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RE: [RESEND] Derivation by restriction

From: Dare Obasanjo <dareo@microsoft.com>
Date: Tue, 2 Apr 2002 19:35:20 -0800
Message-ID: <8BD7226E07DDFF49AF5EF4030ACE0B7E05573C46@red-msg-06.redmond.corp.microsoft.com>
To: <Simon.Cox@csiro.au>, "Priya Lakshminarayanan" <priyal@microsoft.com>, <jeni@jenitennison.com>
Cc: <xmlschema-dev@w3.org>, <John.Herring@oracle.com>, <portele@interactive-instruments.de>
We've investigated this and believe it is a bug in MSXML. 

For now, I suggest using the XmlValidatingReader in the .NET framework
which currently correctly validates the target schemas. 

-- 
PITHY WORDS OF WISDOM 
People never like to discuss a lack of communication.
 
This posting is provided "AS IS" with no warranties, and confers no
rights. 
You assume all risk for your use. (c) 2002 Microsoft Corporation. All
rights reserved.



> -----Original Message-----
> From: Simon.Cox@csiro.au [mailto:Simon.Cox@csiro.au] 
> Sent: Sunday, March 24, 2002 11:03 PM
> To: Priya Lakshminarayanan; jeni@jenitennison.com; Dare Obasanjo
> Cc: xmlschema-dev@w3.org; John.Herring@oracle.com; 
> portele@interactive-instruments.de
> Subject: RE: [RESEND] Derivation by restriction
> 
> 
> Priya - thanks for attaching the old mail thread.  
> 
> This is directly relevant as I am working with the 
> initiative which triggered the issue 
> - Geography Markup Language (from OpenGIS Consortium).  
> 
> We are now ridding our schemas of cases where the type 
> of a substitution group member extended the type of the 
> substitution group head, while the container type was 
> derived by restriction.   
> 
> **However**, we are not out of the woods yet, in regards 
> to MSXML's rigorous implementation of derivation-by-restriction.  
> 
> In our schemas we have a /lot/ of cases following a general pattern:
> 
> 1.  Declare an element to act as head of substitition group;
> 2.  Declare non-abstract elements in the substitution group, 
> with a type derived from the type of the head by restriction; 
> 3.  Define a complex type which contains the abstract head 
> element; 4.  Define a restriction of the container which 
> specifies that 
> a particular concrete member element is present.  
> 
> This appears to be pretty much how substitution groups were 
> designed to be used.  
> 
> *** However, both the cases here run afowl of the MSXML 
> parser. *** ("Invalid particle derivation by restriction").  
> Is MSXML wrong here, or am I missing something else?
> 
> N.B. In the first case Member1Type is a restriction of Head1Type 
> by having a defined content model *** compared with an anyType ***.  
> In the second case Member2Type is a restriction of Head2Type 
> by restricting the cardinality of the content.  
> 
> 
> 
> ============
> 
> <?xml version="1.0" encoding="UTF-8"?>
> <schema targetNamespace="http://xmml.ned.dem.csiro.au/my"
> xmlns:my="http://xmml.ned.dem.csiro.au/my"
> xmlns="http://www.w3.org/2001/XMLSchema" 
> elementFormDefault="qualified" attributeFormDefault="unqualified">
>   <!-- -->
>   <element name="_Head1" abstract="true"/>
>   <!-- -->
>   <complexType name="Member1Type">
>     <sequence>
>       <element name="foo" type="string"/>
>     </sequence>
>   </complexType>
>   <!-- -->
>   <element name="Member1" type="my:Member1Type" 
> substitutionGroup="my:_Head1"/>
>   <!-- -->
>   <complexType name="ContainHead1Type" abstract="true">
>     <sequence>
>       <element ref="my:_Head1"/>
>     </sequence>
>   </complexType>
>   <!-- -->
>   <complexType name="ContainMember1Type">
>     <complexContent>
>       <restriction base="my:ContainHead1Type">
>         <sequence>
>           <element ref="my:Member1"/>
