W3C home > Mailing lists > Public > www-xml-schema-comments@w3.org > October to December 2002

Re: What is the meaning of the import statement?

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 09 Nov 2002 10:46:38 +0000
To: "Milan Trninic" <mtrninic@galdosinc.com>
Cc: <Simon.Cox@csiro.au>, <www-xml-schema-comments@w3.org>, <xmlschema-dev@w3.org>
Message-ID: <f5bpttf58c1.fsf@erasmus.inf.ed.ac.uk>

"Milan Trninic" <mtrninic@galdosinc.com> writes:

> I was actually surprised by the simple answer I've got from you Simon that
> I've completelly forgot the initial problem I've started from. Slightly
> modified drawing is attached.
> In essence if I wa to create an application location schema, and try to
> import weather and transportation, the validation will fail.
> Once the base schema is imported through environment schema, it will not be
> imported again through transportation one. So a needed subset of the base
> schema will be ignored.
> If I use your solution Simon, that means that I have to analyze all schemas
> that I work with and find all dependencies on other schemas (namespaces) and
> create stubs for each of them.
> Now, this exactly is the reason I've mentioned scalability in one of the
> first emails. Once there are large "networks" of dependant schemas, it is
> not going to be easy for an application depveloper to analyze manually ALL
> schemas in the network that his schema depends on. Don't you think so?

This is a good point about a complex situation.  It suggests that a
helpful strategy for processors would be to operate the 'ignore
subsequent import' strategy _within single schema documents only_, so
that in your example the imports in the two second-level docs would
both be processed.  I'll take a look at what would be involved in
doing that for XSV.

Bottom line, however: there was no way the WG could envisage all the
usage patterns which would develop, so in 1.0 we adopted a minimalist
strategy.  We should return to this question for 1.1.

1.1 requirement candidate, in my view: Revisit schema location
strategy, at least wrt multiple <xs:import> for same NS in separate
schema documents.

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2002, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
 [mail really from me _always_ has this .sig -- mail without it is forged spam]
Received on Saturday, 9 November 2002 05:46:48 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Sunday, 6 December 2009 18:13:01 GMT