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RE: What Happens if 2 Inline Schemas Define the Same Element?

From: Ugo Corda <UCorda@SeeBeyond.com>
Date: Thu, 27 Jan 2005 13:09:48 -0800
Message-ID: <48BD8D0502C820438ECA5E27DC7AC9530134DFDA@MAIL05.stc.com>
To: "Arthur Ryman" <ryman@ca.ibm.com>
Cc: <www-ws-desc@w3.org>, <www-ws-desc-request@w3.org>
Arthur,
I would be inclined to reach the same conclusion, but I am usually
careful before discounting XSV's opinion (since it is being developed by
one of the "fathers" of XML Schema).
 
Ugo

	-----Original Message-----
	From: Arthur Ryman [mailto:ryman@ca.ibm.com] 
	Sent: Thursday, January 27, 2005 12:58 PM
	To: Ugo Corda
	Cc: www-ws-desc@w3.org; www-ws-desc-request@w3.org
	Subject: RE: What Happens if 2 Inline Schemas Define the Same
Element?
	
	

	Ugo, 
	
	Thx. Oxygen is giving the identical error message to Xerces.
They are referencing an "official" Schema error.[1] 
	
	I think we can sefely regard this as disallowed by Schema. We
don't have to check for equivalent definitions are let the later one
override the earlier one, etc. 
	
	[1] http://www.w3.org/TR/xmlschema-1/#sch-props-correct 
	
	Arthur Ryman,
	Rational Desktop Tools Development
	
	phone: +1-905-413-3077, TL 969-3077
	assistant: +1-905-413-2411, TL 969-2411
	fax: +1-905-413-4920, TL 969-4920
	mobile: +1-416-939-5063, text: 4169395063@fido.ca
	intranet: http://labweb.torolab.ibm.com/DRY6/ 
	
	
	
"Ugo Corda" <UCorda@SeeBeyond.com> 
Sent by: www-ws-desc-request@w3.org 

01/27/2005 03:32 PM 

To
Arthur Ryman/Toronto/IBM@IBMCA, <www-ws-desc@w3.org> 
cc
Subject
RE: What Happens if 2 Inline Schemas Define the Same Element?

	




	I did the same experiment, using an instance of the foo element
to be validated against foo.xsd. I tried 4 different schema validators.
The result are very similar except in one case: XSV. Here is a summary.
(Results were the same using the first version of foo-string.xsd with a
string, and the second version with an integer). 
	  
	XSV 28-1
	Warning: attempt to overwrite element
{http://www.ibm.com/foo}foo, ignored 
	XMLSpy 2005
	Error: element 'foo' is already declared 
	Stylus Studio 6.0
	Error: Global element'foo' declared more than once 
	Oxygen 5.1
	[Schema 1, sec 3.15.6] Error: sch-props-correct.2: A schema
cannot contain two global components with the same name; this schema
contains two occurrences of 'http://www.ibm.com/foo,foo' 
	There are two interesting results to point out: 
	  
	- XSV only generates a warning and validates with no errors (by
ignoring the second definition) 
	  
	- Oxygen gives a specific reference to Schema to justify its
error message 
	  
	Ugo 
	  
	-----Original Message-----
	From: www-ws-desc-request@w3.org
[mailto:www-ws-desc-request@w3.org] On Behalf Of Arthur Ryman
	Sent: Thursday, January 27, 2005 9:58 AM
	To: www-ws-desc@w3.org
	Subject: What Happens if 2 Inline Schemas Define the Same
Element? 
	
	
	We discussed this in the telecon today. I ran a little
experiment. Consider the master file: 
	
	<?xml version="1.0" encoding="UTF-8"?> 
	<schema xmlns="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://www.ibm.com/foo"
xmlns:tns="http://www.ibm.com/foo"> 
	       <include schemaLocation="foo-int.xsd"></include> 
	       <include schemaLocation="foo-string.xsd"></include> 
	</schema> 
	
	Where foo-int.xsd is: 
	
	<?xml version="1.0" encoding="UTF-8"?> 
	<schema xmlns="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://www.ibm.com/foo"
xmlns:tns="http://www.ibm.com/foo"> 
	       <element name="foo" type="int"></element> 
	</schema> 
	
	and foo-string.xsd is: 
	
	<?xml version="1.0" encoding="UTF-8"?> 
	<schema xmlns="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://www.ibm.com/foo"
xmlns:tns="http://www.ibm.com/foo"> 
	       <element name="foo" type="string"></element> 
	</schema> 
	
	I validated the master document and got an error: 
	 
	
	I then changed the definition of foo-string so that it was
identical to foo-int and got the same error message. 
	
	The moral of the story is that the XML schema validator just
looked at the QName and when that was duplicated it raised an error,
even of the defintions were identical. 
	
	Arthur Ryman,
	Rational Desktop Tools Development
	
	phone: +1-905-413-3077, TL 969-3077
	assistant: +1-905-413-2411, TL 969-2411
	fax: +1-905-413-4920, TL 969-4920
	mobile: +1-416-939-5063, text: 4169395063@fido.ca
	intranet: http://labweb.torolab.ibm.com/DRY6/ 
	




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Received on Thursday, 27 January 2005 21:10:25 GMT

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