Hundreds of globals are initialized on startup by MediaWiki. The majority of these global variables are configuration settings that are set in DefaultSettings.php and LocalSettings.php. (See Manual:Configuration settings for documentation on these variables.) There is no comprehensive documentation for the remaining few hundred globals, however, some of the most important ones are listed below. They are typically initialized either in index.php or in Setup.php.
- $mediaWiki - MediaWiki object, the main base class for the MediaWiki software. Initializes the
$wgArticleobjects, and executes the URL actions.
- $wgArticle - Article object corresponding to
$wgTitle. (deprecated in 1.19)(removed in 1.23)
- $wgContLang - Language object associated with the wiki being viewed. (removed in 1.36)
- $wgLang - Language object selected by user preferences.
- $wgLoadBalancer - LoadBalancer object, manages database connections. (removed in 1.13)
- $wgMessageCache - Message cache to manage interface messages. (removed in 1.18)
- $wgOut - OutputPage object for HTTP response.
- $wgParser - Parser object. Parser extensions register their hooks here. (deprecated in 1.32)
- $wgRequest - WebRequest object, to get request data.
- $wgTitle - Title object created from the request URL. (deprecated in 1.19) Note: This variable should be avoided when possible, more sane title objects are usually available.
- $wgUser - User object for the user associated with the current request.