Re: [xml-dev] Performance Vs Size of XSD + Extension of restriction

["Pete Cordell" <petexmldev@tech-know-ware.com>]

----- Original Message From: "Sudheshna Iyer" > Pete, I didn't get what you 
are saying.
>
> I want my 'ChildType' to inherit the restrictions 'minLength' and 
> 'whiteSpace' from 'OrigType' and
> has its own 'maxLength'. So will the following info solve the requirements 
> relating to both syntax and semantics?
>
> <xs:simpleType name="OrigType">
> <xs:restriction base="xs:string">
> <xs:minLength value="1"/>
> <xs:maxLength value="20"/>
> <xs:whiteSpace value="collapse"/>
> </xs:restriction>
> </xs:simpleType>
>
> <xs:simpleType name="ChildType">
> <xs:restriction base="OrigType">
> <xs:maxLength value="40"/>
> </xs:restriction>
> </xs:simpleType>

As Michael said, restriction restricts what a type can accept.  So if you 
want to define types that only accept subsets of values that other types 
accept, then you have to start off defining the least restricted type and 
then progressively define each more restricted type from the previously 
(less) restricted type.

A type that accepts a string of 40 characters is less restricted than a 
string that accepts a string of 20 characters.  Therefore, in your case you 
have to define ChildType first.  Hence, using your names, you get:

<xs:simpleType name="ChildType">
<xs:restriction base="xs:string">
 <xs:minLength value="1"/>
 <xs:maxLength value="40"/>
 <xs:whiteSpace value="collapse"/>
</xs:restriction>
</xs:simpleType>

<xs:simpleType name="OrigType">
 <xs:restriction base="ChildType">
   <xs:maxLength value="20"/>
 </xs:restriction>
</xs:simpleType>

OrigType will inherit the restrictions of ChildType.  So OrigType is 
equivalent to:

<xs:simpleType name="OrigType">
 <xs:restriction base="ChildType">
   <xs:minLength value="1"/>
   <xs:maxLength value="20"/>
   <xs:whiteSpace value="collapse"/>
 </xs:restriction>
</xs:simpleType>

Note that I'm referring to order of derivation here, not the order they 
appear in the XSD file (which isn't) significant.  So the XSD file contents 
could equally be:

<xs:simpleType name="OrigType">
 <xs:restriction base="ChildType">
   <xs:maxLength value="20"/>
 </xs:restriction>
</xs:simpleType>

<xs:simpleType name="ChildType">
<xs:restriction base="xs:string">
 <xs:minLength value="1"/>
 <xs:maxLength value="40"/>
 <xs:whiteSpace value="collapse"/>
</xs:restriction>
</xs:simpleType>

HTH,

Pete.
--
=============================================
Pete Cordell
Tech-Know-Ware Ltd
for XML to C++ data binding visit
http://www.tech-know-ware.com/lmx
(or http://www.xml2cpp.com)
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