Open Grid Forum: Data Format Description Language Working Group

OGF DFDL Working Group Call, March 17-2010

Attendees
Suman Kalia (IBM)
Steve Hanson (IBM)
Alan Powell (IBM)  
Steve Marting (Progeny)  
Stephanie Fetzer (IBM)
Mike Beckerle (Oco)

Apologies
Tim Kimber(IBM)


Steve H reported on the DFDL presentation at OGF 28
Overall OGF registered attendees thought to be around 250.

Number at DFDL session: 7.  Apart from Erwin (Data AD), DFDL was new to everyone.

Notes from session (from minutes taken by Erwin Laure based on questions asked):

Draft 040 has been submitted to OGF and will be reviewed by the technical committee on March 30th. It is expected to go out for public comment in early April.

There needs to be some publicity to ensure that enough comments are made.
Mike suggested a press release from his company with IBM comment.  Action raised
May be able to get IBM representatives on other standards bodies such as ACCORD. OMG, to interest their members,
Should contact all the contributors to the WG to ask them to review.
Mike will update the information he sent in response to an RFI from OMG

1 Process for dealing with internal issues during Public comment phase.
The public comments process will be used to make updates


2. Nils and Defaults during unparsing
The table 17 in section 13.16.2 was corrected in draft 40 but here are still some ambiguities, for example when nil is the default.
Logical Value
nilValueInitiatorPolicy
Has default value specified
missingValueInitiatorPolicy
initiator region contains
content region contains
Nil
(implies nillable)
prohibited
don't care
don't care
empty
representation of nil based on nilKind, nilValue, etc.
required
initiator string
"" (empty string)
Note that this implies that the element type is xs:string
don't care
prohibited
empty
empty string
required
initiator string
a non-nil non-empty-string value
don't care
don't care
initiator string
The representation of the logical value
Not supplied
don’t care
Yes
(non-empty sting)
don't care
Initiator string
The representation of the default value.
Yes
(empty string)
prohibited
empty
empty
required
initiator string
empty


Alan will go update the table.

3 dfdl:choiceKind

The main issues  are:
a) The calculation of the length of the longest branch is not obvious.
b) The length units to use - the dfdl:lengthUnits property does not exist on a choice
c) The name could be better

Proposal is therefore to retain the property but to:
i) State the conditions that must apply to use this property, and enforce them in the validator => schema definition error otherwise
ii) Decouple the choice from its parent by calculating the length of each branch based solely on the properties of the branches components, irrespective of any parent dfdl:lengthKind

Alan document the problem. Name change agreed.

4 DFDL time functions

fn:timezone-from-dateTime Returns the timezone from an xs:dateTime value.
fn:timezone-from-date Returns the timezone from an xs:date value.

fn:timezone-from-time Returns the timezone from an xs:time value.
Function
Meaning
fn:adjust-dateTime-to-timezone Adjusts an xs:dateTime value to a specific timezone, or to no timezone at all.
fn:adjust-date-to-timezone Adjusts an xs:date value to a specific timezone, or to no timezone at all.
fn:adjust-time-to-timezone Adjusts an xs:time value to a specific timezone, or to no timezone at all.



All return an xs:duration. Do we need these functions?

As there is no known use case for these functions they will be dropped.

Meeting closed, 14:10

Next call  Wednesday 17 March January 2010  13:00 UK  (9:00 ET)
Call will be for one hour only
NOTE: East coast is 4 hours behind the UK for the next two weeks

Next action: 087

Actions raised at this meeting
No
Action
085
ALL: publicize Public comments phase to ensure a good review..
086
AP: Nils and Defaults during unparsing - update table

Current Actions:
No
Action
066
Investigate format for defining test cases
25/11:IBM to see if it is possible to publish its test case format.
04/12: no update
09/12: no update
16/12: reminded dent to project manager
23/12: SH will send another reminder.
06/01: Another reminder will be sent
13/01: no update
20/01: no update
27/01: no progress
29/01: no progress
03/02: IBM is still investigating
10/02: IBM is still investigating
17/02: IBM is willing in principle to publish the test case format and some of the test cases. May need some time to build a 'compliance suite'
24/03: No progress
03/03: Discussions have been taking place on the subset of tests that will be provided.
10/03: work is progressing
17/03: work is progressin
084
Check behaviour of dfdl:inputValueCalc and outputValueCalc.
085
ALL: publicize Public comments phase to ensure a good review..
086
AP: Nils and Defaults during unparsing - update table

Closed actions
No
Action

Work items:
No
Item target version status
005
Improvements on property descriptions not started
012
Reordering the properties discussion: move representation earlier, improve flow of topics not started
036
Update dfdl schema with change properties ongoing
042
Mapping of the DFDL infoset to XDM none not required for V1 specification
070
Write DFDL primer
071
Write test cases.
083
Implement RFC2116
097
Remove functions that returns duration



 
Regards
 
Alan Powell
 
Development - MQSeries, Message Broker, ESB
IBM Software Group, Application and Integration Middleware Software
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