Re: [sca-bpel] Component Types in SCA

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

Mike Edwards wrote:
> 
> Najeeb,
> 
> I sympathise - it does get confusing.
> 
> I tried before now to get the name of "component type" changed to 
> "implementation info".  Names mean a lot, since
> they give people impressions of what they mean.
> 
> The real meaning of "component type" is really that it is a description 
> of the actual configurable aspects of an
> implementation (that is why "implementation info" would be more 
> appropriate).
> 

+1 to the name change.
Why don't we change it?
Names are important; a very large (if not all) number of readers get 
confused by this when they read the SCA specs the 1st time.

-Anish
--

> The component in a composite is a configuration of some implementation - 
> strictly, the component does not have
> a "type" - it is configuring a type.  Further to confuse things, it is 
> not necessary for a component to configure all of
> the configurable aspects of an implementation (eg the implementation may 
> have a configurable property, but if
> the property has a default value, then a using component can leave this 
> untouched).
> 
> For the composite to FORCE the component type of the implementation, the 
> concept of "constraining type" was
> introduced, to help in the case of top-down design where there is a 
> desire for the composite to dictate the "shape"
> of the implementation that it will (later) use. This is the equivalent 
> of the "component defining the type of the
> component" - but in reality it is defining the type of the 
> implementation (or at least its SCA-configurable form)
> 
> I hope this helps dispel some of the darkness.
> 
> 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
> 
> 
> *"Najeeb Andrabi" <nandrabi@tibco.com>*
> 
> 12/02/2008 20:11
> 
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> 	[sca-bpel] Component Types in SCA
> 
> 
> 	
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> 
> 
> 
> 
>  
>        I would like to make a comment about Component Types in SCA. This 
> is in context with defining a component type file for BPEL 
> implementations. I am curious about the fact that a component cannot 
> refer a component type: it has to infer what its type might be using 
> implementation.* element. I don’t understand the rationale behind this 
> approach. Component type defines the type of component so why it cannot 
> refer it. Approach of referring ones type is used everywhere in 
> specifications like XML schema, WSDL, BPEL etc. e.g. a schema element 
> can have a reference to complex type that defines the type of the element.
>  
>       My comment may be because of lack of understanding of SCA assembly 
> specification. But, from my understanding of the specification I think 
> we should allow components to refer their type.
>  
> --Najeeb
> 
> 
> 
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