Re: [wsbpel] Issue - 152 - Clarification of usage of "reference-scheme"attribute of "service-ref" element

["Yaron Y. Goland" <ygoland@bea.com>]

I'd like to propose a 3rd option - remove reference-scheme all together.

The definition of reference-scheme and how it should be used with 
various EPRs is ambiguous at best. I don't believe we can usefully 
reduce the ambiguity without also becoming a lot more specific than any 
of us want to in regards to EPRs.

But EPR's ambiguity means that the reference-scheme's utility as a 
generic handle onto EPRs is questionable. Therefore why don't we just 
get rid of the reference-scheme attribute? If an EPR needs some kind of 
higher level disambiguator then let a URI be defined as an attribute on 
the EPR's root element by the EPR author themselves. Let's keep BPEL out 
of it.

		Just a thought,

			Yaron

ws-bpel issues list editor wrote:

> 
> 
> This issue has been added to the wsbpel issue list. The issues list is 
> posted as a Technical Committee document to the OASIS WSBPEL TC pages 
> <http://www.oasis-open.org/apps/org/workgroup/wsbpel> on a regular 
> basis. The current edition, as a TC document, is the most recent version 
> of the document entitled ** in the "Issues" folder of the WSBPEL TC 
> document list 
> <http://www.oasis-open.org/apps/org/workgroup/wsbpel/documents.php> - 
> the next posting as a TC document will include this issue. The list 
> editor's working copy, which will normally include an issue when it is 
> announced, is available at this constant URL 
> <http://www.choreology.com/external/WS_BPEL_issues_list.html>.
> 
> 
>     Issue - 152 - Clarification of usage of "reference-scheme" attribute
>     of "service-ref" element
> 
> *Status:* open
> *Categories:* Syntax and validation <#category_syntax_and_validation>
> *Date added:* 27 Jul 2004
> *Submitter:* Alex Yiu <mailto:alex.yiu@oracle.com>
> *Date submitted:* 26 July 2004
> *Description:* This is a follow-up issue for Issue 34, which we passed 
> to introduce a "bpws:service-ref" element wrapper to contain details of 
> the EPR used by partnerLink. There was some discussion on how to use the 
> "reference-scheme" attribute of the "bpws:service-ref" wrapper element.
> 
> Here are some suggested usage:
> 
> (A) Keep it required as mentioned in original proposal of Issue 34:
> 
> The “bpws:service-ref” has a required attribute called 
> “reference-scheme” to denote the URI of the reference interpretation 
> scheme of service endpoint, which is the child element of 
> bpws:service-ref. Most likely, the URI of reference scheme will have the 
> same value for the namespace URI of the child element of 
> bpws:service-ref. But they are not necessarily the same.
> 
>     * When the BPEL container fails to interpret the combination of the
>       "reference-scheme" attribute and the content element OR just the
>       content element alone, a standard fault
>       "bpws:UnsupportedReference" must be thrown. 
> 
> (B) Make it optional:
> 
> The “bpws:service-ref” has an optional attribute called 
> “reference-scheme” to to denote the URI of the reference interpretation 
> scheme of service endpoint, which is the child element of bpws:service-ref.
> 
> Most likely, the URI of reference scheme and the namespace URI of the 
> child element of bpws:service-ref are not necessarily the same. 
> Typically, this optional attribute is used ONLY when the child element 
> of the “bpws:service-ref” is ambiguous by itself. The optional attribute 
> supplies further information to disambiguate the usage of the content.
> 
> Example: different treatments of wsdl:service element
> 
>     * If that attribute is not specified, use the namespace URI of the
>       content element within the wrapper to determine the reference
>       scheme of service endpoint.
> 
>     * if the attribute is specified, use the URI as the reference scheme
>       of service endpoint and treat the content element within the
>       wrapper accordingly.
>           o When the "reference-scheme" attribute is specified, the URI
>             value is MOST LIKELY different from the namespace URI of the
>             content element for EPR. 
>     * When the BPEL container fails to interpret the combination of the
>       "reference-scheme" attribute and the content element OR just the
>       content element alone, a standard fault
>       "bpws:UnsupportedReference" must be thrown. 
> 
> 
> *Submitter's proposal:*
> 
> I personally prefer (B) over (A).
> *Changes:* 27 Jul 2004 - new issue
> 
> To comment on this issue, please follow-up to this announcement on the 
> wsbpel@lists.oasis-open.org list (replying to this message should 
> automatically send your message to that list), or ensure the subject 
> line as you send it *starts* "Issue - 152 - [anything]" or is a reply to 
> such a message. If you want to formally propose a resolution, please 
> start the subject line "Issue - 152 - Proposed resolution", without any 
> Re: or similar.
> 
> To add a new issue, see the issues procedures document (but the address 
> for new issue submission is the sender of this announcement).
> 
> To unsubscribe from this mailing list (and be removed from the roster of 
> the OASIS TC), go to 
> http://www.oasis-open.org/apps/org/workgroup/wsbpel/members/leave_workgroup.php. 
> 
>