For discussion on today's WG call. Action 205 was raised to ensure that
DFDL 'property types' are declared with XML Schema types that provide the
correct whitespace handling behaviour. The XML Schema types of the various
DFDL 'property types' are given in Part 1 of IBM's Schemas-for-DFDL.
The question boils down to whether a 'property type' should be an
xs:string or xs:token. The former preserves whitespace, the latter
normalizes and trims. (Note that xs:NMTOKEN is intended for attributes
only, so should not be used for DFDL properties as they can be expressed
in attribute or element forms.)
My recommendation is;
- Enumeration changed from xs:string to xs:token (reason: to match XSDL
more closely and trim leading/trailing whitespace)
- DFDL regular expression stays as xs:string (reason: regex may contain
literal white space)
- DFDL string literal changed from xs:string to xs:token (reason:
currently inconsistent with List of DFDL string literal)
- List of DFDL string literal stays as list of xs:token
- DFDL expression changed from xs:token to xs:string (reason: XPath may
contain non-ignorable whitespace)
Further:
- DFDL regular expression should not trim leading/trailing whitespace
- DFDL expression should trim leading whitespace before { and trailing
whitespace after }
- The enum of DFDL property names should be based on xs:token
The xs:unions for DFDL properties that can be two or more of the above may
need the member ordering reviewed. Example:
xsd:union
xsd:simpleType
xsd:simpleType
Usually in a union, the most restrictive member is placed first. With the
current types, the above has xs:token followed by xs:string, in accordance
with this practice. But the recommendation changes the types of both
members, so that the above becomes xs:string followed by xs:token.
Regards
Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848
From: Steve Hanson/UK/IBM
To: Suman Kalia/Toronto/IBM@IBMCA,
Cc: dfdl-wg@ogf.org, Mike Beckerle
Date: 27/03/2013 16:38
Subject: Re: [DFDL-WG] whitespace in DFDL annotations: right now
regex is xs:string, expression is xs:token
Suman
Looking at the XML schema-for-schemas, and doing a test in the XSD editor
in eclipse, XSD enumeration facets are modelled as xs:NMTOKEN and not
xs:string, like DFDL enums. XSD is perfectly happy to strip/collapse white
space. I think therefore that we should be doing the same for DFDL enum
properties. I don't see any harm in this - an enum is a contiguous
sequence of non-whitespace characters anyway, so any leading/trailing
whitespace is harmless.
Looks like XSD pattern facet is modelled as xs:string, preserving white
space. We should do the same for DFDL regex properties.
Regards
Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848
From: Steve Hanson/UK/IBM
To: Suman Kalia ,
Cc: dfdl-wg@ogf.org, dfdl-wg-bounces@ogf.org, Mike Beckerle
Date: 19/03/2013 17:41
Subject: Re: [DFDL-WG] whitespace in DFDL annotations: right now
regex is xs:string, expression is xs:token
The type called DFDLExpressionOrPatternOrNothing only makes sense for use
in one place - the element value of an assert or discriminator.
Regards
Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848
From: Suman Kalia
To: Mike Beckerle ,
Cc: dfdl-wg@ogf.org, dfdl-wg-bounces@ogf.org
Date: 19/03/2013 17:29
Subject: Re: [DFDL-WG] whitespace in DFDL annotations: right now
regex is xs:string, expression is xs:token
Sent by: dfdl-wg-bounces@ogf.org
Mike - I am not sure but my gut feeling is that it would start with the
most restrictive one first. i.e If empty string ( assuming it has
length facet 1) - would match Nothing , then xsd:token which is
restricted form of xs:string. I think you are going to get string with
white spaces collpsed ( xsd:token) if it not empty string. You can run
few tests to see the behavior..
Suman Kalia
IBM Canada Lab
WMB Toolkit Architect and Development Lead
Tel: 905-413-3923 T/L 313-3923
Email: kalia@ca.ibm.com
For info on Message broker
http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.ht...
From: Mike Beckerle
To: dfdl-wg@ogf.org,
Date: 03/19/2013 12:43 PM
Subject: [DFDL-WG] whitespace in DFDL annotations: right now regex
is xs:string, expression is xs:token
Sent by: dfdl-wg-bounces@ogf.org
This came up on the call. The schemas I have for DFDL annotations have
DFDLRegularExpression as an xs:string, and DFDLExpression as an xs:token.
I have no clue what a union of these types behaves like. But we have a
union called DFDLExpressionOrPatternOrNothing which is a 3-way union of
DFDLExpression, DFDLRegularExpression, and EmptyString (which is also
derived from xs:string but has length facet of 0 as well.
--
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology |
www.tresys.com
--
dfdl-wg mailing list
dfdl-wg@ogf.org
https://www.ogf.org/mailman/listinfo/dfdl-wg --
dfdl-wg mailing list
dfdl-wg@ogf.org
https://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
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
