Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, March-18-2009 Attendees Alan Powell (IBM) Steve Hanson (IBM) Dave Glick (drac) Suman Kalia (IBM) Apologies Mike Beckerle(Oco) <Updated> to correct dfdl:format syntax to set common properties Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, March-18-2009 Attendees Alan Powell (IBM) Steve Hanson (IBM) Dave Glick (drac) Suman Kalia (IBM) Apologies Mike Beckerle(Oco) 1. Specialized Annotations The whole call was taken up discussing the "dfdl:sequence and other specialized annotations" proposal emailed by SH. In summary proposes - the use of specialized annotations on each schema object. eg dfdl:sequence - a separate set of scoped properties for each specialization. <xs:complexType name="myType"> <xs:annotation><xs:appinfo source=?http://www.ogf.org/dfdl/?> <dfdl:complexType> <dfdl:sequence lengthKind="implicit" ... /> <dfdl:element lengthKind="delimited" ... /> </dfdl:complexType> </xs:appinfo></xs:annotation> There was general agreement with the proposal but a lot of discussion about the two issues that SH identified. a. The meaning of short form annotations on complex type. <xs:complexType name="myType" dfdl:lengthKind="implicit" ... > It is not clear which specialized annotation scope the short form properties on complex type should apply to. There was a lot of discussion between 1) disallowing short form annotation on complex type and 2) applying them to all specialized scopes. Disallowing short form is simple but makes complex type different, forces long form which is much more verbose, means common properties, eg encoding, to be specified the same on multiple specialized annotations. This is a particular problem for element and simple type. However applying short form to all specialization introduces a new level of inheritance and consequent complexity. b. You are forced to set common properties in multiple places in defineFormat. <xs:annotation><xs:appinfo source=?http://www.ogf.org/dfdl/?> <dfdl:defineFormat> <dfdl:sequence encoding="UTF-8" ... /> <dfdl:element encoding="UTF-8" ... /> <dfdl:simpleType encoding="UTF-8" ... /> <dfdl:choice encoding="UTF-8" ... /> <dfdl:any encoding="UTF-8" ... /> </dfdl:defineFormat> </xs:appinfo></xs:annotation> Possible solution is to use dfdl:format to set common properties <xs:annotation><xs:appinfo source=?http://www.ogf.org/dfdl/?> <dfdl:defineFormat> <dfdl:format encoding="UTF-8" ... /> <dfdl:sequence ... /> <dfdl:element ... /> <dfdl:simpleType ... /> <dfdl:choice ... /> <dfdl:any ... /> </dfdl:defineFormat> </xs:appinfo></xs:annotation> The consensus was that there should be a way to provide common properties so this solution was preferred and you could use the same for complex type <xs:annotation><xs:appinfo source=?http://www.ogf.org/dfdl/?> <dfdl:complexType> <dfdl:format encoding="UTF-8" ... /> <dfdl:sequence ... /> <dfdl:element ... /> <dfdl:simpleType ... /> <dfdl:choice ... /> <dfdl:any ... /> </dfdl:complexType> </xs:appinfo></xs:annotation> It was agreed that this was the preferred solution. During the discussion SK asked what was the precedence of short and long-form properties on the same object. AP subsequently sent SK section 10.3 which states that long-form have precedence over short-form. 2. AOB To be discussed - Escape Schemes - Validation ranges and exclusion lists - Consuming extraneous data after schema has be used. - 'Floating' definitions - Actions Next call 25 March 14:00 UK Meeting closed, 15:00 GMT Actions raised at this meeting No Action Current Actions: No Action 012 AP/SH: Update decimalCalendarScheme 10/9: Not allocated yet 17/9: No update 24/9: Add calendar binary formats to actions 22/10: No progress 16/1: proposal distributed and discussed. Will be redistributed 21/1: add locale, 04/02: changed from locale to specific properties 18/2: Need more investigation of ICU strict/lax behaviour. 020 SH: Resolve packedDecimalSignCodes behaviour depends on NumberCheckPolicy 22/10: No progress 10/12: added how to decide to overpunch and sign position 11/02: proposal largely agreed. SH to make minor changes 18/02: AP to document unsigned type behaviour 25/02: no progress 023 MB: Review Schema 1.1 29/1: AP and SH to talk to Sandy Gao 04/02 Call arranged for Friday 11/02: Call took place. Identified useful changes. Consolidate with previous list. 04/03: decided to stay on Schema 1.0. 024 String XML type 025 Escape schemes 21/1: discussed requirements 04/02: AP/SH to describe behaviour for known length text fields. Need to discuss if comment escapes should be supported. 11/02 new draft distributed: 18/02: SH up document concerns 25/02: SH and AP have refined proposal ready for approval. 04/03: SH and AP have further refined proposal. 11/03: discussed. suggested a simplified proposal be evaluated. 18/03: SH and AP had further discussions on simplified proposal 026 SH: Envelopes and Payloads 027 Property precedence tables 028 Variable markup 029 valueCalc (output length calculation) 031 DG: Review dfdl v033 11/02: Initial comments received 18/02: Will include work items 5 and 12. 11/03: complete 032 DG: Investigate compatibility between DFDL infoset and XDM 033 04/03: Assert/Discriminator semantics. AP to document. TK to check uses of discriminator besides choice. 034 04/03: AP remove redundant properties Closed actions: 034 Work items: No Item 001 String XML type (Ian P) - Apr 30, 2008 002 Escape schemes (Ian P) - Apr 30, 2008 003 Variables - ??, 2008 (Mike) 005 Improvements on property descriptions - ??, 2008 (All - split TBD) 006 Envelopes and Payloads (Steve) - Apr 30, 2008 007 (from draft 32) valueCalc (Mike) - ??, 2008 mostly complete 008 (from draft 32) Property precedence for writing (Steve) - under review 009 (from draft 32) Variable markup (Steve) - Mar 31, 2008 proposal needs writing up 010 (from draft 32) Assertions, discriminators and choice, including discussion of timing option (Suman) - Mar 31, 2008 * in progress * 011 (from draft 32) How speculative parsing works (combining choice and variable-occurence - currently these are separate) ??, 2008 (IBM) in progress 012 (from draft 32) Reordering the properties discussion: move representation earlier, improve flow of topics ??, 2008 (Alan) * not started * 025 Augmented infoset and unparsing (Alan) added but needs work 026 Remove duration complete - specification updated Alan Powell MP 211, IBM UK Labs, Hursley, Winchester, SO21 2JN, England Notes Id: Alan Powell/UK/IBM email: alan_powell@uk.ibm.com Tel: +44 (0)1962 815073 Fax: +44 (0)1962 816898 Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU -- dfdl-wg mailing list dfdl-wg@ogf.org http://www.ogf.org/mailman/listinfo/dfdl-wg Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU