[ASSEMBLY-88] Possible duplicate functionality offered by constrainingTypeand component - proposed resolution

[Mike Edwards <mike_edwards@uk.ibm.com>]

This is a proposal to resolve Issue
88.

Summary:
- remove constrainingType from the specification
- add an attribute to <component/>
called @constrained which is a boolean value with a default of "false"

- a <component/> with constrained=false
is just like a component today - no changes
- a <component/> with constrained=true
requires its implementation to follow rules similar to those for 
  constrainingType - namely:

"When the component using an implementation
has @constrained=true the implementation's component type 
MUST contain all the services, references
and properties explicitly declared by the component. The component’s 
references and services can have interfaces
specified and can have intents specified - the implementation's
service interfaces must be the same
or a superset and its reference interfaces must the the same or a subset,
while
any intents present in the componentType
must match those declared by the component.. An implementation MAY 
contain additional services, additional
optional references (multiplicity 0..1 or 0..n) and additional optional
properties
beyond those declared by the component,
but MUST NOT contain additional non-optional references 
(multiplicity 1..1 or 1..n) or additional
non-optional properties (a property with mustSupply=true). (and any such
references
will not be wired and any such properties
will not be configured by the component). Any services in the componentType
which are not also declared by the component
cannot be wired or promoted"

I believe that this allows a component
to control what its implementations MUST look like, which is the idea behind
constrainingType.

Detailed changes:



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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sca-assembly-1.1-spec-cd01-rev3+Issue88.doc