ISSUE 17: Need to define Namespace handling for included Composites

[Scott Vorthmann <scottv@tibco.com>]

http://www.osoa.org/jira/browse/ASSEMBLY-17

On Nov 6, 2007, at 7:40 AM, Mike Edwards wrote:

>
> (Issue brought forward from OSOA)
>
> Line numbers all refer to the 1.0 SCA specifications published on  
> www.osoa.org
>
> RAISER:  Mike Edwards
>
> DESCRIPTION:
>
> Current definition of SCA <include.../> for Composites has two sets  
> of problems associated with it:
>
>    1. It does not respect XML namespace usage - which forces  
> consistent namespace usage across including / included composites,  
> which in practice hinders re-use
>    2. It moves artifact resolution to the includer - which does not  
> relate well to the Domain resolution mechanism described in the  
> Assembly specification
>
> An updated definition of <include../> is required to address these  
> issues.
>
> More detail:
> sca:include has creates two classes of problems:
>
> a) it does not respect XML namespace usage
>
> so that namespace prefices have to be used consistently and  
> repeatedly along
> an assembly hierarchy which is unreasonable and hinders re-use.
>
> b) it move artefact resolution to the includer
>
> so that in particular the domain include mechanism cannot be  
> expressed in
> sca:include.
>
> Raw proposal:
> -------------
>
> sca:include should be defined as include on the assembly graph, so  
> that artefact
> namespaces and artefact resolutions stays local to the includee.
>
> Example for a):
> ---------------
>
> <?xml version="1.0" encoding="UTF-8"?>
> <composite
>         name="includer"
>         xmlns="http://www.osoa.org/xmlns/sca/1.0";
>         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
>         xmlns:second="http://acme.org/stuff";
> >
>         <include name="second:includee"/>
>
> </composite>
>
> where
>
> <?xml version="1.0" encoding="UTF-8"?>
> <sca:composite
>         name="includee"
>         targetNamespace="http://acme.org/stuff";
>         xmlns:scabpel="http://www.osoa.org/xmlns/sca/bpel/0.9";
>         xmlns:sca="http://www.osoa.org/xmlns/sca/1.0";
>         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
>         xsi:schemaLocation="http://www.osoa.org/xmlns/sca/1.0
> ../schemas/sca-core.xsd ">
>
> <sca:component name="xyz">
>                 <scabpel:implementation.bpel process="myprocess"/>
>         </sca:component>
>
> </sca:composite >
>
> Breaks. For two reasons:
>
> 1. the sca: prefix wouldn't have meaning in the "includer" composite.
> 2. worse: the scabpel: prefix wouldn't have a meaning.
>
> The latter is more significant. While this could be fixed for bpel,  
> any other
> extension would lead to the same problem.
>
> It seems that textual include implies that namespaces have to be  
> consistently
> repreated all over the assembly hierarchy. E.g. suppose "Includee"  
> would look
> like this:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <sca:composite
>         name="includee"
>         targetNamespace="http://acme.org/stuff";
>         xmlns:scabpel="http://www.osoa.org/xmlns/sca/bpel/0.9";
>         xmlns:sca="http://www.osoa.org/xmlns/sca/1.0";
>         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
>
> xmlns:third="http://acme.org/stuff/third";
>         xmlns:fourth="http://acme.org/stuff/fourth";
>
> xsi:schemaLocation="http://www.osoa.org/xmlns/sca/1.0
> ../schemas/sca-core.xsd ">
>
> <sca:component name="xyz">
>                 <sca:implementation.composite  
> name="third:acomposite"/>
>         </sca:component>
>
> <sca:component name="xyz">
>                 <sca:implementation.composite  
> name="fourth:acomposite"/>
>         </sca:component>
>
> </sca:composite >
>
> That would require to repeat "third" and "fourth" consistently in  
> the "includer"
>
>
> PROPOSAL: None
>
>
> 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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