RE: Updated proposal for WS-Policy assertions

Nicely put. It addresses (pun not intended!) the points raised in today's meeting, but does so using a minimum of verbiage.
 
I'd change "can't" to "cannot" throughout, but that's a mere stylistic variation.
 
Tony Rogers
CA, Inc
Senior Architect, Development
tony.rogers@ca.com
co-chair UDDI TC at OASIS
co-chair WS-Desc WG at W3C

________________________________

From: public-ws-addressing-request@w3.org on behalf of Marc Hadley
Sent: Tue 14-Nov-06 10:40
To: public-ws-addressing@w3.org List
Subject: Updated proposal for WS-Policy assertions



The first part of the proposal is to remove the current 
wsaw:Anonymous WSDL marker. I think we might need to tweak the 
section describing the UsingAddressing marker to include the 
following text (modified to remove mentions of policy and anonymous) 
from the section describing the wsaw:Anonymous marker:

"A WSDL-based service description that includes the 
wsaw:UsingAddressing makes no assertion regarding a requirement or a 
constraint in the use of the anonymous URI in EPRs contained in 
messages sent to the endpoint."

The current text for UsingAddressing could be taken to imply that 
endpoints using it explicitly support anon and non-anon addresses but 
I think the intent is that UsingAddressing makes no claim about the 
types of address supported.

The second part of the proposal is to define three new elements for 
use in WS-Policy.

(i) <wsaw:AddressingRequired/> - the endpoint requires WS-Addressing, 
optionality can be conveyed using WS-Policy constructs.

(ii) <wsaw:AnonymousResponses/> (a child element of 
<wsaw:AddressingRequired>) - the endpoint can send replies using WS-A 
anonymous; the endpoint can't send to anon if not present.

(iii) <wsaw:NonAnonymousResponses/> (a child element of 
<wsaw:AddressingRequired>) - the endpoint can send replies using 
other addresses; the endpoint can't send to other addresses if not 
present (unless some other assertion adds a class of supported 
addresses).

Element (iii) is deliberately vague, its presence means that a non-
anon address might work but doesn't constrain what such an address 
might look like - a receiver can still reject an address that it 
doesn't grok or that requires a binding it doesn't support. The WG 
decided against specifying things like available response bindings so 
I think this is in line with that decision.

Here are some examples:

<wsp:Policy>
   <wsaw:AddressingRequired>
     <wsaw:AnonymousReplies/>
   </wsaw:AddressingRequired>
</wsp:Policy>

Means that addressing is required and only anonymous replies are
supported.

<wsp:Policy>
   <wsaw:AddressingRequired>
     <wsaw:NonAnonymousReplies/>
   </wsaw:AddressingRequired>
</wsp:Policy>

Means that addressing is required and only non-anonymous replies are
supported.

<wsp:Policy>
   <wsaw:AddressingRequired>
     <wsaw:AnonymousReplies/>
     <wsaw:NonAnonymousReplies/>
   </wsaw:AddressingRequired>
</wsp:Policy>

Means that addressing is required and both anonymous and non-anonymous
replies are supported.

<wsp:Policy>
   <wsaw:AddressingRequired/>
</wsp:Policy>

Wouldn't be too useful for anything other than a one-way message 
since neither anonymous nor non-anonymouse replies are supported.

<wsp:Policy>
   <wsaw:AddressingRequired>
     <wsaw:AnonymousReplies/>
     <wsfoo:AnonReplies/>
   </wsaw:AddressingRequired>
</wsp:Policy>

Means that addressing is required and that anon replies as defined by 
WS-Addr or WS-Foo are supported.

Marc.

---
Marc Hadley <marc.hadley at sun.com>
CTO Office, Sun Microsystems.