
 841 &$siteNotice: HTML returned as the sitenotice
 842 Return true to allow the normal method of notice selection/rendering to work,
 843 or change the value of $siteNotice and return false to alter it.
 844
 845 'SiteNoticeAfter': After the sitenotice/anonnotice is composed
 846 &$siteNotice: HTML sitenotice
 847 Alter the contents of $siteNotice to add to/alter the sitenotice/anonnotice.
 848
 849 'SkinAfterBottomScripts': At the end of Skin::bottomScripts()
 850 $skin: Skin object
 851 &$text: bottomScripts Text
 852 Append to $text to add additional text/scripts after the stock bottom scripts.
 853
 854 'SkinTemplateBuildContentActionUrlsAfterSpecialPage': after the single tab  when showing a special page
 855 $sktemplate: SkinTemplate object
 856 $content_actions: array of tabs
 857
 858 'SkinTemplateBuildNavUrlsNav_urlsAfterPermalink': after creating the "permanent link" tab
 859 $sktemplate: SkinTemplate object
 860 $nav_urls: array of tabs
 861
 862 'SkinTemplateContentActions': Alter the "content action" links in SkinTemplates
 863 &$content_actions: Content actions
 864 [See http://svn.wikimedia.org/viewvc/mediawiki/trunk/extensions/examples/Content_action.php
 865 for an example]
 866
 867 'SkinTemplateOutputPageBeforeExec': Before SkinTemplate::outputPage() starts page output
 868 &$sktemplate: SkinTemplate object
 869 &$tpl: Template engine object
 870
 871 'SkinTemplatePreventOtherActiveTabs': use this to prevent showing active tabs
 872 $sktemplate: SkinTemplate object
 873 $res: set to true to prevent active tabs
 874
 875 'SkinTemplateSetupPageCss': use this to provide per-page CSS
 876 $out: Css to return
 877
 878 'SkinTemplateTabAction': Override SkinTemplate::tabAction().
 879        You can either create your own array, or alter the parameters for the normal one.
 880 &$this:     The SkinTemplate instance.
 881 $title:     Title instance for the page.
 882 $message:   Visible label of tab.
 883 $selected:  Whether this is a selected tab.
 884 $checkEdit: Whether or not the action=edit query should be added if appropriate.
 885 &$classes:  Array of CSS classes to apply.
 886 &$query:    Query string to add to link.
 887 &$text:     Link text.
 888 &$result:   Complete assoc. array if you want to return true.
 889
 890 'SkinTemplateTabs': called when finished to build the actions tabs
 891 $sktemplate: SkinTemplate object
 892 $content_actions: array of tabs
 893
 894 'SpecialContributionsBeforeMainOutput': Before the form on Special:Contributions
 895 $id: User identifier
 896
 897 'SpecialMovepageAfterMove': called after moving a page
 898 $movePage: MovePageForm object
 899 $oldTitle: old title (object)
 900 $newTitle: new title (object)
 901
 902 'SpecialPageExecuteAfterPage': called after executing a special page
 903 Warning: Not all the special pages call this hook
 904 $specialPage: SpecialPage object
 905 $par: paramter passed to the special page (string)
 906 $funct: function called to execute the special page
 907
 908 'SpecialPageExecuteBeforeHeader': called before setting the header text of the special page
 909 Warning: Not all the special pages call this hook
 910 $specialPage: SpecialPage object
 911 $par: paramter passed to the special page (string)
 912 $funct: function called to execute the special page
 913
 914 'SpecialPageExecuteBeforePage': called after setting the special page header text but before the main execution
 915 Warning: Not all the special pages call this hook
 916 $specialPage: SpecialPage object
 917 $par: paramter passed to the special page (string)
 918 $funct: function called to execute the special page
 919
 920 'SpecialPage_initList': called when setting up SpecialPage::$mList, use this hook to remove a core special page
 921 $list: list (array) of core special pages
 922
 923 'SpecialSearchNogomatch': called when user clicked the "Go" button but the target doesn't exist
 924 $title: title object generated from the text entred by the user
 925
 926 'SpecialVersionExtensionTypes': called when generating the extensions credits, use this to change the tables headers
 927 $extTypes: associative array of extensions types
 928
 929 'TitleMoveComplete': after moving an article (title)
 930 $old: old title
 931 $nt: new title
 932 $user: user who did the move
 933 $pageid: database ID of the page that's been moved
 934 $redirid: database ID of the created redirect
 935
 936 'UndeleteShowRevision': called when showing a revision in Special:Undelete
 937 $title: title object related to the revision
 938 $rev: revision (object) that will be viewed
 939
 940 'UnknownAction': An unknown "action" has occured (useful for defining
 941                  your own actions)
 942 $action: action name
 943 $article: article "acted on"
 944
 945 'UnwatchArticle': before a watch is removed from an article
 946 $user: user watching
 947 $article: article object to be removed
 948
 949 'UnwatchArticle': after a watch is removed from an article
 950 $user: user that was watching
 951 $article: article object removed
 952
 953 'UnwatchArticleComplete': after a watch is removed from an article
 954 $user: user that watched
 955 $article: article object that was watched
 956
 957 'UploadForm:initial': before the upload form is generated
 958 $form: UploadForm object
 959 You might set the member-variables $uploadFormTextTop and
 960 $uploadFormTextAfterSummary to inject text (HTML) either before
 961 or after the editform.
