1. DFDL Specification status 2 Nils, defaults and unparsing 3. Current Actions: 4 Expressions during Unparsing. --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 1. DFDL Specification status 2 Nils, defaults and unparsing Steve H, Tim and Alan have had further discussions and concluded and new property was not required so propose - Elements that are zero length and elements that are 'missing' from the data stream should be treated the same. - missingValueInitiatorPolicy should be renamed to emptyValueInitiatorPolicy to distinguish from a missing infoset value on unparsing - Any 'initiator' policy needs to also include terminators so the enumerations should be extended to "none", "initiator", "terminator", "both". and the properties renamed emptyValueDelimiterPolicy and nilValueDelimiterPolicy . The tables have been reworked Nils and Defaults on Parsing initiator region content region Logical Value matching content content matches nilValue nilValueDelimiterPolicy must be initiator or both nil Content does not match nilValue parse content to get value matching empty empty string is a nil value nilValueDelimiterPolicy must be initiator or both nil A default is specified emptyValueDelimiterPolicy must be initiator or both default value (may be nil, empty space or value) empty content content matches nilValue nilValueDelimiterPolicy must be none nil content does not match nilValue Initiator is not specified parse content to get value Initiator is specified ERROR empty empty empty string is a nil value nilValueDelimiterPolicy must be none nil A default is specified emptyValueDelimiterPolicy must be none default value (may be nil, empty space or value) Nils and Defaults on Unparsing Logical Value initiator region contains content region contains Nil (implies nillable) nilValueDelimiterPolicy none empty representation of nil nilValueDelimiterPolicy initiator or both initiator string "" (empty string) (type is xs:string or xs:hexBinary) emptyValueDelimiterPolicy none empty empty emptyValueDelimiterPolicy initiator or both initiator string missing useNilForDefault nilValueDelimiterPolicy none empty representation of nil nilValueDelimiterPolicy initiator or both initiator string default is empty string (type is xs:string or xs:hexBinary) emptyValueDelimiterPolicy none empty empty emptyValueDelimiterPolicy initiator or both initiator string Other default initiator string representation of the default value. a non-nil non-empty-string value initiator string representation of the logical value 3. 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. 084 Check behaviour of dfdl:inputValueCalc and outputValueCalc. 14/04: no prorgess 085 ALL: publicize Public comments phase to ensure a good review.. 14/04: see minutes 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. 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. 089 Need to be able to define unsigned decimal and integer 31/03: MB to agree proposed solution 14/04: MB to agree proposed solution 090 Semantics of separatorPolicy 14/04: Discussion on detecting when complex types should be defaulted. Examples needed. 4 Expressions during Unparsing. In order to reduce complexity and potential performance problems it is proposed to - nilValue and occursStopValue should NOT be able to take an expression. - Very few properties should be allowed to have forward references. Here's the list of properties that can take an expression, along with some suggested restrictions on forward referencing: byteOrder backward reference only encoding backward reference only initiator backward reference only terminator backward reference only separator backward reference only outputNewline backward reference only length simple elements : backward reference only. complex elements : forward reference allowed Quote "When unparsing with dfdl:lengthKind="explicit", the calculation of dfdl:representationLength() returns the value of the dfdl:length property." A simple element's length needs to be known in advance, else it cannot be parsed. A complex element's length might get resolved while parsing its content, so a forward reference within the scope of the complex element is possible. Having said that, we might want to impose a restriction in IBM's DFDL processor v1.0 that only backward references are allowed. escapeCharacter backward reference only escapeEscapeCharacter backward reference only textNumberDecimalSeparator backward reference only textNumberGroupSeparator backward reference only textNumberExponentCharacter backward reference only binaryFloatRep backward reference only textBooleanTrueRep backward reference only textBooleanFalseRep backward reference only nilValue backward reference only Not clear why this needs to be specified as an expression. ( may already be on a list of open issues somewhere ) nilIndicatorPath backward reference only occursCount backward reference only occursStopValue Not clear why this needs to be specified as an expression. [inputValueCalc] [Parser only] Backward reference only outputValueCalc Forward or backward reference 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