2009/4/27 Prunka, Sean <PRUNKAS(a)battelle.org>rg>:
The general API documentation is good (though
daunting) for making use of
existing API calls, but what little information I did find
(
http://www.mediawiki.org/wiki/API:Calling_internally) is limited on
creating a new API extension, especially when mimicking output of a 3rd
party extension or custom written Special Page.
It's not limited to creating a new extension per se: adding a new
class for an API module and registering it at the right places is
something that can also be done "on the side" of a "regular"
extension
(in fact, it's almost always used this way, see AbuseFilter and
FlaggedRevs for examples).
If you want to mimick the output of a special page, you'll have to get
the data the same way the special page does; usually, that's through a
database query. For examples of how to do database queries in API
modules, see the ApiQuery*.php files in core
(/trunk/phase3/includes/api in SVN).
Roan Kattouw (Catrope)