 962
 963 'UploadForm:BeforeProcessing': at the beginning of processUpload()
 964 $form: UploadForm object
 965 Lets you poke at member variables like $mUploadDescription before the
 966 file is saved.
 967
 968 'UploadVerification': additional chances to reject an uploaded file
 969 string $saveName: destination file name
 970 string $tempName: filesystem path to the temporary file for checks
 971 string &$error: output: HTML error to show if upload canceled by returning false
 972
 973 'UploadComplete': Upon completion of a file upload
 974 $image: Image object representing the file that was uploaded
 975
 976 'userCan': To interrupt/advise the "user can do X to Y article" check.
 977         If you want to display an error message, try getUserPermissionsErrors.
 978 $title: Title object being checked against
 979 $user : Current user object
 980 $action: Action being checked
 981 $result: Pointer to result returned if hook returns false. If null is returned,
 982  userCan checks are continued by internal code.
 983
 984 'UserClearNewTalkNotification': called when clearing the "You have new messages!" message, return false to not delete it
 985 $user: User (object) that'll clear the message
 986
 987 'UserCreateForm': change to manipulate the login form
 988 $template: SimpleTemplate instance for the form
 989
 990 'UserEffectiveGroups': Called in User::getEffectiveGroups()
 991 $user: User to get groups for
 992 &$groups: Current effective groups
 993
 994 'UserLoginComplete': after a user has logged in
 995 $user: the user object that was created on login
 996
 997 'UserLoginForm': change to manipulate the login form
 998 $template: SimpleTemplate instance for the form
 999
1000 'UserLogout': before a user logs out
1001 $user: the user object that is about to be logged out
1002
1003 'UserLogoutComplete': after a user has logged out
1004 $user: the user object _after_ logout (won't have name, ID, etc.)
1005
1006 'UserRights': After a user's group memberships are changed
1007 $user  : User object that was changed
1008 $add   : Array of strings corresponding to groups added
1009 $remove: Array of strings corresponding to groups removed
1010
1011 'UserGetImplicitGroups': Called in User::getImplicitGroups()
1012 &$groups: List of implicit (automatically-assigned) groups
1013
1014 'UserGetRights': Called in User::getRights()
1015 $user: User to get rights for
1016 &$rights: Current rights
1017
1018 'UserRetrieveNewTalks': called when retrieving "You have new messages!" message(s)
1019 $user: user retrieving new talks messages
1020 $talks: array of new talks page(s)
1021
1022 'UserToggles': called when initialising User::$mToggles, use this to add new toggles
1023 $toggles: array of toggles to add
1024
1025 'WatchArticle': before a watch is added to an article
1026 $user: user that will watch
1027 $article: article object to be watched
1028
1029 'WatchArticleComplete': after a watch is added to an article
1030 $user: user that watched
1031 $article: article object watched
1032
1033 'wgQueryPages': called when initialising $wgQueryPages, use this to add new query pages to be updated with maintenance/updateSpecialPages.php
1034 $query: $wgQueryPages itself
1035
1036 More hooks might be available but undocumented, you can execute
1037 ./maintenance/findhooks.php to find hidden one.