[ticker-dev] Elvin presence specification draft

[Phillips, Matthew]

Replies to David and Martin.  I would have liked to spend more time on this
reply, but I've got my hands full at the moment.

>   Martin> Firstly, the status field should not be a string, or else
>   Martin> why do we have a status text field. I understand the concept
>   Martin> of making it readable *but* its only readable in English :-)
>   Martin> Sooooo to that end I put forward that the status field
>   Martin> should be a machine readable value (a number) that has the
>   Martin> same meaning in any language.
> 
> i don't really care either way here.  both are defined patterns of
> bits.  if one particular language group can benefit from simpler
> recognition of that bit pattern, that's fine with me.  but not having
> that is also ok if there's some benefit.

I with David here, you might as well choose a representation that is
meaningful to _someone_

>   Martin> This leaves us with an "online" status change and an
>   Martin> "off-line" status change with "online" being one of
>   Martin> available/unavailable
> 
> if you rename "available" to "online" here, don't you have the same
> thing?  

There is no "available" status, just "online"

>   Martin> Appointment|Lunch|Coffee|....more.....
> 
> the only thing i can see being actually useful, from a
> machine-readable point of view, is an expected duration of the lack of
> availability.
> 
> i don't see any benefit in having different codes for "meeting" vs
> "lunch" (for example).

The reason for having a standard meaning for Status = 'online',
'unavailable' and 'offline' is so that clients can interpret them - for
example warn you when you're going to send a message to someone that is
'unavailable'.  And as far as the client is concerned 'Appointment', 'Lunch'
and 'Coffee' are just as unavailable as anything else.  

> for my usage, "offline" is useless.  i'm never (or so infrequently as
> to be insignificant) offline.  one or more of my sessions (and
> therefore presence tools) is running at all times.

Yes, offline is a bit of a problem, especially when you're running multiple
clients where one sends offline: how do the other people know you're
offline?  In fact it's the same problem when you're running two clients and
then one sets your status to 'unavailable?'  You should still be marked
'online', but most clients would 'downgraded' you to unavailable. Possibly
the 'online' client could notice this and send an update, but this could
happen out of order.  More thought required...

Matthew.