Re: [sca-assembly] [ISSUE 157] Make support for constrainingTypean optional compliance point - Proposal

[Anish Karmarkar <Anish.Karmarkar@oracle.com>]

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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