Re: Import/Include - a proposal

> SRT: Import/Include in WS-CDL
>
> Proposal:
> Given that the XInclude mechanism [ref] has been created for the 
> express purpose of providing a generic mechanism for recognizing and 
> processing inclusions in XML grammars I propose that we use it as the 
> basis for our own importation mechanism in WS-CDL. This mechanism 
> would be a syntactic inclusion identical to XInclude and would conform 
> to the processing model of XInclude. Parsing and validation of a 
> merged info-set (the result of XInclusion) would then be a separate 
> and orthogonal process.
>
> This would allow us to close the following issues:
> Issue 469 - because it does a merge on info-sets and the correctness 
> of the result is WS-CDL's problem. 

mm1: Should then WS-CDL address this problem then a separate issue?

> Issue 484 - because XInclude doesn't care I would suggest neither 
> should we. 

mm1: If we include at multiple levels of the choreography, do we raise 
any compatibility issues with BPEL for example? BPEL only imports at the 
process level. Does this have any affect on the validity of the 
choreography description? I agree this may be a separate, non-syntactic 
issue.

> Issue 485 - doesn't overide at all and in cases with clashes it could 
> be a schema error. 

mm1: From reading the xinclude note, it appears that the namespace of 
the included item is retained.  I agree that could result in a schema 
error, and therefore could be recognized by WS-CDL in validation correct?

> Issue 561 - see 485 above 

mm1: Agreed - see comments above.

> Issue 609 - not so sure on this one but my sense is that it is 
> irrelevant to a syntactic inclusion mechanism and so can be closed 

mm1: Therefore, we will not address any non-syntactic issues, correct?

> Issue 611: XInclude handles this (see processing model and uri 
> resolution). 

mm1: We should recognize that xinclude requires the making the base URI 
property required instead of optional. Perhaps this is a hint to 
implementers or it may be implicit in our reference to the use of xinclude.

> For summary of above issues see 
> (http://lists.w3.org/Archives/Public/public-ws-chor/2004Jul/att-0015/draft-import-mm2-062904.pdf) 


mm1: It appears that you wish to close all issues to address syntactic 
inclusion only. If that is indeed correct, I would propose, please, that 
the specification indicate that WS-CDL only explicitly addresses 
syntactic inclusion. Thanks.

> Excerpts below are taken from http://www.w3.org/TR/xinclude/
>
> 1.2 Relationship to XML External Entities
> ... XInclude operates on information sets and thus is orthogonal to 
> parsing....
>
> 1.3 Relationship to DTDs
>
> XInclude defines no relationship to DTD validation. XInclude describes 
> an infoset-to-infoset transformation and not a change in XML 1.0 
> parsing behavior. XInclude does not define a mechanism for DTD 
> validation of the resulting infoset.
>
> 1.4 Relationship to XML Schemas
>
> XInclude defines no relationship to the augmented infosets produced by 
> applying an XML schema. Such an augmented infoset can be supplied as 
> the input infoset, or such augmentation might be applied to the 
> infoset resulting from the inclusion.
>
> 1.5 Relationship to Grammar-Specific Inclusions
>
> Special-purpose inclusion mechanisms have been introduced into 
> specific XML grammars. XInclude provides a generic mechanism for 
> recognizing and processing inclusions, and as such can offer a simpler 
> overall authoring experience, greater performance, and less code 
> redundancy.
>
>
> 4 Processing Model
>
> Inclusion as defined in this document is a specific type of [XML 
> Information Set] transformation.
>
> [Definition: The input for the inclusion transformation consists of a 
> *source infoset*.] [Definition: The output, called the *result 
> infoset*, is a new infoset which merges the source infoset with the 
> infosets of resources identified by IRI references appearing in 
> xi:include elements.] Thus a mechanism to resolve URIs and return the 
> identified resources as infosets is assumed. Well-formed XML entities 
> that do not have defined infosets (e.g. an external entity with 
> multiple top-level elements) are outside the scope of this 
> specification, either for use as a source infoset or the result infoset.
>
> xi:include elements in the source infoset serve as inclusion 
> transformation instructions. [Definition: The information items 
> located by the xi:include element are called the *top-level included 
> items*]. [Definition: The top-level included items together with their 
> attributes, namespaces, and descendants, are called the *included 
> items*]. The result infoset is essentially a copy of the source 
> infoset, with each xi:include element and its descendants replaced by 
> its corresponding included items.

Received on Tuesday, 13 July 2004 12:34:58 UTC