- From: David E. Cleary <davec@progress.com>
- Date: Fri, 16 Nov 2001 11:19:17 -0500
- To: <qyz@clickmarks.com>, <xmlschema-dev@w3.org>
How about using Substitution Groups? Dave > -----Original Message----- > From: xmlschema-dev-request@w3.org > [mailto:xmlschema-dev-request@w3.org]On Behalf Of qyz@clickmarks.com > Sent: Friday, November 16, 2001 10:52 AM > To: xmlschema-dev@w3.org > Subject: Type Derivation Problems > > > > Hello, > > I can't figure out a way to extend a type which > has an empty content model to create a sub-type with a simple content > model. The problem is that the only way to declare a type with a simple > content model is to restrict a simple type? So I essentially need > multiple inheritance to do this :-( > > Example: > > <xs:complexType name="PropertyType"> > </xs:complexType> > > <xs:complexType name="BooleanPropertyType" > > <xs:simpleContent> > <xs:extension base="PropertyType"> > <xs:simpleType> > <xs:restriction base="xs:boolean"/> > </xs:simpleType> > </xs:extension> > </xs:simpleContent> > </xs:complexType> > > I'm trying to create BooleanPropertyType so that it is a sub-type of > PropertType, with a content model that allows only Boolean values. I know > the above is not valid XML Schema; is there any way to express this? It > seems to me that it should be allowed, because PropertyType has an empty > content model, so a boolean content model should be a valid extension? But > the type declaration doesn't let me specify: type="xs:boolean" (unlike an > element declaration which does allow that). So the only way to declare a > boolean content model is by restricting from "xs:boolean"? Which of > course means I can't derive from another type. > > Thanks for any help! > > Quinton > > >
Received on Friday, 16 November 2001 11:19:22 UTC