Re: Possible small RDDL enhancement

[Jonathan Borden <jborden@mediaone.net>]

Simon St.Laurent wrote:

>
> >  The bottom line will be demonstrations
> >and working implementations. I hope that people use RDDLClassLoader
(java)
> >but especially develop similar functionality for other languages.
>
> Defnitely!  I'm also pushing on a RDDL-like approach to data typing as
well
> as document typing; there seems to be some interest in the RELAX side of
> life, though I don't know that a change that substantial will happen at
> this point.

I am interested in hearing more about this ... if we are going to do typing
then it is essential that this be done in an interoperable fashion.

>
> > > I'm also really intrigued by the possibility of interacting
descriptions,
> > > where it becomes possible to talk about multiple namespaces in a given
> > > document in some coherent way.
> >
> >Something to mention is that 'xml:base' is very similar to 'rdf:about' in
> >the sense that setting the xml:base of a rddl:resource sets -what- the
> >rddl:resource is referencing. For example this might be a way to indicate
> >that the document is intended to describe these namespaces:
>
> Now if only I didn't consider xml:base an ugly interloper weakly tossed on
> top of XML 1.0, interfering with the infoset in especially weirdly
> complicated ways that require an understanding of which content is
relative
> URIs...  I'll stick with absolute URIs, thanks.

Actually I was thinking of the source or subject end of the link rather than
the destination or object end. Let me better explain what I am thinking:

Consider a RDDL document as a collection of arcs drawn from a namespace name
(a URI reference) to the various xlink:href URI references. The RDDL
"purpose" names the arc. The RDDL "nature" tells us about the URI the arc
points to.

That's fine if the RDDL document is _at_ the namespace URI, in which case
the namespace URI _is_ the base URI, the arcs are all drawn from this URI to
the other URIs.

Suppose we wish to draw an arc from some other URI to yet another URI. RDF u
ses the "rdf:about" attribute to name the source/subject URI. Using xml:base
we can also name the source URI. For example suppose we wish to make
statements about 4 different namespace names (in the RDDL case a statement
is a rddl:resource). You might set a different base URI (using xml:base) and
then even though all the XLink attributes are absolute URIs, the _source_ of
the arc will be the indicated base URI.


>
> >This is along the theme of "schema at namespace URI" except that various
> >schemata are thus *properties* of the namespace (which is a good thing
IMHO)
> >rather than a particular *equated* to the namespace (which would be a bad
> >thing IMHO). In this model a namespace is indeed like a class whose
> >properties are the resources the RDDL document contains.
>
> And the RDDL document can define which properties that class has.  That's
> some pretty amazing stuff you cooked up there!
>

What was cooked up is really mostly not from me. Save from the "RDDL"
acronym which *was* my idea, most of the ideas are from people on XML-DEV
starting including input from a broad spectrum of people. I have implemented
a bunch of stuff but hope that in retrospect even these implementations will
be just a small piece of what is to come. The real key to long term success
will be for many people to start implementing RDDL stuff in working code,
development of tools etc.

-Jonathan