priority specification bug
Martin Konold
martin.konold at erfrakon.de
Tue Feb 14 06:12:22 CET 2006
Hi,
we need a solution for priorities.
KO: 1-9 (*) with 1 being highest
OL: low, normal, high
Kolab Format Specification: 1-5 with 1 being highest.
ical rfc 2445: 0-9 with 1 being highest
This situation is beyond my understanding. Does anyone know why the Kolab
Format Specification
http://www.kolab.org/doc/kolabformat-2.0rc3-html/c254.html has defined the
1-5 range? Is this a plain bug?
I see two solutions:
1.) change the Kolab format specification to the common denominator. (OL
behaviour with only three values)
2.) use a mapping which tries to preserve as much information as possible but
which is "lossy" in some case. This means changing the spec to use 9 values.
(**)
All: Do you agree that the current Kolab Format Specification for priorities
using five values is simply a bug and violating any standard including KO,OL
and ical RFC 2445?
David: Do you consider 1.) a possible solution?
Joon,Johannes: In case 2.) will adopted are you willing to add the required
complexity to your products soon?
I personally think that 1.) is fully sufficient as choosing between 10
priority values is imho overengineered but using 10 levels (0+1-9 with 0
being undefined) is defined in the ical RFC and therefore a real standard.
(*) To add to the confusion 1 is mapped to highest and 9 to lowest priority.
(**) It shall be a best effort approach preserving as much information as
possible while being lossless in non-mixed environments. If
transformation/mapping is required (the priority property is
written/modified) then the mapping rules are already defined in RFC 2445.
4.8.1.9 Priority
Property Name: PRIORITY
Purpose: The property defines the relative priority for a calendar
component.
Value Type: INTEGER
Property Parameters: Non-standard property parameters can be
specified on this property.
Conformance: The property can be specified in a "VEVENT" or "VTODO"
calendar component.
Description: The priority is specified as an integer in the range
zero to nine. A value of zero (US-ASCII decimal 48) specifies an
undefined priority. A value of one (US-ASCII decimal 49) is the
highest priority. A value of two (US-ASCII decimal 50) is the second
highest priority. Subsequent numbers specify a decreasing ordinal
priority. A value of nine (US-ASCII decimal 58) is the lowest
priority.
A CUA with a three-level priority scheme of "HIGH", "MEDIUM" and
"LOW" is mapped into this property such that a property value in the
range of one (US-ASCII decimal 49) to four (US-ASCII decimal 52)
specifies "HIGH" priority. A value of five (US-ASCII decimal 53) is
the normal or "MEDIUM" priority. A value in the range of six (US-
ASCII decimal 54) to nine (US-ASCII decimal 58) is "LOW" priority.
A CUA with a priority schema of "A1", "A2", "A3", "B1", "B2", ...,
"C3" is mapped into this property such that a property value of one
(US-ASCII decimal 49) specifies "A1", a property value of two (US-
ASCII decimal 50) specifies "A2", a property value of three (US-ASCII
decimal 51) specifies "A3", and so forth up to a property value of 9
(US-ASCII decimal 58) specifies "C3".
Other integer values are reserved for future use.
Within a "VEVENT" calendar component, this property specifies a
priority for the event. This property may be useful when more than
one event is scheduled for a given time period.
Within a "VTODO" calendar component, this property specified a
priority for the to-do. This property is useful in prioritizing
multiple action items for a given time period.
Format Definition: The property is specified by the following
notation:
priority = "PRIORITY" prioparam ":" privalue CRLF
;Default is zero
prioparam = *(";" xparam)
privalue = integer ;Must be in the range [0..9]
; All other values are reserved for future use
The following is an example of a property with the highest priority:
PRIORITY:1
The following is an example of a property with a next highest
priority:
PRIORITY:2
Example: The following is an example of a property with no priority.
This is equivalent to not specifying the "PRIORITY" property:
PRIORITY:0
Regards,
-- martin
--
http://www.erfrakon.com/
Erlewein, Frank, Konold & Partner - Beratende Ingenieure und Physiker
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