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This link may be of help
http://www.xfront.com/ZeroOneOrManyNamespaces.html
H
-----Original Message-----
From: Rex Brooks [mailto:rexb@starbourne.com]
Sent: 19 November 2002 19:47
To: Priscilla Walmsley; 'Peter Bergström'; xml-dev@lists.xml.org
Subject: RE: [xml-dev] Namespaces and XML Schema validation
Is it possible to have a number of schemata that are extensions of a
primary base schema within a single namespace? Or, do you have to
create serial namespaces to accommodate such a multi-part modular
language structure? Since that is exactly what we are doing with
Human Markup, it would helpful. We are currently in the 30-day public
comment period for our first spec so we are no where close to moving
on to the secondary base schema.
Thanks,
Rex
At 9:01 AM -0500 11/19/02, Priscilla Walmsley wrote:
>Hi Peter,
>
>Yes, you can only have one schema document per namespace, so you will
>be required to have a.xsd, b.xsd, etc.
>
>> PROBLEM 1
>>
>>
>> Example document:
>> <?xml version="1.0">
>> <a1 xsi:noNamespaceSchemaLocation="a.xsd"
>> xmlns:b="http:\\example.org\b\"
>> xmlns:c="http:\\example.org\c\">
>> <b:b1>This is element B1 from namespace B</b:b1>
>> <a2>This is the second element from schema a</a2>
>> <c:c1>This element is from namespace c</c:c1>
>> </a1>
>
>a.xsd would look something like this:
>
><xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema";
> xmlns:b="http:\\example.org\b\"
> xmlns:c="http:\\example.org\c\">
><xsd:import namespace="http:\\example.org\b\" schemaLocation="b.xsd"/>
><xsd:import namespace="http:\\example.org\c\" schemaLocation="c.xsd"/>
>
><xsd:element name="a1" type="a1Type"/>
><xsd:complexType name="a1Type">
> <xsd:sequence>
> <xsd:element ref="b:b1"/>
> <xsd:element name="a2" type="xsd:string"/>
> <xsd:element ref="c:c1"/>
> </xsd:sequence>
></xsd:complexType>
>
>and b.xsd and c.xsd would declare the b1 and c1 elements, globally.
>
>> PROBLEM 2
>>
>> Can I nest the namespaces in such an XML document, so that elements
>> from one namespace contains elements from other namespaces, and
>> still validate my XML
>> document against one or several XML Schemas?
>
>Yes, in this case you could have a.xsd import the b namespace, and
>b.xsd import the c namespace.
>
>> PROBLEM 3
>>
>> Can elements from one namespace occur several times in a hierarchy
>> where elements from other namespaces occur as fathers, i.e. true
>> nesting, and
>> still validate my XML document against one or several XML
>> Schemas? And how
>> would the XML Schemas that defines those namespaces look like?
>
>Yes, in that case a.xsd could import the b namespace, and b.xsd could
>import the a namespace. Same thing with b and c. (there is no rule
>that says "circular imports" are not allowed; in fact, they are
>necessary.)
>
>
>> PROBLEM 4
>>
>> Can I, using the example from my problem 3, enforce (through
>> validation)
>> that instances are created with exactly those elements, occuring
>> just one time each, with one single XML Schema?
>
>I assume you mean one single schema _document_ (since an XML Schema can
>be made up of more than one document, as we have seen above). No, you
>can't - the best you could do is put wildcards where you want the
>elements from other namespaces to go. Wildcards will allow you to
>constrain the namespace and number of elements that appear, but will
>not validate those elements without a schema document for that
>namespace.
>
>
>The examples from my XML Schema book are online at:
>
>http://www.datypic.com/books/DefXMLSchema/Examples.html
>
>I can't guarantee they're the exact same structure as your examples,
>but they might help.
>
>Hope that helps!
>Priscilla
>
>-----------------------------------------------------
>Priscilla Walmsley priscilla@walmsley.com
>Author, Definitive XML Schema (Prentice Hall PTR)
>-----------------------------------------------------
>
>
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--
Rex Brooks
Starbourne Communications Design
1361-A Addison, Berkeley, CA 94702 *510-849-2309 http://www.starbourne.com *
rexb@starbourne.com
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