Re: [wsbpel] Issue 92 - 92.1 - Do not associate XML namespaces withextension IDs - Proposal For Vote

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

Since it is impossible to define an extension to BPEL without defining 
the extension's semantics I am having difficulty understanding the 
distinction you are trying to draw.

	Yaron

Francisco Curbera wrote:
> Your example is precisely the kind that I think is out of scope of this
> issue. The details of the engine behavior are not language extensions but
> engine specific policies. These are two very different things and I don't
> think we should be try to define a BPEL-specific policy mechanism.
> 
> Paco
> 
> 
> 
>                                                                                                                                   
> 
> 
>                       "Yaron Y. 
> Goland"                                                                                           
> 
> 
>                       <ygoland@bea.com>        To:       Francisco 
> Curbera/Watson/IBM@IBMUS                                      
> 
>                                                cc:       wsbpeltc 
> <wsbpel@lists.oasis-open.org>                                  
> 
>                       03/07/2005 09:40         Subject:  Re: [wsbpel] Issue 92 - 
> 92.1 - Do not associate XML namespaces with     
> 
>                       AM                        extension IDs - Proposal For 
> Vote                                                
> 
>                       Please respond 
> to                                                                                           
> 
> 
>                       
> ygoland                                                                                                     
> 
> 
>                                                                                                                                   
> 
> 
> 
> 
> 
> This approach is appropriate for defining a XML document instance. But
> we are defining a programming language that happens to use XML for its
> persistence format. Therefore our extensions will not and in fact cannot
> just be limited to extending the syntax of the language but also will
> extend the semantics of the language, including aspects of the semantics
> that are not even expressed in the syntax, such as changes or
> modifications to runtime behavior.
> 
> For example, if someone decided to actually define how the elephant (the
> notional BPEL message dispatcher we all work so hard not to talk about)
> works they might include an extension in their BPEL declaring that their
> BPEL program's logic depends on the person's interpretation of the
> elephant's functionality. In that case they would place an extension
> element in their BPEL process and nothing else, no elements, no
> attributes, nothing beyond the extension declaration itself. Because the
> thing their extension is changing is not the syntax of the BPEL process
> but the expectations of the BPEL processor's behavior.
> 
>              Yaron
> 
> Francisco Curbera wrote:
>  > I think the really important point is whether the <bpel:extensions>
> element
>  > should declare XML language extensions alone or also support something
>  > else. The intent has always been the former. So, call it "namespace" or
>  > "URI", the requirement is that it identifies an XML dialect being used in
>  > the definition of the process, and the way we identify XML dialects today
>  > is by providing the namespace of the schemas that define them. Anything
>  > else sounds like trying to expand the scope of issue 92.
>  >
>  > Paco
>  >
>  >
>  >
>  >
> 
>  >
>  >
>  >                       "Yaron Y.
>  > Goland"
> 
>  >
>  >
>  >                       <ygoland@bea.com>        To:       wsbpeltc
>  > <wsbpel@lists.oasis-open.org>
>  >
>  >
>  > cc:
> 
>  >
>  >                       02/28/2005 09:45         Subject:  [wsbpel] Issue
> 92 -
>  > 92.1 - Do not associate XML namespaces with
>  >
>  >                       PM                        extension IDs - Proposal
> For
>  > Vote
>  >
>  >                       Please respond
>  > to
> 
>  >
>  >
>  >
>  > ygoland
> 
>  >
>  >
>  >
> 
>  >
>  >
>  >
>  >
>  >
>  > The current proposal uses an attribute called "namespace" to identify
>  > the name of an extension. This is an unfortunate choice as it implies
>  > that the URI used to identify the extension is also the namespace URI of
>  > the attributes and elements associated with that extension. As I explain
>  > in <http://www.goland.org/Tech/extensions.htm>
>  > associating the extension URI and namespace URIs is not a good idea. It
>  > provides very little added benefit since it can only catch a tiny
>  > handful of typos and it makes re-use painful.
>  >
>  > I therefore propose that we name the attribute that will identify the
>  > extension "extensionURI" (based on a suggestion from Alex Yiu). This
>  > would make the syntax for the extension element into:
>  >
>  > <process>
>  >      …
>  >         <extensions> ?
>  >            <extension extensionURI=”anyURI” mustUnderstand=”yes|no”/> *
>  >         </extensions>
>  >      …
>  > </process>
>  >
>  >                          Yaron
>  >
>  >
>  >
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