Manual:Hooks/PageContentSave

Details

 * : the WikiPage (object) being saved
 * : the User (object) saving the article
 * : the new article content, as a Content object
 * : the article summary (comment)
 * : minor flag
 * : watch flag (not used, aka always null)
 * : section number (not used, aka always null)
 * : see WikiPage::doEditContent documentation for flags' definition
 * : Status (object)

Examples
$wgHooks['PageContentSave'][] = function($wikiPage, $user, $content, $summary, $isMinor, $isWatch, $section, $flags, $status){ if(true){ $status->fatal(new RawMessage("Your Error Message Here!")); } }
 * 1) Uses $status to cancel a save