Title: Message
> Just to clarify my earlier description with
regards to your point below. The Consumer physically has access to the entire
markup fragment, so when business arrangements permit, the Consumer can make
any type of modifications to the markup. I guess one of the ideas we are
trying to capture in the Customized scenario and in WSIA in general is an
explicit well-defined interface that declares what are the customization
options (and, possibly, and also arguably, how to implement them). The
existence of such an interface (independently of the mechanism that's used to
describe it) is implicitly assumed in many of the discussions, mainly for
robustness reasons (the Producer is committed to support those adaptation
points one way or another along application changes). Naturally, the interface
can't capture all of the different customization options possible,
only those predicted and supported by the Producer. It is then up to the
business arrangements to define whether adaptations other than those defined
in the WSIA interface are allowed (in which case the Consumer can freely play
around with the markup), disallowed (in which case the Consumer can't do
anything with the markup), or anything in between (e.g., allowed after a
review by the Producer). I wouldn't suppose we - as a committee - can decide
between those options; we can only come up with the interfaces and assume the
business arrangements are taken care of.
Hope that makes sense.
Lastly, on the issue of
property driven adaptation vs. markup driven
adaptation, I wasn't present
at the smaller group discussion, so I may be
covering old ground.
However, I have significant concerns about the property
driven approach
that extend beyond back-compatibility. To me, the property
driven
approach implies that the producer must predict all of the changes that
a
consumer may want to make (since they are responsible for implementing
them). This may seem attractive from a Producer control standpoint
(which
I agree is an important issue), but I think it will have the effect
of limiting the
re-use of services. Certainly our experience to date
suggests that it is very
hard, if not impossible to predict the ways in
which Consumers may want to
adapt services and so I would argue we should
err on the side of flexibility.
