WSN2.46:
Should UseNotify be a policy utterance?
The SubscribeRequest message
currently contains a specialized <UseNotify> element indicating whether
the Producer should use the Notify message format described in section 3.1. The wrapper Notify message is
essentially a convenience and is not fundamental to the basic Subscribe/Notify
pattern. If it were not already in the BaseN specification, it could clearly be
added via policy mechanism. As
such, it should be treated as a pre-defined policy rather than a built-in
feature of Notification, just as topic, selector and precondition are now
treated as pre-defined filters.
Making this change would bring
WSN more closely in line with WSE and would also strengthen the extensibility
story concerning policy.
Specifications
Proposed
Recommendations
Remove the
<UseNotify> property from the SubscribeRequest message and define a
new subscription policy <UseRaw> as an optional child of the
<SubscriptionPolicy> element. The baseline behavior (in
absence of the <UseRaw> policy
element in the SubscribeRequest message) is to use the Notify wrapper.
Notes
Apr 14, 2005: David Hull
raised this issue on the mailing list and there was some email
discussion.
Apr
25, 2005 Conf Call: This issue was discussed and it was decided to log
it.
Status: Open
Date:
Apr
25, 2005
Contact:
David
Hull
Cross
Reference: