RE: Enumerated List management

You cannot expand the value space of an enumeration using extension. This does NOT work. Secondly the syntax you are using for describing schemas does not reflect the capabilities of W3C XML Schema so it is hard to agree or disagree with what you are proposing. 
 
As for whether xsi:type only applies to elements and not attributes, the answer is Yes. 
 
 
-----Original Message----- 
From: Danny Vint [mailto:dvint@mindspring.com] 
Sent: Fri 12/27/2002 12:22 PM 
To: xmlschema-dev@w3.org 
Cc: dvint@dvint.com 
Subject: Enumerated List management




 I have a question about enumerated lists and part of the hangup/issue is
 that my organization has implemented them in 2 different ways; one uses
 them as attribute content and the other uses them as element content. The
 difficult occurs when we want to allow the EXTENSION and RESTRICTION of our
 code lists. To get around the EXTENSION issue I think we have to define
 some extra types, something like this (note this isn't proper schema markup
 but I think you can follow it):
 
 I belive the only way to may extension as well as restriction to work is
 you will have to have something like this:
 
 <!-- ACORD Schema -->
 
 <simpleType name="GenderCodes" type="xsd:string">
 
 <simpletype name="Genders" type="GenderCodes">
 <enum value="male"/>
 <enum value="female"/>
 </simpleType>
 
 <!-- End ACORD Schema -->
 
 Now if you want to extend the list you have a "base" common type to go back
 to which means they are compatible types, but you are defining your own
 values (all restrictions off the wider "string" type, rather than the ACORD
 specific list).
 
 So Acme Company would do something like this for extension (Genders would
 now be part of the ACME namespace when used):
 
 <simpletype name="Genders" type="ACORD:GenderCodes">
 <enum value="male"/>
 <enum value="female"/>
 <enum value='other'/>
 </simpleType>
 
 or this for restriction:
 
 <simpletype name="Genders" type="ACORD:GenderCodes">
 <enum value="male"/>
 </simpleType>
 
 or this for both:
 
 <simpletype name="Genders" type="ACORD:GenderCodes">
 <enum value="male"/>
 <enum value='other'/>
 </simpleType>
 
 Note that restriction would really have two ways to be defined (with either
 of the two types in the ACORD schema) but I think we would want to specify
 that you use the method that allows both to occur so you don't shoot
 yourself in the foot later when you need to extend it as well.
 
 To use this I think you then need to use the xsi:type attribute to define
 which list you are actually using (xsi:type="ACME:Genders". Now this simple
 method I hate to say doesn't work (I believe) for attributes because of the
 need for the xsi:type attribute - I believe this can only be applied to
 element content and not attributes. Is this true?
 
 Does anyone have an alternate solution that works and provides validation
 of the values as well as allowing extension and restriction and hopefully
 works nicely with code generators so they would produce the same or a
 related class object.
 
 ..dan
 ---------------------------------------------------------------------------
 Danny Vint
 http://www.dvint.com

Received on Friday, 27 December 2002 15:35:22 UTC