OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help

ubl message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]

Subject: RE: [ubl] Discussion of substitution groups

A quick reminder - please reply only to the list so folks don't get duplicates.

From: Burnsmarty@aol.com [mailto:Burnsmarty@aol.com]
Sent: Tuesday, July 19, 2005 8:52 AM
To: CRAWFORD, Mark; ubl@lists.oasis-open.org
Subject: Re: [ubl] Discussion of substitution groups

Are you arguing with the desirability of:
    Substitution Groups?
The use of substitution groups complements the suggested use of unions in extending code lists in wd-ubl-cmsc-cmguidelines-1.0.html. I think that without substitution groups, this mechanism doesn't work.
When a user community needs to extend or restrict UBL for their own reasons, it is desirable to use a mechanism that forces the implementer to declare the extensions explicitly. Substitution groups does this because in order to validate an instance the definition of the substituting type must be present. Also, the designer of the base schemas ensures the type consistency of the substitutable information. 
I believe what is being proposed is not that substitution groups are necessarily used extensively within UBL schemas. What is being proposed is that the schemas be designed so that the substitution group mechanism can be utilized in extending the schemas in a clean and traceable way (that is the extensions are explicit in the referenced schema in the instance document). If substitution groups are used in UBL schemas they would only need to be used in the code list schemas themselves to allow an unconstrained or enumeration constrained set of values to be used in the code list.
What this requires of UBL primarily is the extensive use of global elements (the ones that are substitutable), and, code list schema design and usage that facilitates the extension mechanism.
In a message dated 7/19/2005 8:30:45 A.M. Eastern Daylight Time, MCRAWFORD@lmi.org writes:

Global seems to me
> to tie in very much with type
> oriented schemas

Actually, most arguments for local are centered around managing by types
rather than types and elements.

>and that in turn ties in with polymorhism (which
> requires the global elements as well
> as the global types).

I assume you mean named types since there are no such thing as global

>In other words
> it seems to me that the industry,
> where advocating global schemas
> (increasingly so, it seems) does
> seem to do so with features such
> as inheritance / polymorphic
> treatment of types strongly in mind,

I would be interested in any research related to polymorphic treatment
of types other than Arofan's paper since my google can't seem to find

> along with the growing tool and
> other standard support (XSLT 2, etc).

Once again, just because a tool supports a feature, that is not a
justifiable reason for using the feature.  Else we will just use <any>
and allow customizers free reign.


To unsubscribe from this mail list, you must leave the OASIS TC that
generates this mail.  You may a link to this group and all your TCs in OASIS


[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]