Re: [ubl-dev] SBS and Restricted Data Types

[stephen.green@systml.co.uk]

Hi Joe

For example, in the ...-XPath.xml subset definition file you would have

<Element name="Note" type="NoteType" prefix="cbc"
uri="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-1.0"

minOccurs="0" maxOccurs="1" text="">

         <Attribute name="languageID" use="optional" type="xsd:language"/>
      </Element>

which could be restricted to

<Element name="Note" type="NoteType" prefix="cbc"
uri="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-1.0"

minOccurs="1" maxOccurs="1" text="">

         <Attribute name="languageID" use="optional" type="xsd:language"/>
      </Element>

making the Note mandatory. This way the SBS mechanism allows restrictions
to cardinalities. A reminder that the resulting instances have to be valid
according to non-subset schemas too (in the SBS methodology) so only
restrictions and not extensions are likely to work.

For facets we decided not to create a mechanism for the committee spec
definitions which would restrict string content - this is to avoid
interoperability problems. If you are in a position to make use of facet
restriction of strings, say with patterns, beyond just restricting 
cardinality,
I'd suggest adapting the subset definition to this in a way which agrees
with your business partners but this is at your own discretion and outside of
scope for the SBS methodology (at present). If you wanted, you could perhaps
join the TC to get your method made public to help adoption and
interoperability. In the meantime how about an attribute added here

minOccurs="1" maxOccurs="1" text="" restriction-pattern="...">

I say 'restriction-pattern' because it has to obey XSD rules to still be
valid for XSD - the resulting string, say, has to be schema valid in the
document instance.

This would need an extension to the subset definition schemas (XSD and RNG).

How does this answer things? I'd consider whether allowing restrictions as
much as this doesn't create problems but it does make sense for implementers'
own subsets so maybe UBL's SBSC should consider it as a specified extansion.

As for how to create susbets in practical terms, along the SBS lines,
there are a few things to consider
+ how to model the subset (the Small Business SC simply pruned UBL schemas)
+ how to generate subset definitions (SBSC used scripting)
+ the need to create one's own uuid for each definition
+ how to publish (SBSC was created to create the definitions as UBL committee
   specifications and premanently publish them as such in
    http://docs.oasis-open.org/ubl/ for widest use and interoperablility)
+ how to associate the subset definitions (and maybe codelist files, etc)
   with the business process definitions and trading partner agreements
   (the SBS methodology only provides a mechanism for doing this with ebXML)

A further point is that restrictions of enumeration values are a special case.
Say you wanted to restrict a code - there is the Codelist Methodology for that
(in progress for UBL in general but version 0.3 is for UBL 1.0).
If you wanted to restrict an Identifier to add enumerations (as well one might
for an implementation, for example with a tax type ID) then I hope the same
codelist methodology could be used, perhaps creating one's own genericode
files for the identifiers and codelist association files to relate them to the
individual instances (document contexts) of the IDs in the documents.

All this relies somewhat on one's being in a position to create one's own
subset definitions, codelist genericode files and association files and to
associate them with the actual transaction arrangements and publish them.
The SBS especially provides all this somewhat to aid interoperability as
widely as possible and also to aid adoption where the above said position is
limited.

All the best

Stephen Green






Quoting Chiusano Joseph <chiusano_joseph@bah.com>:

> Please pardon me if this question has been asked before on this list (my
> searches indicated the contrary):
>
> In terms of the SBS, what is the best way (if any) to restrict data
> types of a UBL schema for an specific implementation? Whether it is a
> 1.0 or 2.0 schema does not matter for purposes of this question (at
> least I don't believe so).
>
> For example, what if one had a need to define an xsd:minOccurs or
> xsd:maxOccurs facet for an xsd:string data type, for their own
> implementation?
>
> Thanks,
> Joe
>
> Joseph Chiusano
> Associate
> Booz Allen Hamilton
>
> 700 13th St. NW, Suite 1100
> Washington, DC 20005
> O: 202-508-6514
> C: 202-251-0731
> Visit us online@ http://www.boozallen.com
> <blocked::http://www.boozallen.com/>
>
>