[DFDL-WG] Fw: DFDL occurs properties on global elements

[Steve Hanson]

Agreed on call that rather than invent different scoping rules for the 
DFDL occurs properties, we should let them appear on global elements in 
the usual way. On a global element they won't be validated as a consistent 
set though, that will only happen on local elements and element 
references.

Regards

Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh at uk.ibm.com
tel:+44-1962-815848
----- Forwarded by Steve Hanson/UK/IBM on 23/04/2013 19:20 -----

From:   Steve Hanson/UK/IBM
To:     dfdl-wg at ogf.org, 
Date:   17/04/2013 17:44
Subject:        DFDL occurs properties on global elements


Some more thoughts on this.

Even if 4 is changed to a schema definition error, the normal scoping 
rules would mean that an occurs property could still be picked up from a 
global element if either the global element use dfdl:ref which pulled in 
an occurs property, or if the element ref and it's schema were totally 
silent about an occurs property but a dfdl:format in the global element's 
schema wasn't silent so the global element picked up a default. As well as 
the SDE we'd need to make it clear that properties in 4 must not be picked 
up from the global element's scope.

----------------------------------------------

Errata 3.8 clarifies what action a DFDL processor should take when it 
encounters an object that explicitly carries properties that are not 
relevant to the object, as follows: 

1  Property not applicable to the object’s kind.
Schema definition error. Example is lengthKind on xs:sequence.
2       Property not applicable because of simple type. 
Warning. Example is calendarPatternKind on xs:string.
3       Property not applicable because of another DFDL property setting. 
        Warning. Example is binaryNumberRep when representation is text
4  Property not applicable because object is global. 
Warning (optional). Example is occursCountKind on a global xs:element.

I am starting to question whether 4 is the correct behaviour. I think this 
should be a schema definition error and not a warning because the property 
becomes applicable for an element reference that refers to that global 
element. It is a different situation from the other warning cases 2 & 3, 
where the test is made once scoping rules are applied, and the property is 
therefore not applicable. 

Thoughts?

Regards

Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh at uk.ibm.com
tel:+44-1962-815848
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

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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