- From: <paul.downey@bt.com>
- Date: Tue, 15 Jun 2004 15:44:27 +0100
- To: <distobj@acm.org>
- Cc: <www-ws-desc@w3.org>
Hi Mark! >> - finally it could be something completely out of band - my username >> denotes i'm a Gold Paying Customer, or first 100 messages each day >> are Gold, the remainder will be "bog-standard". I'm not sure what >> we could do here in the WSDL language beyond kick it out to an >> extension mechanism - this kind of interaction is outside of the >> domain of WSDL and in that scary land of "policy". > That's possible, but I hope it could be avoided; ideally, you don't > want a message to change meaning because something outside the message > - in this case, your Gold Paying status - changes. That introduces, > amoung other things, tighter temporal coupling between components; > consider what might happen if the message is processed 2 weeks later, > after your Gold Paying status has expired. Self-descriptive messaging > is your friend. 8-) fair point, and FWIW i wouldn't publish a service that worked like this. i guess that's the question - do we want to prevent the *possibility* of using out of message state to dispatch messages to an operation? >> So WSDL could describe the dispatching mechanism being used via binding >> specific mechanisms or extensions and i don't think we should do anything >> to prevent other to attempt to recognise (2) at the cost of not being able >> to describe all of (1) as well as other unforeseen dispatching mechanisms. > Sorry, I can't grok that. Sorry, i'll try and rephrase. I think there is a trade-off here: if WSDL attempts to prevent publishing ambiguous WSDL documents it does so at the risk of excluding unforeseen (or out-of-message) dispatching mechanisms. Paul
Received on Tuesday, 15 June 2004 10:46:50 UTC