Re: [sca-assembly] Issue 116: Interface compatibility refers to input/outputtypes which is ambiguous when using WSDL 1.1

[Simon Nash <oasis@cjnash.com>]

Mike Edwards wrote:
> 
> Folks,
> 
> Comments inline
> 
> 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
> 
> Simon Nash <oasis@cjnash.com> wrote on 02/03/2009 10:24:04:
> 
>  > [image removed]
> <snip>
>  > > Outline --
>  > > 1) Use the WSDL 1.1 interface as the canonical interface language and
>  > > require that "sameness" be determined after the interfaces are 
> mapped to
>  > > WSDL 1.1.
>  >  >
>  > I don't think this is the right solution.  We don't require (and 
> shouldn't
>  > require) that all SCA interfaces must be mappable to WSDL.  The 
> requirement
>  > should be that the SCA interface types of the source and target interface
>  > define mappings that can be applied to the target interface to produce
>  > a representation of the target interface in the source interface 
> language.
>  >
> 
> I disagree.  I think that for remotable interfaces, it is right and 
> reasonable
> to require that all interface types map to WSDL.  If this is not done, 
> then you
> have a difficult n x n mapping table to construct - and worse, I think 
> it will
> be hard to know whether any particular binding can be used for that 
> remotable
> interface.
> 
> The requirement for mapping to WSDL allows a much simpler approach both to
> comparison of interfaces and also to the application of bindings.
> 
> For local interfaces, WSDL mapping should not be a requirement, but there,
> the restrictions on mapping of interfaces will need to be spelled out.
> 
The proposed text is for the wiring section.  Wiring applies to local
interfaces as well as remotable interfaces.  Any rules for wiring need
to apply to both local and remotable interfaces.  The text proposed
by Anish does not meet this requirement.

The question about whether all remotable interfaces are required to be
mappable to WSDL is a separate issue.  Currently, there is nothing in
the Assembly specification saying this and there is no open issue
concerning this.  A number of interface specifications are owned by
other TCs and IMO the Assembly specification should not impose this as
a requirement on all of those other TCs and the interface specifications
that they create.  Each interface specification should state whether or
not its remotable interfaces MUST be mappable to WSDL.  Having these
other specs require this and define the mapping to WSDL would be the
normal case.  For example, I think this mapping should be required and
defined for remotable Java interfaces.

I believe the alternative text that I have proposed is sufficient to
define wiring rules without the need to mention WSDL.  I am not sure
what the difficulty is with the application of bindings.  Please can
you give more details of this.

Requiring the compatibility test to be performed on mapped WSDL
doesn't work for some cases.  Consider the following examples:
1. A service uses interface.wsdl and a reference uses interface.java.
    In this case the service interface needs to be mapped from
    WSDL to Java and the compatibility test needs to be applied to
    the reference's Java interface and the WSDL->Java mapping of the
    service's interface.  It would not be valid to map the reference's
    interface from Java to WSDL using the Java->WSDL mapping and apply
    the compatibility test to this mapped interface and the service's
    interface, because the WSDL that will be used on the wire is the
    service's WSDL and not the generated Java->WSDL mapping of the
    reference.
2. A service uses interface.java and a reference uses interface.java.
    The compatibility test needs to be applied directly to these Java
    interfaces.  It would not be valid to to map them both to WSDL
    and apply the compatibility test to the generated WSDL, because
    of the false positives that could occur if different Java types
    map to the same WSDL type.

   Simon

> <snip>
>  >
>  >    Simon
>  >
>  > > -Anish
>  > > --
> 
> 
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