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RE: XML Schema 1.1 suggestion - allow defining of namespaces for namedelements or attributes

From: <noah_mendelsohn@us.ibm.com>
Date: Tue, 18 Jun 2002 23:25:16 -0400
To: "Lee Humphries" <Lee_Humphries@softworks.com.au>
Cc: asirv@webmethods.com, "Henry S. Thompson" <ht@cogsci.ed.ac.uk>, xmlschema-dev@w3.org
Message-ID: <OFF1C178E5.8C44DACD-ON85256BDD.00137BC8@lotus.com>

Well, schemas made a design decision that each schema document contributes 
declarations for one namespace.  This was done as a conscious tradeoff, as 
namespaces are often used to group definitions and declarations that are 
controlled by a given organization or group.  We could have done 
otherwise, but chose not to.  Note this is a feature of the representation 
of schemas in documents -- a different serialization might be different.

Anyway, a consequence of this is that you MUST use ref= to combine 
constructs from multiple namespaces.  No way around it.  Local 
declarations (which is what I think you mean when you say 'name' and 
'type') are scoped to their containing element, and therefore in the same 
namespace (I've oversimplified a bit, but the general sense of this 
explanation is right.) 

I suspect you're trying to avoid writing more than one schema document. 
When you're validating more than one namespace, you can't.   You can 
almost surely do what you need to do as long as you write one schema 
document per namespace, and use ref=.

------------------------------------------------------------------
Noah Mendelsohn                              Voice: 1-617-693-4036
IBM Corporation                                Fax: 1-617-693-8676
One Rogers Street
Cambridge, MA 02142
------------------------------------------------------------------







"Lee Humphries" <Lee_Humphries@softworks.com.au>
06/18/2002 06:28 PM

 
        To:     <noah_mendelsohn@us.ibm.com>, <asirv@webmethods.com>
        cc:     <xmlschema-dev@w3.org>, "Henry S. Thompson" <ht@cogsci.ed.ac.uk>
        Subject:        RE: XML Schema 1.1 suggestion - allow defining   of namespaces for 
namedelements or attributes


Hi Noah & Asir,

The situation's different when you 'name' and 'type' the element rather
than 'ref' to an existing element.  When you name and type the element
after importing the associated schema you lose the namespace as a
requirement of the newly defined element.   My objective was to get a
specific 'named and typed' element to also be required to exist in a
differing namespace from its parent, without refing (if there's such a
word).

Regards, Lee

-----Original Message-----
From: noah_mendelsohn@us.ibm.com [mailto:noah_mendelsohn@us.ibm.com]
Sent: Wednesday, 19 June 2002 8:01 AM
To: asirv@webmethods.com
Cc: Lee Humphries; xmlschema-dev@w3.org
Subject: RE: XML Schema 1.1 suggestion - allow defining of namespaces
for namedelements or attributes


Lee asked me about this question privately, and I proposed a solution.
Not 
sure whether it meets the need.  See attached:

------------------------------------------------------------------
Noah Mendelsohn                              Voice: 1-617-693-4036
IBM Corporation                                Fax: 1-617-693-8676
One Rogers Street
Cambridge, MA 02142
------------------------------------------------------------------




----- Forwarded by Noah Mendelsohn/Cambridge/IBM on 06/18/2002 06:16 PM 
-----


Noah Mendelsohn
06/18/2002 05:41 PM


        To:     "Lee Humphries" <Lee_Humphries@softworks.com.au>
        cc: 
        Subject:        RE: XML Schema 1.1 suggestion - allow defining
of namespaces for 
namedelements or attributes


I'm still confused why there's a problem.  I think you're saying you
have 
a wrapper elemen MessageBody which can have as its child a known set of 
elements, that happen to be in more than one namespace.  I don't want to

do all the typing, so here's an outline.  I think you can fill in the 
details.

<schema targetNamespace="NS1">
        <element name="a" ...>
        <element name="b" ...>
        <element name="c" ...>
</schema>

<schema targetNamespace="NS2">
        <element name="x" ...>
        <element name="y" ...>
        <element name="z" ...>
</schema>

<schema targetNamespace="www.myenvelope.com" 
                xmlns:ns1="NS1"
                xmlns:ns2="NS2">
        <element name="messageBody">
                <choice>
                        <element ref="ns1:a"/>
                        <element ref="ns1:b"/>
                        <element ref="ns1:c"/>
                        <element ref="ns2:x"/>
                        <element ref="ns2:y"/>
                        <element ref="ns2:z"/>
                </choice>
        </element>
</schema>

Doesn't this do what you need?  It accepts exactly the 6 elements, three

from each namespace.  You only use <any> when you don't know the element

names in advance.  The namespace is part of the element name.  Hope this

helps.


