xml-dev - XML Schemas and extension

[Jeff Rafter <jeffrafter@earthlink.net>]

I know that we seemed to finish the "ref'ing vs. inlining" discussion and
all seemed pretty satisfied, but I was wondering how all of this fits into
type derivation when using extension.

I know that,

 "A complex type which extends another does so by having additional content
model particles at the end of the other definition's content model, or by
having additional attribute declarations, or both.

NOTE: This specification allows only appending, and not other kinds of
extensions. This decision simplifies application processing required to cast
instances from derived to base type. Future versions may allow more kinds of
extension, requiring more complex transformations to effect casting. "

I have read through the spec. and can't seem to come up with an answer to
the following, unless it fits into the above cited "future revision" caveat
: Can an element in be redeclared in a derived (by extension) complexType?

<complexType name="Foo">
  <element name="bar" type="int">
</complexType>

<complexType name="Foo2" base="Foo" derivedBy="extension">
  <element name="bar" type="int">
  <element name="bar2" type="int">
</complexType>

I apologize if there is an obvious answer in the specification that I am
missing or not comprehending.

Thanks,
Jeff Rafter
Defined Systems, Inc.