Re: VCAR: RIGHTS Value Type Ambiguous

["Graham Gilmore" <grahamg@xxxxxxxxxxx>]

----- Original Message -----
From: "Doug Royer" <Doug@xxxxxxxxx>
To: <ietf-calendar@xxxxxxx>
Sent: Monday, January 21, 2002 4:52 PM
Subject: Re: VCAR: RIGHTS Value Type Ambiguous


> > Given that the semantics of OBJECT and VALUE is not defined
> > anywhere, you can only claim that this is YOUR interpretation
> > of this VCAR.
>
> As I wrote VCARs, I guess I can :-)

    Perhaps; but it needs to be explicit in the draft for EVERYONE to have
the same interpretation, else interoperability will be next to impossible.

    If I follow this debate correctly (and no guarantees there ;), Bernard
says :

"The problems lies in the fact that the OBJECT and VALUE
rule parts have been overloaded to allow us to specify
all of the following:

(1) The set of stored objects on which the specified
    ACTION is granted or denied (i.e., the selected
    objects).

(2) The part of the selected objects on which the
    specified ACTION is granted or denied.

(3) Restrictions on the submitted objects."

    Where the assumption is that the OBJECT and VALUE rule parts each have
ONE of the listed meanings.  (Feel free to correct me if I'm wrong here,
Bernard)

    You seem to be saying that, Yes, OBJECT and VALUE rule parts can have
all of those meanings; in fact they have ALL of those meanings, at the same
time, always.  (Again, feel free to correct me if I'm interpreting your
intention poorly)

    Example 1:

    BEGIN:VCAR
    CARID:UPDATEPARTSTATUS
    GRANT:UPN=*;ACTION=MODIFY
     ;OBJECT=PARTSTAT:VALUE=*
     ;OBJECT=ATTENDEE;VALUE=SELF
    END:VCAR

    So, in this example, the OBJECT and VALUE rule parts specify (1) The
target of the VCAR, that is, the PARTSTAT parameter (with any value)
combined with an ATTENDEE value of SELF, (2) The parts of the selected
objects that can be modified, that is, the CU/CUA can modify a PARTSTAT with
any value, and any ATTENDEE with a value of SELF, and (3) The restrictions
on the final submitted objects, that is, after modifying the object it must
have a PARTSTAT of any value and an ATTENDEE value of SELF.

    The only thing that remains confusing is, how can one be sure that the
PARTSTAT in the VCAR applies (as is presumably the intention) to the
ATTENDEE property whose value is SELF?  This implicit link between the two
OBJECTs isn't expressed anywhere in the VCAR.

    As an example, suppose I want to DENY READ rights for everybody on
events whose DTSTART TZID and DTEND TZID are EST and PST respectively, and
vice versa (for example, an organization is very security-conscious and
doesn't want to permit the viewing of any events corresponding to business
flights of its executives).

    (pardon my poor VCAR grammar if there are any mistakes, but I'm sure
you'll get the drift)

    BEGIN:VCAR
    DENY:UPN=NONOWNER;ACTION=READ
     ;OBJECT=DTSTART:VALUE=*
     ;OBJECT=TZID;VALUE=EST5EDT
     ;OBJECT=DTEND:VALUE=*
     ;OBJECT=TZID;VALUE=PST8PDT
    END:VCAR


    How would a CUA or CS be able to figure out which TZID goes with which
property?


    Graham