From: Mike Edwards
[mailto:mike_edwards@uk.ibm.com]
Sent: 29 September 2009 08:53
To: OASIS Assembly
Subject: Re: [sca-assembly] [ISSUE 157] Make support for
constrainingType an optional compliance point - Proposal
Anish,
I take the view
that constrainingType is mostly about design time.
So to me, if a
composite happened to contain references to constrainingType, a runtime that
does not
support constrainingType should not reject that composite, since in the 99%
case,
the composite
is valid and should run perfectly successfully. I see little advantage in
rejecting
such
composites, other than to cause folk to rip out constrainingType markings from
composites
if they would
not run. This would not favour the use of constrainingType.
Basically, I
see this behaviour as treating constrainingType as an extension, where there is
no
requirement for
the runtime to understand the extension. I think that this is the right
approach.
Yours, Mike.
Strategist - Emerging Technologies, SCA & SDO.
Co Chair OASIS SCA Assembly TC.
IBM Hursley Park, Mail Point 146, Winchester, SO21 2JN, Great Britain.
Phone & FAX: +44-1962-818014 Mobile: +44-7802-467431
Email: mike_edwards@uk.ibm.com
From:
|
Anish
Karmarkar <Anish.Karmarkar@oracle.com>
|
To:
|
Mike
Edwards/UK/IBM@IBMGB
|
Cc:
|
OASIS
Assembly <sca-assembly@lists.oasis-open.org>
|
Date:
|
29/09/2009
07:19
|
Subject:
|
Re:
[sca-assembly] [ISSUE 157] Make support for constrainingType an optional
compliance point - Proposal
|
The issue [1] states:
"I'd like to assert that there may be many different ways to capture
the
top down design of a component or more importantly the design of a set
(or assembly) of components."
No doubt, top-down can be accomplished in variety of ways that go beyond
the SCA Assembly spec. But IIRC, the discussion around those ways has
always been about creating some kind of template that the assembler is
going to later edit to fill in details. I think there is a significant
difference between non-deployable/non-conformant templates and
"typing"
support in SCA runtimes. The current design of constrainingType provides
a way for the top-down designer to design a contract that is enforced by
the runtime. There is a significant value in that. I understand that
taking the optional route is sometimes (always?) a nice compromise in a
design-by-committee venue, but I think in this case, it significantly
reduces the value of the feature. In the same sense that making
recursive composition optional would undermine the value of that feature.
Even though I don't like the proposal, I do have a question about it:
Why does the proposal make it OK to ignore constrainingType when not
supported? I would have thought that it would be the opposite.
constrainingType is part of the contract, if the runtime doesn't support
it, it should reject the artifact that contains it rather than ignore it
and break the contract.
Thanks.
-Anish
--
[1] http://www.osoa.org/jira/browse/ASSEMBLY-157
Mike Edwards wrote:
>
> Folks,
>
> Here is a proposal to resolve Issue 157:
>
> http://www.oasis-open.org/apps/org/workgroup/sca-assembly/download.php/34342/sca-assembly-1.1-spec-cd03-Rev2%2BIssue157.pdf
>
> http://www.oasis-open.org/apps/org/workgroup/sca-assembly/download.php/34341/sca-assembly-1.1-spec-cd03-Rev2%2BIssue157.doc
>
>
>
>
> Yours, Mike.
>
> Strategist - Emerging Technologies, SCA & SDO.
> Co Chair OASIS SCA Assembly TC.
> IBM Hursley Park, Mail Point 146, Winchester, SO21 2JN, Great Britain.
> Phone & FAX: +44-1962-818014 Mobile: +44-7802-467431
> Email: mike_edwards@uk.ibm.com
>
>
>
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>
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>
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> IBM United Kingdom Limited - Registered in England and Wales with
number
> 741598.
> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6
3AU/
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>
>
>
>
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