- From: Dan Connolly <connolly@w3.org>
- Date: Tue, 05 Sep 2000 10:56:27 -0500
- To: Neil Archer <neil.archer@viewgate.com>
- CC: "XML Schema List (E-mail)" <xmlschema-dev@w3.org>
Neil Archer wrote:
>
> Hi,
>
> I have been trying to convert some DTD's we are using to the equivalent XML
> schema, but I cannot find a way to reflect the DTD OR which states that one
> or the other element only can be specified.
>
> i.e. if a document could contain an element A or an element B but not both
> the DTD would state something like:
>
> <!ELEMENT document((A|B))>
>
> Can anyone help by suggesting how I can show this in an XML schema?
Some folks around here have developed a tool that does
just that. From the documentation:
[[[
<!ELEMENT ROOT (A|B) >
<element name="ROOT">
<complexType content="elementOnly">
<choice>
<element ref="t:A">
<element ref="t:B">
</choice>
</complexType>
<element>
]]]
-- http://www.w3.org/2000/04/schema_hack/
> Please
> forgive me if there is an obvious answer to this but I'm new to using
> schemas and cant see a simple solution.
I think the answer is fairly straightforward, but your
experience shows that it is not obvious. May I ask which
of the specs you have managed to read? Have you
seen the primer?
http://www.w3.org/TR/xmlschema-0/
Did you use other materials
besides the specs to learn about XML Schemas?
e.g.
The XML Schema Specification in Context
by Rick Jelliffe, Academia Sinica Computing Centre
2000-02-24 draft only
compares XML Schema with XML DTDs, SGML DTDs,
HyTime, and perl regular expressions
http://www.ascc.net/~ricko/XMLSchemaInContext.html
Both the DTD->schema tool and the "in Context" discussion
document are linked from our page about XML Schema:
http://www.w3.org/XML/Schema
--
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Tuesday, 5 September 2000 11:57:21 UTC