Re: [wsbpel] Issue 305 proposal for discussion

Mark,

Thanks for the proposal. 

I have taken a look of the proposal. 

I have uploaded a reviewed version of your proposal to OASIS website: 

http://www.oasis-open.org/apps/org/workgroup/wsbpel/document.php?document_id=19449

Most of my review changes are relatively minor rewording for clarity,
except the following two which have a real semantics changes:

[a] Consistent LValue Restriction:

  
There
is no requirement that <query>
return lvalues. When the <query> used in a variable variant
to-spec or the
<query> of <propertyAlias> used in a property variant
to-spec does
not return an lvalue, an attempt to assign to such a to-spec MUST fail
with a bpel:selectionFailure
(as defined in
section 8.4. Assignment).
Multiple nodes may be selected with this <propertyAlias> feature.
However,
those selections may be then filtered in the rest of expression and
result in
one node returned.

[b] Opaque from-spec and to-spec: 

In your original
proposal, you introduced two new forms of opaque of from-spec and
to-spec. Those two original suggestions do not provide any new
additional values, when compared with the opaque from-spec and to-spec
based on expression. I would suggest we should either choose not to add
new opaque forms or add opaque forms with different level of
abstraction. For example: 

-----------------------------

·       
<from>
element incorporating a query:

<from variable="NCName"
part="NCName"?>

   <query
queryLanguage="anyURI"? opaque="yes" />

</from>

 

-----------------------------

-----------------------------

·       
<to>
element incorporating a query:

<to variable="NCName"
part="NCName"?>

   <query
queryLanguage="anyURI"? opaque="yes" />

</to>

 

-----------------------------

These two forms of from-spec and to-specs are edited in the reviewed
proposal that I have uploaded.

Thanks!

Regards,

Alex Yiu

Mark Ford wrote:

  
  
  
  

  
I have prepared the
changes for Issue 305 and added them to
the TC documents page:

  
 

  
Here are the links to the
document:

  
 

  
View Document
Details:

  
http://www.oasis-open.org/apps/org/workgroup/wsbpel/document.php?document_id=19447

  
 

  
Download
Document:  

  
http://www.oasis-open.org/apps/org/workgroup/wsbpel/download.php/19447/Issue-305-wsbpel-specification-draft.doc

  
 

  
 

  
Summary of changes:

  
1. restored the
<query> option to the first from-spec
and to-spec.

  
2. various edits to
Section 8 to establish that a query has
a context while an expression does not

  
3. establish XPath 1.0 as
the default value for a
<propertyAlias> query

  
 

  
As it turns out, this was
probably the fewest number of
edits in order to achieve consistency between queryLanguage and
expressionLanguage. Restoring the <query> to the from-spec and
to-spec resulted
in some overlap with the expression variants but this hopefully won’t
cause any concern as we had this in the past and have agreed that
redundancy
was ok.