Agenda for OGF DFDL WG call 14 April 2010- 13:00 UK (8:00 ET)

1. DFDL Specification status There has been no announcement of the public comment period so presumably it hasn't started. Chasing email sent. 2 Nils, defaults and unparsing Logical Value initiator region contains content region contains Nil (implies nillable) nilValueInitiatorPolicy 'prohibited' empty representation of nil nilValueInitiatorPolicy 'required' initiator string "" (empty string) (type is xs:string or xs:hexBinary) missingValueInitiatorPolicy 'prohibited' empty empty missingValueInitiatorPolicy 'required' initiator string missing useNilForDefault nilValueInitiatorPolicy 'prohibited' empty representation of nil nilValueInitiatorPolicy 'required' initiator string default is empty string (type is xs:string or xs:hexBinary) missingValueInitiatorPolicy 'prohibited' empty empty missingValueInitiatorPolicy 'required' 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 Other changes: missingValueInitiatorPolicy Enum Valid values ?required', ?prohibited' Specifies whether to expect an initiator when an element is missing. Ignored unless dfdl:initiator is specified and is not "" (empty string). 'required'- Indicates that the dfdl:initiator followed by empty content is the required syntax to indicate that the element is missing. ?prohibited' - Indicates that empty content is the required syntax to indicate that the element is missing. The presence of an initiator implies that real content must follow. Use of ?prohibited' implies an ordered sequence. If used on an initiated element of an unordered group it is a schema definition error. If the element is required, defaulting occurs as defined above. This property also applies on unparsing, when the data to be written (after nil value and default value processing) is empty content. Annotation: dfdl:element Need to decide whether there needs to be a differentiation between 'zero length content' and 'missing from the data stream'. Tim will document the parsing use cases so we can verify the parsing table. 3 dfdl:separatorPoilicy. dfdl:separatorPolicy enumeration definitions are not complete as they do not discuss arrays or defaulting. separatorPolicy="required" All the separators must be there. No group member, except for required members with a default, may be omitted from the data stream. Every group member must have a separator in the correct position. Optional members and variable-occurrence arrays will be allowed, separators will be expected for all maxOccurs ** It is a schema definition error if maxOccurs="unbounded" for any member of the group separatorPolicy="suppressed" Any group member ( optional or required with a default) can be omitted from the data stream, in which case its separator must may also be omitted. For prefix and infix, if a separator is found then another group member is expected. For postfix, if enclosing markup is not found immediately after a postfix separator then another group member is expected. Enclosing markup or end of data can occur where an infix or prefix separator is expected. This terminates the group. Enclosing markup or end of data can occur immediately after a postfix separator (if dfdl:documentfinalSeparatorCanBeMissing is 'yes' then the postfix separator may be missing at the end of the datastream). This terminates the group. If the group terminates before all of its members have been parsed then any required members in the remainder of the group must be defaulted into the infoset. The entire group can have a zero-length representation, which is indicated by enclosing markup at the start of the group's content region. If another group member is expected and the next group member is a point of uncertainty then the identity of the next group member must be determined by resolving the point of uncertainty as described in section XXX. If another group member is expected but no group member is found in the data stream then it is a processing error. If another group member is expected but all group members have been parsed then it is a processing error. separatorPolicy="suppressedAtEnd" suppressAtEnd has the same rules as 'required' up to the last required member that does not have a default, then it has the same rules as 'suppressed' Open questions 1. If a group has separatorPolicy='required' and one of its optional members has a zero-length representation, and that member is allowed to have a zero-length representation, what should the parser do? A similar question arises for required, defaultable elements with a zero-length representation when they are based on a type with xs:minLength="0". Should the default value be used, or the empty string? 2. How should the occursXXX properties be applied when there are other ways to determine the number of occurences ( e.g. by counting separators )? 3. What algorithm should the parser use to decide whether to default a complex element or group ( when the element/group is a child of a separated group)? 4. How does unparsing work for separated groups in all of these scenarios? 4 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. .... 31/03: work is progressing 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 31/03: TK to document use cases for parsing 088 define semantics of choiceKind 'fixedLength' 31/03: TK to provide definition of calculable length. Investigate PL/I varchars and Cobol occurs dependingon. 089 Need to be able to define unsigned decimal and integer 31/03: MB to agree proposed solution 090 Semantics of separatorPolicy 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
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Alan Powell