[wsrp] ExtensionDescription

[Rich Thompson <richt2@us.ibm.com>]

While doing the pass to determine if
there where places other than eventing where an optional payload should
become mandatory if the related metadata specified a type for the payload,
I came across a tangentially related area in ExtensionDescription.

Currently ExtensionDescription (5.1.21)
have a required name & type with optional aliases, descriptions and
locations.

The issue I noticed is that while each
Extension should have a distinct QName for its name, it has the potential
to have different payloads depending on the location being extending. For
example, suppose I am defining a new extension foo:bar. Unless this is
a simple extension (e.g. extends just one structure or a set of structure
with the same info), I am likely to end up specifying a number of things:
 - extend ServiceDescription/RegistrationData
with metadata defining whether any optional parts of the foo:bar extension
are supported.
 - extend one or more request messages
with additional information the Consumer will supply to the Producer
 - extend one or more response
messages with additional information the Producer will supply the Consumer

Do others agree this would be the pattern
for more involved extensions?
If so, would people agree to moving
type and locations[] into a new structure which ExtensionDescription then
includes as an array?

Rich