Thread:Talk:Universal Language Selector/Is there some expression that evaluates to the current language?

E.g., something like that gives me the code for the current interface language?

Background, in case there's another solution: My wiki is multilingual. I use categories heavily, for example Category:Dances. The text at the top of that page should be displayed in the current interface language. So on that page I put and create pages MediaWiki:CategoryDancesHeader/XX as appropriate. This works fine.

For Hebrew I also must set the overall right-to-left orientation of the page. On a normal page I do that by putting at the top. But that doesn't work in this case. It looks like setting PAGELANGUAGE on a page doesn't effect pages into which that page is transcluded.

A solution is to set PAGELANGUAGE at the top of Category:Dances itself with something like. How can I get my hands on the current language in order to do this?

I'd also think this functionality is useful enough to be provided directly, e.g., let to set the page language to the current language.