[ticker-dev] Elvin presence specification draft 0.2

[Phillips, Matthew]

Julian:
"David mentioned some ontological issues the other day. this
related to another discussion about attriubute naming in notifs
in general.  for the moment, I don't think its worth worrying too
much about this?  I'm happy to implement the proposed spec, and
perhaps use it as the basis for further name disussions in future."

This sounds interesting.  Can you or David summarise this at all?

Klaus:
"Btw, can we use this scheme for bots also (bots could have their own
group - botspot, or whatever)?"

Absolutely. I's say either use one "bots" group or maybe several with a
naming convention like "bots.dstc", "bots.public" etc.


Several people have noted the "|" convention for formatting group sets.  The
reason for this is that clients will often want to subscribe for presence
info for a single group, and with this convention we can just use a
subscription like:

  require(Presence-Info) && contains(Groups, "|dsto|")

This will then catch notifications where the Groups field is just "|dsto|",
or where it is "|elvin-sse|dsto|" and also distinguishes it from
"|ftd.dsto|bobco|".  Just using contains(Groups, "dsto") could catch other
notifications, and the alternative, where we use ";" as a separator would
need the horrible expression:

  contains(Groups, ";dsto;") || ends-with(Groups, ";dsto") ||
begins-with(Groups, "dsto;") || Groups == "dsto"

The reason to choose "|" over ";" or "," is that it looks better when used
this way ie "|dsto|elvin-sse|" looks nicer than ";dsto;elvin-sse;", IMHO.

Cheers,

Matthew.