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Re: Web Services and Genericity

From: Francis McCabe <fgm@fla.fujitsu.com>
Date: Wed, 17 Jul 2002 13:26:47 -0700
Cc: www-ws-arch@w3.org
To: Miles Sabin <miles@milessabin.com>
Message-Id: <84519CED-99C3-11D6-A3D4-000393A3327C@fla.fujitsu.com>

+1 to that.
 From the POV of business logic the transport media is nearly always 
irrelevant or worse interfering. We should try to find an appropriate 
set of abstractions for the appropriate set of requirements.

The battle for hearts and minds is, it seems to me, what the right level 
of abstraction really is.

Frank


On Wednesday, July 17, 2002, at 06:52  AM, Miles Sabin wrote:

>
> This seems to relate to quite a few issues that've been discussed here
> recently (late vs. early binding, loose vs. weak coupling, and
> equivalence) so forgive me if this is a bit vague.
>
> It's noticeable that as we move up through the layers of XML/WS
> specifications from typing of individual messages, through
> specifications of individual multi-message operations, to
> specifications of multi-operation conversations, that the precise types
> of items from lower layers are being hardwired into the higher layers.
> For example, a WSDL port-type/operation hardwires in the types of its
> input and output messages; and in all the orchestration languages I've
> seen so far, specific WSDL port-type/operations are hardwired into the
> specification of the conversation.
>
> In the latter case, in particular, this seems to be particularly
> unfortunate, given that many business processes will be very similar at
> the level of orchestration, differing only in the types of the concrete
> service endpoints they apply to (which in turn might well only differ
> in message type) ... binding those lower layer types into the
> definition of the higher level orchestration makes it impossible to
> reuse the orchestration in different contexts.
>
> If this is the case then it might be desirable to take a leaf from the
> generic programming community's book, and consider defining higher
> layers relative to type-parameters rather than concrete types. WRT
> orchestration languages this would allow us to specify generic
> conversations schematically, effectively abstracting over broad classes
> of business processes, then instantiate at particular concrete
> port-types/operations to get a concrete conversation.
>
> Thoughts?
>
> Cheers,
>
>
> Miles
>
Received on Wednesday, 17 July 2002 16:26:51 GMT

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