RE: Issue 019: WSDL Version Neutrality

> -----Original Message-----
> From: public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-
> request@w3.org] On Behalf Of Hugo Haas
> Sent: Monday, November 08, 2004 4:49 PM
> To: public-ws-addressing@w3.org
> Subject: Issue 019: WSDL Version Neutrality

> - the main issue with the action MIH comes from:
> 
>     An action may be explicitly or implicitly associated with the
>     corresponding WSDL definition. Section 3.3 below describes the
>     mechanisms of association.
> 
>   However, section 3.3 describes a WSDL 1.1-specific mechanism. If the
>   service has a WSDL 2.0 description, another mechanism needs to be
>   used, which is actually defined by the WSDL 2.0 specification[4].
> 
>   I would therefore propose that section 3.3 be introduced as a
>   mapping of a WSDL 1.1 description to an action URI, that we note
>   that for WSDL 2.0, the message reference component URI should be
>   used.
> 
>   This leaves us with an interesting issue: if there is a WSDL 1.1 and
>   WSDL 2.0 description available, which is the implicit value of the
>   action property? If in a year's time we release WSDL 2.1, what
>   happens? I believe that there is an implicit value of the action URI
>   recognized by the recipient of the addressing information for the
>   description of the service made in each version of WSDL. Those are
>   equivalent for the purpose of our specification.

Just because WSDL 2.0 has coined a URI that one could use as an action,
doesn't mean that we have to use it as our default.  You point out at
least one good reason not to - that having a URI creation algorithm that
is independent of the WSDL version is a good idea.  Identifying a
component and specifying an action are not necessarily the same thing.
The similarity of the results of the algorithm to generate unique action
URIs to WSDL component properties, which have the same characteristic,
is to some degree conincidental.

In any case, it's important to recognize the difference in use cases
between describing an existing Web Service and developing a Web Service
from scratch.  The defaulting mechanism is good for the latter case - it
gives you a complete set of action URIs quickly.  If you are describing
(say in WSDL 2.0) an existing service (say described in WSDL 1.1), you
already have a set of action URIs for that service, and you would have
to set those explicitly in the new WSDL if the default algorithm doesn't
match.

A single defaulting mechanism simplifies migration of a WSDL 1.1 service
+ WS-Addressing to WSDL 2.0 + WS-Addressing.  It also appears to me to
be simpler to adapt the existing WSDL 1.1 algorithm to accommodate WSDL
2.0 than the reverse.

And of course, this doesn't prevent one from using the WSDL 2.0
Component Designator URIs if one wants to specify them explicitly --
even for a WSDL 1.1 service, though one should be aware that the context
of that URI is "action" not "component identification".

Received on Monday, 15 November 2004 23:13:20 UTC