- From: David Booth <dbooth@w3.org>
- Date: Tue, 10 Jun 2003 19:33:05 -0400
- To: Jacek Kopecky <jacek@systinet.com>
- Cc: WS-Description WG <www-ws-desc@w3.org>
Jacek,
Sorry I neglected to specifically address this in my previous message.
I am assuming in your example that you meant the services to use the same
targetNamespace. If so, it seems to me that (normally) you would already
have that kind of semantic equivalence, since the targetNamespace
indentifies the intended semantics[3]. However, in the end, it will always
depend on how the semantics of that particular service are defined, which
is outside of our scope to define.
For example:
<definitions targetNamespace="n" ...>
. . .
<service name="a" interface="i" targetResource="foo">
<port name="x">...</port>
</service>
</definitions>
<definitions targetNamespace="n" ...>
. . .
<service name="b" interface="i" targetResource="foo">
<port name="y">...</port>
</service>
</definitions>
Both services indicate the same targetNamespace ("n"), which is supposed to
unambiguously identify the semantics of the terms used in that
namespace[3]. Since service "a" and service "b" also indicate the same
WSDL interface ("i"), then it would be natural to make them semantically
equivalent, and doing so might be recommended "best practice". But since
the semantics of the service are beyond the scope of the WSDL
specification, they COULD be defined differently.
In other words, it may be a good idea to make them equivalent in most
cases, and that may be a good thing to recommend as a "best practice", but
since the semantics of a service are not defined by the WSDL specification,
I don't think it's something that the WSDL specification can meaningfully
require.
1. WSDL 1.2 draft:
http://dev.w3.org/cvsweb/~checkout~/2002/ws/desc/wsdl12/wsdl12.html#Service_resource_attribute
2. TAG Web Arch: http://www.w3.org/TR/webarch/#representations
3. targetNamespace:
http://dev.w3.org/cvsweb/~checkout~/2002/ws/desc/wsdl12/wsdl12.html#Definitions_XMLRep
4. Resource definition: http://www.ietf.org/rfc/rfc2396.txt
At 02:02 PM 6/10/2003 +0200, Jacek Kopecky wrote:
>David,
>
>I've fought on one telcon for the wording, whatever it ends up being, to
>include the following explanation (not necessarily in the same words):
>
>Different ports in two services with the same interface and the same
>targetResource are interchangeable in the same sense as different ports
>within one service with that interface and targetResource. I.e. from the
>point of view of the ports, it doesn't really matter if I write
>
><service name="a" interface="i" targetResource="foo">
> <port name="x">...</port>
></service>
><service name="b" interface="i" targetResource="foo">
> <port name="y">...</port>
></service>
>
>or
>
><service name="c" interface="i" targetResource="foo">
> <port name="x">...</port>
> <port name="y">...</port>
></service>
>
>It seemed to me that there was general agreement to this.
>
>Best regards,
>
> Jacek Kopecky
>
> Senior Architect
> Systinet Corporation
> http://www.systinet.com/
--
David Booth
W3C Fellow / Hewlett-Packard
Telephone: +1.617.253.1273
Received on Tuesday, 10 June 2003 19:33:10 UTC