Alan "- It was agreed that on unparsing a simple infoset item with no value will be treated the same as missing. Steve H to check WMB behaviour. Need to state in 4.1.2 Infoset that value is optional. " Something to note. We say that for a simple element infoset item [dataValue] has a value (either type compliant or nil) and for a complex element infoset item [dataValue] has 'no value'. Also we say that for a simple element infoset item [children] has 'no value' and for a complex element infoset item [children] it may have a value (so it could also have 'no value'). The implication therefore is that an element infoset item is deduced to be simple or complex based on the [dataValue] property. If we let a simple item take 'no value' for [dataValue] as proposed, then there is no reliable way to identify an element infoset item as simple or complex. Is that a problem in practice? After parsing, all simple items will have [dataValue] set. For items created by some other means, and presumably destined for unparsing, you could have an item with neither [dataValue] nor [children] set. We could say (1) that an element infoset item is known to be simple or complex only when it is processed by the unparser, at which point the item is matched to the DFDL schema and its type resolved. This is what broker's MRM parser does. Alternatively (2) we introduce a simple/complex flag. Note that I tried creating an MRM 'infoset' item for a string element but just gave a name and no value. The MRM serializer looked at the element, matched it to its model, found it was simple, and treated the value as NULL which invoked null processing. The XML serializer also assumed NULL. Personally I think we should adopt (1) but interpret 'no value' for a simple item as nil and not missing. Regards Steve Hanson Strategy, Common Transformation & DFDL Co-Chair, OGF DFDL WG IBM SWG, Hursley, UK, smh@uk.ibm.com, tel +44-(0)1962-815848 From: Alan Powell/UK/IBM@IBMGB To: dfdl-wg@ogf.org Date: 06/05/2010 18:12 Subject: [DFDL-WG] Minutes for OGF DFDL Working Group Call, May 05-2010 Sent by: dfdl-wg-bounces@ogf.org Open Grid Forum: Data Format Description Language Working Group OGF DFDL Working Group Call, May 05-2010 Attendees Steve Hanson (IBM) Alan Powell (IBM) Suman Kalia (IBM) Stephanie Fetzer (IBM) Tim Kimber(IBM) Apologies Steve Marting (Progeny) Mike Beckerle (Oco) 1. DFDL Specification status Alan had contacted an automotive standards body (AIAG) to generate interest in getting comments. The request had been forwarded to a number of OMG groups some of whom have at least looked at the specification. He will encourage them to make comments. Steve H had commented on the OMG MDMI site that the DFDL spec was available 2 Nils, defaults and unparsing Alan had distributed tables and examples for defaulting complex elements. Steve H had updated the tables. - emptyValueDelimiterPolicy does apply to complex elements. - on parsing a complex element is empty if its content region is empty. That is there no child delimiters or content. - on unparsing defaulting occurs if a complex item is missing or present present but has no children. Defaulting for complex elements on parsing initiator region content region infoset contains matching Not empty default exists for any missing required children complex element with child elements (real & default values) matching empty default exists for any required children emptyValueDelimiterPolicy must be initiator or both complex element with child elements (real & default values) empty Not empty default exists for any missing required children Initiator must not be specified complex element with child elements (real & default values) empty empty default exists for any required children emptyValueDelimiterPolicy must be none or Initiator must not be specified complex element with child elements (real & default values) Defaulting for complex elements on unparsing infoset contains initiator region contains content region contains not supplied supplied but with no children supplied with some children default exist for all missing required children and final representation of complex element is empty string emptyValueDelimiterPolicy none or Initiator is not specified empty empty emptyValueDelimiterPolicy initiator or both initiator string default values exist for all missing required content and final representation of complex element is not empty string Initiator is not specified initiator string representation of complex element and its children Initiator is not specified empty - The tables need to add terminator which may make them too cluttered - It was agreed that on unparsing a simple infoset item with no value will be treated the same as missing. Steve H to check WMB behaviour. Need to state in 4.1.2 Infoset that value is optional. - Conformed that emptyValueDelimiterPolicy only applies is initiator or terminator is set. - Need to describe defaulting of choices. - Confirmed that a separator is inserted/expected when postfix separator and supressedAtEnd. 3. Current Actions: Updated below 4 AOB The IBM team had questioned whether timezones should be just UTC+/- offset or should GMT and other short time zones be allowed. Alan to investigate Tim also questioned the teston/off functions. Alan stated that setting bits in a array was not possible. Will look at ISO8583 to see if needed. Meeting closed, 14:10 Next call Wednesday 12 May 2010 13:00 UK (8:00 ET) Next action: 092 Actions raised at this meeting No Action 091 The IBM team had questioned whether timezones should be just UTC+/- offset or should GMT and other short time zones be allowed. Alan to investigate 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 ... 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 progressing 31/03: work is progressing 14/04: And XML test case format has been defined and is being tested. 21/04. Schema for TDML defined. Need to define how this and the test cases will be made public 05/05: Work still progressing 084 Check behaviour of dfdl:inputValueCalc and outputValueCalc. 14/04: no prorgess 21/04: no progress 05/05: no progress 085 ALL: publicize Public comments phase to ensure a good review.. 14/04: see minutes 21/04: Press release, OMG and other standards bodies. 05/05: Alan and Steve H have contacted other standards bodies. Will ask them to add comments on spec 086 AP: Nils and Defaults during unparsing - update table 31/03: TK to documetn use cases for parsing 14/04: Investigate new property to control empty string behaviour. 21/04: After investigation a new property is not required. New rules developed and tables updated. Need examples of complexTypes to confirm tables apply. Review Nils, defaulting spec section. 05/05: Discussed defaulting complex elements. Tables updated but need to add terminator. SH; to confirm WMD behaviour when infoset item has no value on unparsing Need to describe defaulting choices. 088 define semantics of choiceKind 'fixedLength' 31/03: TK to provide definition of calculable length. Investigate PL/I varchars and Cobol occurs dependingon. 14/04Tim had distributed a document starting the definition of calculable length for the longest choice member. Alan had done some investigation of COBOL occurs depending on and when used in the working section of a program then the maximum storage was reserved but when used in the linkage section the dependent number was uses. We need to understand how the WMB COBOL importer deals with ODO. 21/04: Need to define 'calculable length' and WMB importer ODO behaviour. 05/05: TK: Still need definition of calculable length. SKK: WMB COBOL imported behaviour with ODO 091 The IBM team had questioned whether timezones should be just UTC+/- offset or should GMT and other short time zones be allowed. Alan to investigate Closed actions No Action 090 Semantics of separatorPolicy 14/04: Discussion on detecting when complex types should be defaulted. Examples needed. 21/04: Complex defaulting examples needed for new rules 05/05: Subsumed into action 086 defaults. CLOSED 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 098 occursCountKind is parsing only 099 nilValue and OccuresStopValue cannot have an expression. On unparsing only outputValueCalc can have a forward reference. 100 Need to state in 4.1.2 Infoset that value is optional. Regards Alan Powell Development - MQSeries, Message Broker, ESB IBM Software Group, Application and Integration Middleware Software ------------------------------------------------------------------------------------------------------------------------------------------- IBM MP211, Hursley Park Hursley, SO21 2JN United Kingdom Phone: +44-1962-815073 e-mail: alan_powell@uk.ibm.com 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