>         </sequence>
>       </restriction>
>     </complexContent>
>   </complexType>
> </schema>
> 
> ============
> 
> <?xml version="1.0" encoding="UTF-8"?>
> <schema targetNamespace="http://xmml.ned.dem.csiro.au/my"
> xmlns:my="http://xmml.ned.dem.csiro.au/my"
> xmlns="http://www.w3.org/2001/XMLSchema" 
> elementFormDefault="qualified" attributeFormDefault="unqualified">
>   <!-- -->
>   <complexType name="Head2Type">
>     <sequence>
>       <element name="foo" type="string" maxOccurs="unbounded"/>
>     </sequence>
>   </complexType>
>   <!-- -->
>   <element name="_Head2" type="my:Head2Type" abstract="true"/>
>   <!-- -->
>   <complexType name="Member2Type">
>     <complexContent>
>       <restriction base="my:Head2Type">
>         <sequence>
>           <element name="foo" type="string"/>
>         </sequence>
>       </restriction>
>     </complexContent>
>   </complexType>
>   <!-- -->
>   <element name="Member2" type="my:Member2Type" 
> substitutionGroup="my:_Head2"/>
>   <!-- -->
>   <complexType name="ContainHead2Type" abstract="true">
>     <sequence>
>       <element ref="my:_Head2"/>
>     </sequence>
>   </complexType>
>   <!-- -->
>   <complexType name="ContainMember2Type">
>     <complexContent>
>       <restriction base="my:ContainHead2Type">
>         <sequence>
>           <element ref="my:Member2"/>
>         </sequence>
>       </restriction>
>     </complexContent>
>   </complexType>
>   <!-- -->
> </schema>
> 
> =========
> _____
> [This mail represents part of a discussion of work in progress 
> and should not be used for any purpose without my permission.] 
> _____
> Simon.Cox@csiro.au  CSIRO Exploration & Mining
> 26 Dick Perry Avenue, Kensington WA 6151
> PO Box 1130, Bentley WA 6102  AUSTRALIA
> T: +61 (8) 6436 8639  F: +61 (8) 6436 8555  C: +61 (4) 0330 
> 2672 http://www.csiro.au/page.asp?type=resume&id=CoxSimon
> 
> > -----Original Message-----
> > From: Priya Lakshminarayanan [mailto:priyal@microsoft.com]
> > Sent: Tuesday, 19 March 2002 4:03 AM
> > To: Jeni Tennison; Dare Obasanjo
> > Cc: Xmlschema-Dev (E-mail)
> > Subject: RE: [RESEND] Derivation by restriction
> > 
> > 
> > Yes, the primer is in error. Attached is the mail thread 
> regarding the 
> > discussion. This was supposed to raised as an errata against the 
> > primer.
> > 
> > 
> > Thanks,
> > Priya
> > 
> > -----Original Message-----
> > From: Jeni Tennison [mailto:jeni@jenitennison.com]
> > Sent: Saturday, March 16, 2002 3:22 AM
> > To: Dare Obasanjo
> > Cc: Xmlschema-Dev (E-mail)
> > Subject: Re: [RESEND] Derivation by restriction
> > 
> > Hi Dare,
> > 
> > > NOTE: The above constraint on {type definition} 
> > > <http://www.w3.org/TR/xmlschema-1/#type_definition> means that in 
> > > deriving a type by restriction, any contained type 
> definitions must 
> > > themselves be explicitly derived by restriction from the 
> > > corresponding type definitions in the base definition.
> > >
> > > However this runs contrary to both the text in 'Essential 
> XML Quick 
> > > Reference' on XML Schema xs:restriction (p. 337) and the 
> example in 
> > > the XML Schema Primer[1] which imply that simply defining the 
> > > contained type again in a derived type without the contained type 
> > > deriving by restriction is allowable. XML Spy also validates both 
> > > schemas.
> > >
> > > So are we interpreting the recommendation correctly or not?
> > 
> > For what it's worth, I think that you are, and that the 
> Primer is in 
> > error.
> > 
> > Cheers,
> > 
> > Jeni
> > 
> > ---
> > Jeni Tennison
> > http://www.jenitennison.com/
> > 
> > 
> 
Received on Tuesday, 2 April 2002 22:35:37 GMT

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