More on topic/filter metadata

[David Hull <dmh@tibco.com>]

(Haven't we already discussed this at least once?)

Actually, the SM endpoint is part of the Notify metadata, and you should be able to find out anything you need to know about the original subscription through the SM.

However, Sanjay's response jogs my memory (all the way back to five minutes ago, when I read the text none-too-carefully :-).  The current Topic metadata contains the particular topic that caused the match, which is not necessarily the same as the original topic expression.  This is fine, bit it's a little problematic for filter extensibility.  Shouldn't other filters be able to offer an analogous "reason you're getting this" datum with the Notify?  IMHO, we should

• Make it clear that other filtering mechanisms may cause metadata to appear in Notify messages.
• Provide a means of doing this both within Notify and without.  This argues for an omnibus "wsnt:NotifyMetadata" element, which could appear in either Notify or somewhere in a raw message.
  
• Move the description of the Topic metadata into the Topics spec

For now, I'll keep the current treatment of Topic, but I'd like to open an issue against this.