Last modified: 2012-07-31 22:57:00 UTC
The popularity of this has been increasing. Many wikis use it but it is rather painful to copy the necessary .css and .js code. The .css/.js hack is probably inefficient.
I think this would be a fine addition.
This was fixed by Krinkle on 2010 (r78914) which implemented the jQuery.makeCollapsible plugin on [[mw:MediaWiki 1.18]].
For more info, see:
* [[mw:Manual:Collapsible elements]]
* [[mw:ResourceLoader/Default modules#jQuery.makeCollapsible]]