Thursday, January 08, 2004
The good news is that finally, we've got a Web services spec that tackles the hard problem, interfaces. Yes, WS-Eventing is an application protocol (do we have to bind SOAP to it too?)
The bad news is that it continues the track record of abusing other application protocols (if indeed it's objective is to be used with them, which I can only assume is the case); the more that goes in the SOAP envelope, the less suitable it is for use with them, as it just duplicates what they already provide. Once again we see WS-Addressing as the culprit; wsa:Action and wsa:To exist to replace their counterparts in any underlying application protocol. For example, for HTTP, the counterparts of wsa:Action and wsa:To are the request method and request URI, respectively.
A point of frustration for me is that the semantics of subscription itself are largely uniform. What I mean is, wouldn't it be great if all Web services supported "subscribe"? So why not use HTTP like I've done, which is built for uniform semantics? Using a SOAP envelope with MONITOR and for the resultant notifications would be really sweet.