Re: Default TARGET

[Bruce_Kahn@xxxxxxxxxxxxxxxx]

Craig wrote on 05/29/2003 07:27:08 PM:
> In the current draft the ABNF for TARGET indicates it is optional.
 

Another reason why I think the ABNF
needs to be reformatted to be more akin to 2445.  The current formatting
makes mistakes or odd data likely.

> How does the working group feel about defaulting
the TARGET in this 
> manner? Or should TARGET always be explicit?  Either way, the
draft 
> needs adjustment to clarify the issue.

I think we should fix up the draft and
NOT default TARGET.  Heres why:

1: Not everyone has just 1 calendar.
 I happen to have 3 I use; 1 for work, 1 for personal/family and 1
for my Red Cross activities.  As such if my CS is to default a TARGET
to a particular calendar I now have to add new infrastructure to the CS.
 I now have to provide some means to match a UPN to a particular TARGET
(a new CS requirement).  I also need to have some means to change
this.  However many here will yell "Administration issue!"
and say its out of scope for CAP.  Great, a last minute feature/side
effect that requires some OOB mechanism to manage from Day 1.

2: The behaviour for the changing identity
case (IDENTIFY command) is unclear at best.  Should my AA now default
to my 'primary' calendar when she assumes my identity?  I would expect
not but some could argue so.

3: For the case where Im doing acutal
Scheduling activities I may want to refer to my calendar and  that
of others.  Then Id have to specify a TARGET of my primary calendar.
 Since the TARGET can be a relative calendar identifier which is not
likely to be overly long, what is the real cost savings by defaulting it?
 9 octets plus the relcalid length.  Not a whole lot of extra
savings...

4: There is no way for the CUA to find
out what the default TARGET is from the CS so there is no way for the CUA
to know what tell the CU or when to use a different relcalid.  Just
how would my CUA know it needed to send TARGET:BrucesFamilyCalendar or
TARGET:BruceRedCross but not TARGET:BrucesWorkCalendar??

5: Making assumptions, especially for
stuff like DELETE, could be disasterous if the wrong default is used (and
the CUA has 0% chance of determining what the default value is!).  Imagine
the user thinking they are cleaning out an old project calendar and infact
they just erased the current one (or their personal one or ...)  =:^(

I see lots of questions / concerns about
data safety and usability and the only real cost trade off is "9 octets
+ strlen(relcalid)" vs cleaning up the ABNF in CAP.  I for one
like it clearly spelled out in the text/ABNF since the savings is not likely
to be that big anyway (compared to the cost of going "off box"
to the CS, etc).  I would vote for fixing the text and not defaulting
anything!

Bruce
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