Are there really no common ways of doing versioning and extension yet?  =
Anybody know of any discussions on other lists regarding this topic.  =
Any help would be greatly appreciated.
thanks,
dean
  ----- Original Message ----- 
  From: Dean Hiller 
  To: www-xml-schema-comments@w... ; xmlschema-dev@w... 
  Sent: Thursday, June 03, 2004 7:19 AM
  Subject: versioning and extensibility


  I know the TAG has been defining versioning and extensions.  =
Definition of the two just to make sure I am on the right page...
  1. versioning - versioning the standard
  2. extensions - allowing companies to extend the schema for their =
proprietary stuff, not to be confused with schema extension element.

  Questions up from, but please read on for some context after this =
question....
  My basic question is how can extensioing and versioning be built into =
the schema to handle the new technologies of xml to object and =
vice-versa?  I have read some of the TAG findings, but they didn't seem =
to help me here much.  

  Context....
  More and more languages are creating objects that unmarshal/marshal =
themselves to/from xml via xsd's(castor, .NET, JAXB, etc).  You don't =
even have to do xml anymore.  It is great.  It is magically done for you =
until you find a bug in the library you are using :). Comparing this to =
languages as many would like to see these two things work well together =
in the face of versioning and extensibility.......

  Extensibility......
  I take the example of extensibility of a Java API.  It is very nice.  =
(Notice this is pretty standard)
  Lets say the standard is a Car object with the method setColor(Color =
c);
  I have my own CompanyXCar which is a Car.  My company has an extra =
feature called setSpeed(int i); so we add.

  A user of the standard would have to cast the Car to a CompanyXCar.  =
When my feature was finally excepted into the standard, the Car =
interface is changed such that it now has the method setSpeed(int i).  =
The user of the standard could now go back to using the complete =
standard without the cast to CompanyXCar.  I find this problem very hard =
to solve with xsd's.  More and more companies are using JAXB, Castor, =
and tools in .NET to create objects that unmarshal/marshall themselves =
to from the XML.  Many low level programmers that are not involved in =
the xsd standards are looking for this versioning and extensibility and =
ease of doing xml without having to do xml.

  Versioning
  This one is easier and was slightly addressed above.  The setSpeed =
method was added so 1.1 clients don't break and keep working with 1.2 =
servers.  The only time something breaks is when something is =
deprecated.  (Unless you are dealing with a standard that has listeners, =
but I won't go into detail on that as that is a more complicated topic.

  Should we possibly have all xsd created standards create =
non-extensible/non-versioned schemas and run it through some standard =
XSL that produces the standard versionable/extensible schema???  What is =
the cleanest way to do this?  Right now I happen to be using a standard =
that does not work well with what I explain above at all.  Notice this =
mistake would have been hard to make with a language api.  You almost =
have to specify that something is non-extensible, where in xsd's you =
have to remember to make each and every thing extensible instead of =
having the default be extensibility and forcing the standards body to =
make certain ones non-extendable.  Is there some kind of standard yet on =
how to make an xsd extensible/versionable????
  thanks for listening, and any comments, questions, are very =
appreciated,
  dean