OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

wsbpel message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: RE: [wsbpel] Issue - 46 - Namespace for the document fragment representing a part


+1.  The more examples we can generate (normative or not) the better.

	-----Original Message----- 
	From: Chris Keller [mailto:chris.keller@active-endpoints.com] 
	Sent: Thu 8/7/2003 8:10 PM 
	To: 'Sanjiva Weerawarana'; 'Ugo Corda'; wsbpel@lists.oasis-open.org 
	Cc: 'David RR Webber - XML ebusiness' 
	Subject: RE: [wsbpel] Issue - 46 - Namespace for the document fragment representing a part
	
	

	Sanjiva,
	
	Thanks for chiming in.
	
	I believe, for clarity, we need more examples.  It may be clear to the
	experts how a bpel engine should reconstitute a document fragment when
	it is transmitted in any binding.  However I am not sure it is clear to
	everyone else.  Let's make sure it is clear so that the queries that
	user's write will not result in failures based on the engine they are
	using or the partner's binding they are dealing with.  IMO we need to
	spell it out with examples or we will end up with problems.  There are
	too few examples of query usage given how heavily people will rely on
	queries.
	
	The other issue with these document fragments being reconstituted from
	any binding is that they can be modified by assign activities.  If we
	aren't careful it will be difficult to validate these modified
	fragments. 
	
	In summary if the only outcome of this issue is that we add a few more
	examples. And state precisely what a part/query context is (for both
	part as type and part as element) so that it is unambiguous under any
	binding (as bpel is binding independent).  Plus as a real nice to have
	make sure that the resulting parts can be validated even after use
	within a <to> assign.  Then it was worth raising the issue.
	
	Chris
	
	-----Original Message-----
	From: Sanjiva Weerawarana [mailto:sanjiva@watson.ibm.com]
	Sent: Thursday, August 07, 2003 3:10 PM
	To: chris.keller@active-endpoints.com; 'Ugo Corda';
	wsbpel@lists.oasis-open.org
	Subject: Re: [wsbpel] Issue - 46 - Namespace for the document fragment
	representing a part
	
	As the culprit behind the XPath stuff in BPEL 1.1, I'd like to weigh
	in on this. I was also on the XSLT WG where XPath 1.0 was defined.
	
	"Chris Keller" <chris.keller@active-endpoints.com> writes:
	> Sorry if the wording of my replies misled you.  My Issue is not really
	> about the part as type and property alias queries, but also XPath 1.0
	> vs. XPath 2.0 and the queries within bpel assignments and expressions.
	> Even if we assume no namespaces in the document fragment under the
	part
	> as type case (which we should think hard about as validation would be
	an
	> issue), many of the messages would most definitely contain namespaces
	> and as such require qualification in XPath 1.0.
	
	XPath 1.0 does not require qualification unless the element/attribute
	itself is qualified. How else could it work??
	
	What's the validation for unqualified stuff? I don't know of any myself.
	
	So as Ugo said, if the schema for the complex type that part/@type
	is referring to has qualified stuff, then stuff that follows
	/partname/..
	would indeed be qualified. If not it would not be. That's it.
	
	Since we're still dealing with XPath 1.0 let's just focus on that and
	not worry about what XPath 2.0 does or says. In particular, I'm not
	qualified to debate that as I left the WG and haven't had the time
	to follow the specs. I'm sure there are more expert people here who
	can comment.
	
	W.r.t. the general issue of what namespaces are in scope for an XPath
	expression, XPath defines a notion of a context. So when evaluating
	an XPath expression the namespaces defined by the context are assumed
	to apply to the XPath expression as XPath itself has no way to define
	namespaces. In particular, in BPEL when you say
	"bpel:getContainerData()"
	say, the "bpel" prefix is resolved w.r.t. the namespaces visible on
	the element which contains an attribute whose value this expression is.
	
	So I don't think there is any issue whatsoever w.r.t. the namespaces
	of part names or any other name used in any XPath expression in BPEL.
	I'm not sure whether the spec clearly says how the XPath context should
	be computed (IIRC something was added to clarify that) but there's
	only one meaningful way to do it (see above paragraph) IMO.
	
	Bye,
	
	Sanjiva.
	
	
	
	
	
	---------------------------------------------------------------------
	To unsubscribe, e-mail: wsbpel-unsubscribe@lists.oasis-open.org
	For additional commands, e-mail: wsbpel-help@lists.oasis-open.org
	
	



[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]