------------------------------------------------------------------
Noah Mendelsohn                              Voice: 1-617-693-4036
IBM Corporation                                Fax: 1-617-693-8676
One Rogers Street
Cambridge, MA 02142
------------------------------------------------------------------







"Asir S Vedamuthu" <asirv@webmethods.com>
Sent by: xmlschema-dev-request@w3.org
06/18/2002 07:53 AM
Please respond to asirv

 
        To:     <xmlschema-dev@w3.org>
        cc:     "Lee Humphries" <Lee_Humphries@softworks.com.au>, (bcc:
Noah 
Mendelsohn/Cambridge/IBM)
        Subject:        RE: XML Schema 1.1 suggestion - allow defining
of namespaces for named 
elements or attributes



Moving this to the schema dev list for discussion

Asir

-----Original Message-----
From: www-xml-schema-comments-request@w3.org
[mailto:www-xml-schema-comments-request@w3.org]On Behalf Of Asir S
Vedamuthu
Sent: Tuesday, June 18, 2002 7:38 AM
To: www-xml-schema-comments@w3.org
Cc: Lee Humphries
Subject: RE: XML Schema 1.1 suggestion - allow defining of namespaces
for named elements or attributes



Lee requested me to post this mail to comments list

-----Original Message-----
From: Lee Humphries [mailto:Lee_Humphries@softworks.com.au]
Sent: Sunday, June 16, 2002 6:56 PM
To: asirv@webmethods.com
Subject: RE: XML Schema 1.1 suggestion - allow defining of namespaces
for named elements or attributes


Hi Asir,

Sorry, obviously I didn't put in enough detail.

Here's a very simple example of what I'm looking to do (deliberately
sans namespace prefixes):
<Envelope xmlns="www.myenvelope.com">
                 <From>Me</From>
                 <To>You</To>
                 <MessageBody>
                                 <SomethingSpecific 
xmlns="www.mymessage.com">
                 </MessageBody>
</Envelope>

The thinking at the moment is that we'd define the contents of
<MessageBody> as xsd:any with a namespace="##other" for example.
What I'm dealing with though, is that I know in advance all the
different element names within <MessageBody> and I also know their
namespaces.  What I want to be able to do is to define both the element
name and the namespace, whereas at the moment I can only define one or
the other.
In other words I can have:
...
<xsd:element name="MessageBody">
                 <xsd:complexType>
                                 <xsd:choice>
                                                 <xsd:element 
name="SomethingSpecific"
type="SomethingSpecificType"/>
                                                 <xsd:element 
name="SomeError"
type="SomeErrorType"/>
                                 </xsd:choice>
                 </xsd:complexType>
</xsd:element>
...

or:

...
<xsd:element name="MessageBody">
                 <xsd:complexType>
                                 <xsd:sequence>
                                                 <xsd:any 
namespace="www.mymessage.com
www.myerror.com"/>
                                 </xsd:sequence>
                 </xsd:complexType>
</xsd:element>
...

But what I really want is:
...
<xsd:element name="MessageBody">
                 <xsd:complexType>
                                 <xsd:choice>
                                                 <xsd:element 
name="SomethingSpecific"
namespace="www.mymessage.com" type="SomethingSpecificType"/>
                                                 <xsd:element 
name="SomeError"
namespace="www.myerror.com" type="SomeErrorType"/>
                                 </xsd:choice>
                 </xsd:complexType>
</xsd:element>
...

Regards,
Lee Humphries
SOFTWORKS Australia
email: Lee_Humphries@softworks.com.au
phone: +61-7 3511 7000
Level 1, 33 Park Road, Milton, Queensland 4064, Australia

-----Original Message-----
From: Asir S Vedamuthu [mailto:asirv@webmethods.com]
Sent: Saturday, 15 June 2002 2:27 AM
To: Lee Humphries; W3C XML Schema Comments list
Subject: RE: XML Schema 1.1 suggestion - allow defining of namespaces
for named elements or attributes


Lee,

I do not understand your suggestion. May I request you to elaborate with
one
or two examples?

Asir

-----Original Message-----
From: www-xml-schema-comments-request@w3.org
[mailto:www-xml-schema-comments-request@w3.org]On Behalf Of Lee
Humphries (by way of "C. M. Sperberg-McQueen" <cmsmcq@acm.org>)
Sent: Friday, June 14, 2002 11:18 AM
To: W3C XML Schema Comments list
Subject: XML Schema 1.1 suggestion - allow defining of namespaces for
named elements or attributes






At the moment only the 'any' allows for its namespace to be defined.
This is a real pain in the neck when you can name the element (or
attribute) but you need to define it as existing in a different
namespace.
Adding the 'any' namespace declaration to 'element' and 'attribute'
would
go a long way to enabling full cross-namespace validation.

Lee Humphries
SOFTWORKS Australia
email: Lee_Humphries@softworks.com.au
Received on Tuesday, 18 June 2002 23:44:08 GMT

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