W3C home > Mailing lists > Public > w3c-sgml-wg@w3.org > May 1997

Re: DTD Fragments and XML

From: Peter Flynn <pflynn@curia.ucc.ie>
Date: 03 May 1997 20:58:45 +0100
To: w3c-sgml-wg@w3.org
Message-id: <199705031958.UAA12146@curia.ucc.ie>
At 07:43 03/05/97 -0400, you wrote:
>Let's say that I am an XML user. I am happy with, say, the DocBook DTD,
>but need to insert a chemical formula in CML format. Or perhaps I want
>to insert something more mundane, some small element that does not have
>an expression in DocBook: 

Having annoyed the hell out of Eve, Terry, and other Davenporters while
fudging together the FAQ, I can synthesize with this one, as they say.
(You can see the result in the FAQ: DocBook with HTML forms and math :-)

>world. People will just remove the DOCTYPE line and depend on
>well-formedness. But having removed the DOCTYPE line, they have now
>taken all responsibility for the semantics of that document upon
>themselves. It can no longer be validated. 

Incidentally, I have assumed that WF documents, because they have no
DTD are, strictly speaking, not SGML. And you cannot use attributes
in WF documents, ever? (I may have missed something here: I need to have
this right for the FAQ).

>In my mind this is where the rubber meets the road. The rubber is
>generic markup, where the needs of the data are paramount: add an
>element if you need it. The road is the Internet where interoperability
>is paramount. It seems to me that in XML it is too hard to balance these
>factors.

I'm guessing but I don't think it is impossible to make XML versions
of popular and useful DTDs that are modular and easily modifiable.
But it would be way easier with some tools: in making HTML Pro it was 
easier because I used Near&Far to cut and paste chunks of many DTDs,
then tidy them up in the exported ASCII file. But this is not user-level
manipulability.

>I don't think that we can make it easy to combine DTDs without changing
>SGML. But maybe we can figure out a way to declare a namespace for
>elements: to "import" element names in a standard way. You wouldn't be
>able to validate the document but at least it would be clear what the
>elements MEAN.

This borders on AF for XML, and I don't see that in the workplan. My
$0.02 is that we are going to NEED, really need, a simple way to convey
to an XML browser "Hi, this is my DTD (or WF instance) and on this
occasion I have used <FOO> for a table, <BAR> for rows, and <BLORT>
for cells. Please carry on". Right now we can only interoperate at
the stylesheet level, and I don't see AFs in stylesheets (yet?)

///Peter
Received on Saturday, 3 May 1997 15:58:36 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:25:26 UTC