[Standards] Entity Capabilities Woes

Remko Tronçon remko at el-tramo.be
Thu Mar 15 14:23:58 UTC 2007

> Hrm.  Thanks Remko!  That's very helpful!  Is the intention of this
> XEP to do away with "just announcing your capabilities via disco"?
> Like should I expect to no longer get useful results from a standard
> disco info query?  Is the client expected to duplicate the fact that
> it supports muc both in the capabilities node and in it's ... "base"
> node?  Or is it something that I would really need to do something like:

Disco on the base node should return the union of all features
(including extensions). With caps, it should in theory no longer be
necessary to disco on the full node explicitly, unless you don't have
a presence subscription from the entity, or the entity doesn't use
presence (like a server).

As for clients not supporting caps: It does not make sense to disco
them for features, as you'll have to do that at least every time the
person signs on (he/she might have changed clients), and to be
completely correct, *every* time you need a feature (he/she might have
set an option in the meantime). Therefore, if a client does not use
caps to announce its capabilities, you shouldn't query them at all,
and assume they have every feature (and use error dialogs if your
assumption was wrong).

On a sidenote: I think that full disco is done each time a file is
transferred, but that is because there were no caps back then.


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