Last modified: 2013-03-08 11:23:56 UTC
As far as I can tell, Extension:Diff is all-or-nothing: you can use it to generate all diffs or none. It would be nice if this were more configurable, allowing you to enable it for a particular content model.
You seem to misunderstand what Diff is. It is a PHP library for computing an representing (as in PHP objects) diffs. It does not even know MediaWiki exists, much less content models or namespaces.
To clarify: it is the content handler linked to some content model that decides which Action class is used to handle diff view requests. Those action classes can then compute and display diffs as they like, including using the Diff library for this computation. This is what Wikibase does for its diff view handling. If you see shortcomings there, it's a Wikibase issue. If you think all content models should be able to use Diff, it is a MW core issue.
