Manual:$wgLegacyJavaScriptGlobals

ResourceLoader: $wgLegacyJavaScriptGlobals
Whether or not to assign configuration variables to the global window object.
Introduced in version:	1.18.0 (r87856)
Deprecated in version:	1.35.0 (Gerrit change 618030; git #0b23e103)
Removed in version:	1.37.0 (Gerrit change 678716; git #99d4ad59)
Allowed values:	(boolean)
Default value:	false (1.35-1.36) true (1.18-1.34)
Other settings: Alphabetical | By function

Details

Whether or not to assign configuration variables to the global window object.

If this is set to false, old code using deprecated variables like:

if ( window.wgRestrictionEdit ) ...

or:

if ( wgIsArticle ) ...

will no longer work and needs to use mw.config instead. For example:

if ( mw.config.exists('wgRestrictionEdit') )

or:

if ( mw.config.get('wgIsArticle') )