RE: Issue 6413 - just thinking

Hi Katy,

> In theory, I could imagine this might be a possibility but, in practice, I can't think of a real example.  I'm concerned that we'd create an extra specification that would never be used outside the context of WS-T.

Many people appear to be saying that because they cannot think of a real example, therefore none exists, so therefore the WG should not be taking the fact that an example might exist into consideration.  While this "ostrich" thinking seems rather odd, especially when making such a fundamental decision concerning a specification, let's look at a real example:

Consider filtering in Eventing (the same reasoning would also work for Enumeration).
In the example, we have an endpoint that represents a machine (M).
We want to subscribe to events from M - but not all of them.  How do we do that?

The basic filtering mechanism in Eventing supports an XPath filter that will allow subscribers to define a subset of the events from M, based on the content of the event.

Now consider that M has many sub-resources (fragments).  For example, it has an operating system, it has hardware - which, in turn, is made up of a disk, a CPU, etc.  If M had a new filter type that composed with fragment access, subscribers would now be able to filter the events not only on the content of the event, but also on the sub-resource (fragment) that generated the event (i.e. only be sent events that were hardware related, for example).  This would be a very useful filter in many situations.

Basically anywhere there is a need to provide a filtering mechanism there is also a potential need to compose with fragment access.

> Worse still, a high proportion of use cases will require both specs so ultimately they will be read as a single specification.

Does this really mean "... a high proportion of IBM use cases ..."?  The industry at large has many implementations of Transfer as it stands, and there are also many other specifications that reference Transfer, so there appears no real justification for saying that, in general, a high proportion of use cases require fragment support - it just is not the case.

--Geoff


From: public-ws-resource-access-request@w3.org [mailto:public-ws-resource-access-request@w3.org] On Behalf Of Katy Warr
Sent: Wednesday, May 06, 2009 2:52 AM
To: Yves Lafon
Cc: Doug Davis; Geoff Bullen; public-ws-resource-access@w3.org
Subject: Re: Issue 6413 - just thinking


Yves

I guess that by 'more general' you mean that a separate fragment spec would be re-usable outside the context of WS-Transfer?   In theory, I could imagine this might be a possibility but, in practice, I can't think of a real example.  I'm concerned that we'd create an extra specification that would never be used outside the context of WS-T.  Worse still, a high proportion of use cases will require both specs so ultimately they will be read as a single specification.

That said, I fully understand the argument to keep the WS-T specification 'pure' for scenarios that don't implement fragments.  By placing the fragment text in the appendix (rather than the main body), we'll do exactly that.

Best regards
Katy

From:

Yves Lafon <ylafon@w3.org>

To:

Doug Davis <dug@us.ibm.com>

Cc:

Geoff Bullen <Geoff.Bullen@microsoft.com>, "public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>, public-ws-resource-access-request@w3.org

Date:

06/05/2009 08:52

Subject:

Re: Issue 6413 - just thinking


________________________________



On Tue, 5 May 2009, Doug Davis wrote:

> Geoff,
>  Allow me to turn it around for a sec... if the general premise of
> "strongly encouraging" is agreed to, and people do not "want a
> proliferation of fragment specs", then an obvious question (to me anyway)
> is: what's so bad about having it in Transfer?  I've heard (and understand

If the fragment definition is in Transfer, then it is quite likely
somebody else will define another "fragment spec" be it more general, or
attached to another spec. That's why having a standalone document for
fragment definition makes far more sense, it can be referred from
Transfer, but also from other specs that don't want to reuse Transfer.

As I said during the call, fragments definition are more linked to the
addressing or resources than the action on them (and for the record,
having the action distinct form the URI of the service is, well,
suboptimal. At least transfer allows action to be a set of properties, but
I digress ;) ).

--
Baroula que barouleras, au tiéu toujou t'entourneras.

        ~~Yves






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