RE: Discussion Topics Re-Revisited

["Duane Nickull" <duane@xmlglobal.com>]

Hi Betty:

The example John gave was not meant to be a complete ebXML message,  only to
raise a point of conversation regarding each element having a way to point
back to a repository Data Element.   We would not do this in the XML
document instance, it would be done within the accompanying DTD or possibly
Schema.

I think that using the namespcaes such as your example is certainly alot
more robust.  We haven't yet decided an the actual syntactical (spelling?)
method yet.

>I don't think I understand the rationale for a unique ID for each
>element type and not the content.  By virtue of the unique name
>each element is unique.

What John was striving at is that each element will have a way to reference,
via a unique ID, an XML file in a repository which caontains all the
pertinant metadata about that element.

>If it is, I understand the rationale for this approach.  However,
>I would argue against using an XML ID for this methodology. Also,
>it wouldn't pass a parse for a unique ID.

Becuase the attribute "ID" has special meaning and constraints within the
XML 1.0 specification, I would not use that specific attribute name.  The
spec aslo states that the values of type ID must match the Name production
and a name must not appear more than once in an XML document as a value of
this type. ID values are used to  uniquely identify the elements which bear
them but were not intended to be used as a pointer.

>If I were looking for a <FRUIT> and I don't know what the fruit
>is but I have use the Unique ID in XPATH, I would get the first
>food - which may be spinach.
Unless you try:  //FRUIT/FOOD[5] or use some other XQL statement.
Nevertheless,  we would not use the ID as demonstrated.

The real question I think is "Should empty elements within the ebXML
infrastructure be required to always reference a repository item?"

I think that each DTD should be required to do so.  There may be a business
methodology rule whereby an item is required to be returned if it does not
contain a certain default base set of elements, regardless of whether they
contains text nodes.
The ebXML application which will call upon the repository functionality may
have rules to recognize this in order to avoid unnecessary querying.

My $0.02 worth

Duane Nickull
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President, Software Systems Architect
XML Global Technologies, Inc.
http://www.xmlglobal.com
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