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Re: how to constraint sinmpleTypes

From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
Date: 02 Feb 2001 12:07:33 +0000
To: Ayalew Kassahun <A.Kassahun@InfoRay.NL>
Cc: xmlschema-dev@w3.org, Michael Anderson <michael@research.canon.com.au>
Message-ID: <f5b8znp8f0a.fsf@cogsci.ed.ac.uk>
Ayalew Kassahun <A.Kassahun@InfoRay.NL> writes:

> Hi List, Mick,
> 
> None of the three scenarios are answer to my question. My question is that I
> want to specify in the schema that the allowed simple times (not only for
> age but for all simple types in my docs) are xsd:int, xsd:string or
> xsd:data. If there is anything which is of a simpleType then it must be one
> of the above three types.
> 
> I was think of in this lines:
> 
> In my schema ...
> 
> <xsd:simpleType name="mySimpleType">
>   <xsd:simpleType>
>     <xsd:union memberTypes="xsd:short xsd:integer xsd:double"/>
>   </xsd:simpleType>
> </xsd:simpleType>

Fine.

> then I want to use mySimpleType for whatever simple type ...
> 
> In my docs, for example:
> 
> <!-- age is a mySimpleType, it can be given as int, double or as string -->
> <xsd:element name="age">
>   <myNS:mySimpleType>
>   </xsd:simpleType>
> </xsd:element>

Use the 'type' attribute to give an element an existing type:

<xsd:element name="age" type="myNS:mySimpleType/>

> <!-- weight is a mySimpleType, it can only be a double -->
> <xsd:element name="weight">
>   <myNS:mySimpleType>
> 	<xsd:restriction base="xsd:double"/>
>   </xsd:simpleType>
> </xsd:element>

There is currently no way to derive a type from a union type by
subsetting its member types.  So the best you can do is

<xsd:element name="weight" type="xsd:double"/>

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/
Received on Friday, 2 February 2001 07:07:36 UTC

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