Fwd: [ubl-dev] xsd for acc

["Stephen Green" <stephen.green@documentengineeringservices.com>]

Hi Danny

as far as I remember, when UBL 1 was in development
CCTS was only just maturing so not everyone agreed
on the exact details of how it would quite work at a
'schema' level. You have to understand that CCTS
does not include a concrete implementation layer -
it is essentially abstract and strictly implementation
neutral so anything about XML is strictly outside of
its scope. So how to turn it into XML and W3C XML
Schema in particular was completely up to the
implementer. Back  then the NDR was in development
too both within UBL and also in parallel (with much
overlap) within ATG. There was also the fact that there
was an EDI camp and an XML camp and some overlap
but a lot of antipathy too. So disagreement on how
to represent it in XML was not going to be easy. This
might be why there was a perceived need to use a
common set of schemas for the datatypes and also
for the CCTs as they were/are called - to try to minimise
disagreement as much as possible in view of the fact
CCTS itself couldn't solve all the XML implementation
disagreements. It was first thought that eventually the
datatypes would have to be derived in some way using
schema derivation from the CCTs. Then we realised
after already committing to including the CCTs as a
schema that the CCTS didn't really suggest this but
didn't forbid it exactly (depending on interpretation
and there were as many of those as there were
experts perhaps). The datatypes, we eventually agreed,
were only necessarily derived from CCTs in the 'model',
not necessarily literally in the XML schemas. So there
is no link needed in the actual schema between the
CCT and the conceptually 'derived' core datatypes -
this is already catered for in the CCTS where the
derivation is worked out. But the history of having
hand crafted such a CCT schema may have been a
factor in deciding to keep the CCT schema in the
package once UBL 1 got near standardisation. That's
history. The evolution of the ATG CCTS artefacts
was forged in part by both UBL and OAGIS work (with
overlap of participants between all three and some
deliberate meetings to maximize agreement) but
later there were obviously going to variations in ongoing
approaches. Agreement was as near as possible and
this was helped by agreement to use the exact same
schema files for these core dadatypes but it was
never all that important, all the same, to include a CCT
schema in any given package. As UBL 2  states
http://docs.oasis-open.org/ubl/os-UBL-2.0/UBL-2.0.html#d0e3395
it is there in UBL 2's package just to help customisers.
This isn't required by CCTS as CCTS doesn't even
mention XML let alone what to do about XML schemas.

Sorry for such a lengthy explanation: 'I didn't have
time to write a shorter one' :-)

All the best

Steve

--
Stephen D. Green

Partner
SystML, http://www.systml.co.uk
Tel: +44 (0) 117 9541606
Associate Director
Document Engineering Services
http://www.documentengineeringservices.com

http://www.biblegateway.com/passage/?search=matthew+22:37 .. and voice

2008/6/20 Danny Gaethofs <dgaethofs@yahoo.com>:
> Dear all,
> I was comparing UN/CEFACT with UBL and notice that in the UBL standard there is an XSD for the ACC but in the UN/CEFACT has only an xsd for the ABIE.
> Sorry not a  question I should ask here ! But still it remains strange perhaps that is because UBL is fully based on CCTS.
> kind regards,
> Danny
>
>
>



-- 
Stephen D. Green

Partner
SystML, http://www.systml.co.uk
Tel: +44 (0) 117 9541606
Associate Director
Document Engineering Services
http://www.documentengineeringservices.com

http://www.biblegateway.com/passage/?search=matthew+22:37 .. and voice