Re: [sca-bpel] ISSUE 42: SBPEL3004 has an incorrect 'MAY'.

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

Mike Edwards wrote:
> 
> Danny,
> 
> Thanks for your investigative work.
> 
> I am happy with your proposal to remove SPBEL3004 as a normative 
> statement - but I would instead recommend replacing it with a non-normative
> explanatory sentence:
> 
> "In order to have an SCA multi-valued reference in a WS-BPEL process, a 
> variable is declared in the process which uses the 
> sca-bpel:multireference extension element"

+1 from me as well.

> 
> To deal with the queries which you raise:
> 
> - Since partnerLinkTypes aren't QNames, do we have to insist that the 
> partnerLinkType attribute of the sca-bpel:multiReference resolve to a 
> partnerLinkType declared in the same scope?
> *<mje>partnerLinkTypes are QNames, so I don't understand this comment. 
> The following is from the WS-BPEL spec:</mje>*
> <xsd:attribute name="partnerLinkType" type="xsd:QName" use="required" />
> 
> - Since we want the componentType derivation to be deterministic, how do 
> we determine whether it's 0..n or 1..n?
> *<mje>Doesn't a calculation similar to that in section 2.1.1 apply?  I 
> agree that we may need to add a parallel section for the 0..n and 1..n 
> cases..</mje>*

The extension sca-bpel:multiReference has an attribute called 
'multiplicity' with two possible values "0..n" or "1..n". A default 
("1..n") is also defined, if the attribute is absent. I think we need 
another statement or should modify 3006 to take into account the value 
of this attribute (or default).

-Anish
--

> 
> - What does . [SBPEL3007] "The type of the reference MUST be determined 
> by the partner link type and the partner role attributes of the 
> sca-bpel:multiReference extension element." mean?
> *<mje>The type of a BPEL reference is actually defined by the porttype 
> which applies to the reference, which is found via the partnerLinkType 
> and partnerRole*
> *- do you think that this needs spelling out further?</mje>*
> 
> - Does 3006 as above need to be tightened up to say that it's actually 
> not "a reference" but "THE reference pointed to by the partnerLinkType 
> attribute"?
> *<mje>I think that 3006 is correct - the partnerLinkType attribute does 
> not point at an SCA reference - it points at a partnerLinkType.*
> *The existence of a <reference/> in the componentType is derived from 
> the presence of a variable with the sca-bpel:multireference attribute,*
> *which I what 3006 says. </mje>*
> 
> 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
> 
> 
> From: 	Danny van der Rijn <dannyv@tibco.com>
> To: 	sca-bpel@lists.oasis-open.org
> Date: 	14/05/2009 17:26
> Subject: 	Re: [sca-bpel] ISSUE 42: SBPEL3004 has an incorrect 'MAY'.
> 
> 
> ------------------------------------------------------------------------
> 
> 
> 
> On today's call, Mike Edwards proposed:
> 
> Replace the text of SBPEL3004 with: "To represent an SCA multi-valued 
> reference a WS-BPEL process MUST use a variable which is declared with a 
> sca-bpel:multiReference extension element."
> 
> 
> 
> I had some concerns with the statement that were at least echoed by 
> Sanjay.  I was thinking that we lift the style of the text from SCA-BPEL 
> 2001/2:
> 
> [_SBPEL2001_ <#BPEL2001_T>] If a partner link specifies a 
> sca-bpel:service attribute, then a service MUST be generated for the 
> introspected component type. [_SBPEL2002_ <#BPEL2002_T>] The name of the 
> service MUST be the value of the sca-bpel:service attribute.
> 
> 
> As I was looking at what replacement text I might use for 3004 or Mike 
> Edwards statement, what I came across was actually the next sentences, 
> SBPEL 3005/6:
> When a variable declaration contains the sca-bpel:multiReference 
> extension, the type of the variable MUST be an element of 
> sca-bpel:serviceReferenceList.
> ...
> [_SBPEL3006_ <#BPEL3006_T>] The introspected component type MUST include 
> a reference with a multiplicity of either "0..n" or "1..n" that 
> corresponds to a variable with the sca-bpel:multiReference element.
> 
> I
> 
> I propose that we simply delete SBPEL 3004.
> 
> Furthermore, I think there are some issues lurking elsewhere in this 
> paragraph:
> 
> - Since partnerLinkTypes aren't QNames, do we have to insist that the 
> partnerLinkType attribute of the sca-bpel:multiReference resolve to a 
> partnerLinkType declared in the same scope?
> - Since we want the componentType derivation to be deterministic, how do 
> we determine whether it's 0..n or 1..n?
> - What does . [_SBPEL3007_ <#BPEL3007_T>] "The type of the reference 
> MUST be determined by the partner link type and the partner role 
> attributes of the sca-bpel:multiReference extension element." mean?
> - Does 3006 as above need to be tightened up to say that it's actually 
> not "a reference" but "THE reference pointed to by the partnerLinkType 
> attribute"?
> 
> 
> Michael Rowley wrote:
> _http://www.osoa.org/jira/browse/BPEL-42_
>  
> *From:* Najeeb Andrabi [_mailto:nandrabi@tibco.com_] *
> Sent:* Friday, May 08, 2009 2:06 PM*
> To:* _sca-bpel@lists.oasis-open.org_ <mailto:sca-bpel@lists.oasis-open.org>*
> Subject:* [sca-bpel] NEW ISSUE: SBPEL3004 has an incorrect 'MAY'.
>  
> Title: SBPEL3004 has an incorrect 'MAY'.
> 
> Target: SCA BPEL C&I PR 01
> 
> Description:
> SBPEL3004 states the following:
> "In a WS-BPEL process definition, a variable MAY include an 
> sca-bpel:multiReference extension element that declares that the 
> variable represents a multi-valued reference."
> 
> 'MAY' implies that some runtimes may choose not to implement 
> multi-valued reference using sca:bpel:multiReference extension element. 
> We want that the implementation of multi-valued reference using 
> sca-bpel:multiReference extension element be portable across different 
> runtimes.
>  
> Proposal:
> 
> Replace with --
> "In a WS-BPEL process definition, a variable can include an 
> sca-bpel:multiReference extension element that declares that the 
> variable represents a multi-valued reference."
>  
> 
> -Najeeb
>  
> 
> 
> 
> 
> ------------------------------------------------------------------------
> 
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