[dsdl-discuss] XML Processing Model DSDL Use Case

Norm

Many thanks for taking on board the DSDL requirements as an acknowledged
use case for the XML Processing Model.

You asked the following perceptive questions:
>In particular, we're not sure how step 7 fits its results into the
right places and how the compound document is reassembled from all the
split and now transformed components.

These are the two key issues that we have been unable to resolve within
the DSDL committee so far. Step 7 seems the easiest to identify a
solution for. Where a specific namespace is invoked we would use NVDL
(ISO 19757-4) to separate it out for validation on its own, against the
schema for that namespace, ie MathML. At this point it is proposed that
the validation result would be sent for transformation and the result of
the transformation would be put back into the document tree at the point
the fragment was extracted for validation. Now this has an assumption in
it that when you hit a new namespace you start a different validation
process. Obviously this is not always going to be the case, so the
processing model needs some way of listing those namespaces for which
separate validation is required.

Having, in our example scenario named HTML, SVG and MathML as the tree
seperately validatable namespaces we would expect an occurrence of an
element in that namespace to invoke a separate validation/transformation
process and to record where in the originating stream that fragment had
been extracted. One thought was that you could perhaps replace the
extracted fragment with an Xinclude statement that would be activated
during the reconstruction phase. We have an acknowledged problem with
NVDL in that streams are not labelled adequately for this purpose. We
know this has to be fixed before we can manange validation fully. We
were hoping you would come up with the best solution :-)

You also asked: Do you perhaps have some simpler use cases that we could
build upon?

I feel that any simpler, two-way split, is too simplistic to test
properly test any proposed language. We deliberately chose a three-way
split to show that there may need to be multiple nested processes. Three
streams is the minimum you can use to demonstrate this adequately.

Martin Bryan
Convenor. ISO/IEC JTC1/SC34/WG1

-----Original Message-----
From: Norman Walsh [mailto:ndw@nwalsh.com]
Sent: 16 March 2006 19:49
To: Martin Bryan
Subject: XML Processing Model DSDL Use Case

Hi Martin,

The XProc WG has incorporated your use case into its requirements and
use cases document[1], but we're a little confused about how it's
supposed to work.

Although it claims to be a validation management use case, it
incorporates transformation as well and it isn't clear how the bits are
supposed to fit together.

In particular, we're not sure how step 7 fits its results into the right
places and how the compound document is reassembled from all the split
and now transformed components.

Can you shed any light on this use case? Do you perhaps have some
simpler use cases that we could build upon?

                                        Be seeing you,
                                          norm

[1]
http://www.w3.org/XML/XProc/docs/langreq.html#use-case-dsdl-validation

--
Norman Walsh <ndw@nwalsh.com> | People often say that this or that
http://nwalsh.com/            | person has not yet found himself. But
                              | the self is not something one finds, it
                              | is something one creates.--Thomas Szasz
--
DSDL members discussion list
To unsubscribe, please send a message with the
command  "unsubscribe" to dsdl-discuss-request@dsdl.org
(mailto:dsdl-discuss-request@dsdl.org?Subject=unsubscribe)