RE: XML Implementation spec

[Bob Haugen <linkage@interaccess.com>]

Arofan,

Does subclassing in core components mean something different
from subclassing in an object model?

For example, if I am an object of the Buyer subclass and then
I want to switch to being a Seller, I would need to change my
class (which is not supported very well in most object-oriented
languages).  I would be better off being an object of the class
Party and adopting Roles of Buyer and Seller, which I can
change at will.

But maybe I am applying object-thinking, and you are not
using the concept "subclass" in an object-oriented sense?

Confusedly,
Bob Haugen

-----Original Message-----
From:	Arofan Gregory [SMTP:arofan.gregory@commerceone.com]
Sent:	Friday, May 26, 2000 4:08 PM
To:	'Bob Haugen'; 'ebxml-core@lists.oasis-open.org'
Subject:	RE: XML Implementation spec

Bob:

The point of subclassing is that the core information structure (the "Party"
information) would be the same whether the Party was acting as Buyer or
Seller. This way, it becomes possible to reuse the data structure of the
superclass in each of these otherwise disparate cases. That is the whole
point of subclassing - to allow re-use of the information in cases where
there is a different semantic associated with the same bits of data. So long
as the structure (at the level of the super-class) is common, the semantic
can be adjusted without making interoperability impossible.

Cheers,

Arofan Gregory

-----Original Message-----
From: Bob Haugen [mailto:linkage@interaccess.com]
Sent: Friday, May 26, 2000 1:26 PM
To: 'ebxml-core@lists.oasis-open.org'
Subject: RE: XML Implementation spec


Ernie Nishiseki wrote:
>Attached is a first draft of the XML Implementation Methodology
>specification.


Question:  in this document, Buyer and Seller are subclasses
of Party.  Is this the way the core component for Party will be
designed (I hadn't noticed it in other documents), or is that just 
an example of how to implement subclasses?

To put a point on the question, how could the same Party
be a Buyer in one exchange and a Seller in another,
if Buyer and Seller are subclasses?

Thanks,
Bob Haugen