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OGF DFDL WG Call Minutes 2013-05-07
by Steve Hanson 07 May '13

07 May '13

Please find minutes from the above call on Redmine at http://redmine.ogf.org/dmsf_files/13076?download= Errata document is now at v013 here: http://redmine.ogf.org/dmsf_files/8104?download= Action 140 errata addendum at v001 here: http://redmine.ogf.org/dmsf_files/13017?download= Regards Steve Hanson Architect, IBM DFDL, Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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OGF DFDL WG Call Agenda 2013-05-07
by Steve Hanson 07 May '13

07 May '13

Please find agenda for call on Redmine at http://redmine.ogf.org/dmsf_files/13076?download= Regards Steve Hanson Architect, IBM Data Format Description Language (DFDL) Co-Chair, OGF DFDL Working Group IBM SWG, Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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implicit alignment of complex types
by Mike Beckerle 01 May '13

01 May '13

I believe the spec language is unclear here. It says: The 'implicit' alignment of complex elements and groups is the alignment of its child with the greatest alignment. This could be worded more clearly: The 'implicit' alignment of complex elements is the alignment of their model group. The 'implicit' alignment of a model group is the alignment of its child with the greatest alignment. -- Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com

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when does lengthKind='delimited' accept EOF instead of a terminator.
by Mike Beckerle 01 May '13

01 May '13

The exact semantics of lengthKind='delimited' are a little bit unclear to me. Are there situations where we accept end-of-data as a substitute for finding a delimiter? Consider this: <element name="foo" type="xs:string" dfdl:lengthKind="delimited" dfdl:initiator="[START]" dfdl:terminator="[END]"/> I think this string should always cause a processing error: "[START] some data ". That is, the [END] terminator is not present, instead one runs out of data. So what exactly are the situations where delimited length kind will not find a delimiter, hit end-of-data, and be ok with it? I understand that hitting end-of-data might cause a backtrack for resolving points of uncertainty, but is there ever a case where running out of data is accepted as a substitute for finding a delimiter? (I am hoping the answer here is no, but I am asking because I am not certain.) -- Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com

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passing parameters to DFDL?
by Garriss Jr., James P. 29 Apr '13

29 Apr '13

XSLT has an ability to pass an external value to a parameter within the stylesheet, using <xsl:param>. Does DFDL have a similar capability? Does dfdl:defineVariable allow this? TIA

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OGF DFDL WG Call 2013-04-30 - cancelled
by Steve Hanson 28 Apr '13

28 Apr '13

Sorry have to cancel the call as I am at an IBM conference in Las Vegas and the time doesn't work. Regards Steve Hanson Architect, IBM DFDL Co-Chair, OGF DFDL Working Group Hursley, UK smh(a)uk.ibm.com tel:+44-1962-815848

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Cancelled: OGF DFDL WG Call
by Steve Hanson 28 Apr '13

28 Apr '13

Steve is at IBM IMPACT conference

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AUTO: Sunil Dandamudi is out of the office (returning 04/29/2013)
by Sunil Dandamudi 25 Apr '13

25 Apr '13

I am out of the office until 04/29/2013. Note: This is an automated response to your message "dfdl-wg Digest, Vol 82, Issue 17" sent on 04/25/2013 8:00:01. This is the only notification you will receive while this person is away.

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MBTK and Daffodil - Intentioning Violating Property Scoping Rules?
by Garriss Jr., James P. 25 Apr '13

25 Apr '13

(Emotions are hard to convey in email; please trust me when I say that I am writing this email with kindness and friendliness!) In section 8 it says, "The dfdl:format annotation on the top level xs:schema declaration provides defaults for the DFDL representation properties at every DFDL-annotatable component contained in the schema document. They do not apply to any components in any included or imported schema document (these may have their own defaults)." If I understand this, it means that when properties are defined using <dfdl:format> in one DFDL schema file, they are out of scope for any other DFDL schema file. So if schema A defines some properties and includes schema B, the properties are out of scope in schema B. Similarly, if schema A includes schema B and schema B defines some properties, the properties are out of scope in schema A. Is that right? I think so, and I have empirically confirmed this in both tools. Ok, so you know where this going, right? Why does the following line work? <xsd:import namespace="http://www.ibm.com/dfdl/GeneralPurposeFormat" schemaLocation="IBMdefined/GeneralPurposeFormat.xsd"/> According to the spec, it shouldn't. Yet both tools support it. But if you make any changes to the GeneralPurposeFormat, it breaks. You can't rename it. You can't put it in a different folder. Etc. Here's what I suspect: Both MBTK and Daffodil hard-coded this as an undocumented exception to the rule. I think you want to have your cake (properties are out of scope) and eat it, too (except when we want them to be in scope because repeating all the properties in every DFDL file is a pain). If I'm wrong, just let me know. It's entirely possible that I don't really understand what's going here. But if I'm right, then you guys should not do this. * If the spec makes sense, then you should follow the spec. * If the spec doesn't make sense, then you should change the spec. * If the spec needs an exception to the rule for this one case, then add an exception and follow it. To intentionally break the spec in an undocumented fashion seems wrong.

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empty sequences
by Mike Beckerle 24 Apr '13

24 Apr '13

This section of the spec seems wrong: 14.1 Empty Sequences A sequence having no children is syntactically legal in DFDL. In the data stream, such a sequence can have non-zero length LeftFraming and RightFraming regions, but the SequenceContent region in between must be empty. It is a processing error if the SequenceContent region of an empty sequence has non-zero length when parsing. XML schema does not define an empty sequence that is the content model of a complex type definition as effective content so any DFDL annotations on such a construct would be ignored. It is a schema definition error if the empty sequence is the content model of a complex type, or if a complex type has nothing in its content model at all. This seems like it is both legal and useful: <complexType name="headerRowType"> <sequence dfdl:initiator="name%WSP+;address%WSP+;phone" dfdl:terminator="%NL"/> </complexType> So the statement, DFDL annotations on such a construct would be ignored, is not right. And also a complexType sequence might actually have content via dfdl:hiddenGroupRef. <complexType name="hiddenGroupType"> <sequence dfdl:hiddenGroupRef="myHiddenGroup"/> </complexType> So the statement that the region in-between left and right framing must be empty is also not right. Comments? -- Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com

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