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RE: Confirmation needed: block attribute

From: Priscilla Walmsley <pwalmsley@vitria.com>
Date: Thu, 14 Feb 2002 09:25:10 -0800
Message-ID: <C72C18E3B1C0D411B7B600D0B7A9208C824B1C@VT-SJC-MS3.vitria.com>
To: Eric van der Vlist <vdv@dyomedea.com>, xmlschema-dev@w3.org
Hi Eric,

> If I specify an empty string in the element definition and nothing in 
> the type definition, the actual value for the element will be "", the 
> actual value for the type definition will be the default one (thus 
> "restriction") and the result will still be "restriction". Can you 
> confirm this (since I find if rather confusing) ?

No, the empty set is different from the attribute being absent.  In this
case, there would be no disallowed substitutions.

> Now, if my type and element definitions are defined in two different 
> schemas with different default values, can you confirm that 
> each of them 
> use the default value of its own xs:schema ancestor if all the cases 
> (include, redefine and import)?

That is correct.

Hope that helps,
Priscilla
------------------------------------------------------------------
Priscilla Walmsley                          priscilla@walmsley.com
Vitria Technology                            http://www.vitria.com
Author, Definitive XML Schema                  (Prentice Hall PTR)
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> -----Original Message-----
> From: xmlschema-dev-request@w3.org
> [mailto:xmlschema-dev-request@w3.org]On Behalf Of Eric van der Vlist
> Sent: Tuesday, January 29, 2002 4:59 AM
> To: xmlschema-dev@w3.org
> Subject: Confirmation needed: block attribute
> 
> 
>  From my reading of the spec (and of the archives), it looks like the 
> substitution can be controlled at 4 different levels: the 
> xs:schema(s) 
> ancestor element(s) give(s) default value(s), the element declaration 
> can overide the default value and the type definition can 
> overide it too.
> 
> In the element and type declarations, the actual value is the 
> one in the 
>   block attribute if present and the default one if not.
> 
> Let's take first a simple example where the xs:schema 
> ancestor element 
> is the same for both the element and type definition and its value is 
> "restriction".
> 
> If I don't specify anything in the element and type definitions, the 
> actual value will be "restriction".
> 
> If I specify an empty string in the element definition and nothing in 
> the type definition, the actual value for the element will be "", the 
> actual value for the type definition will be the default one (thus 
> "restriction") and the result will still be "restriction". Can you 
> confirm this (since I find if rather confusing) ?
> 
> Now, if my type and element definitions are defined in two different 
> schemas with different default values, can you confirm that 
> each of them 
> use the default value of its own xs:schema ancestor if all the cases 
> (include, redefine and import)?
> 
> Thanks
> 
> Eric
> -- 
> Rendez-vous a Paris pour mes formations XML/XSLT.
>                                            
http://dyomedea.com/formation/
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Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
http://xsltunit.org      http://4xt.org           http://examplotron.org
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Received on Thursday, 14 February 2002 12:25:41 GMT

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