Hooks can return three possible values:
- * true: the hook has operated successfully
+ * No return value (or null): the hook has operated successfully. Previously,
+ true was required. This is the default since MediaWiki 1.23.
* "some string": an error occurred; processing should stop and the error
should be shown to the user
* false: the hook has successfully done the work necessary and the calling
'APIEditBeforeSave': Before saving a page with api.php?action=edit, after
processing request parameters. Return false to let the request fail, returning
an error message or an <edit result="Failure"> tag if $resultArr was filled.
+Unlike for example 'EditFilterMergedContent' this also being run on undo.
$editPage: the EditPage object
$text: the new text of the article (has yet to be saved)
&$resultArr: data in this array will be added to the API result
$request: $wgRequest
$mediaWiki: The $mediawiki object
+'MediaWikiServices': Override services in the default MediaWikiServices instance.
+Extensions may use this to define, replace, or wrap existing services.
+However, the preferred way to define a new service is the $wgServiceWiringFiles array.
+$services: MediaWikiServices
+
'MessageCache::get': When fetching a message. Can be used to override the key
for customisations. Given and returned message key must be in special format:
1) first letter must be in lower case according to the content language.
$subPage: the subpage string or null if no subpage was specified
'SpecialPageBeforeExecute': Called before SpecialPage::execute.
+Return false to prevent execution.
$special: the SpecialPage object
$subPage: the subpage string or null if no subpage was specified
$nt: new title
$user: user who does the move
+'TitleMoveStarting': Before moving an article (title), but just after the atomic DB section starts.
+$old: old title
+$nt: new title
+$user: user who does the move
+
'TitleMoveComplete': After moving an article (title), post-commit.
&$old: old title
&$nt: new title