regrep 10/28/2005: Import Comment for Consideration on WS Profile

[Monica J Martin <Monica.Martin@Sun.COM>]

Farrukh and registry experts,
Here is what I found and you can assist in deciding if this is an item 
that needs to be addressed in the Web Services Profile for Registry. 
Take a WSDL that references an XML schema (.xsd) [Extend what is defined 
in WSDL v1.1 specification: http://www.w3.org/TR/wsdl#_example2]. I am 
only providing the details and then we can decide if it needs redress 
and if so when.

In this example, the stock quote schema may itself import another schema 
fragment. I think you could see this for example with UBL where the 
import a code list from somewhere else for their own core schema.

My question is if the http://example.com/stockquote/stockquote.wsdl 
imports the http://example.com/stockquote/stockquote.xsd, and we assume 
that the .xsd also has an import: What impact does this have on the 
Registry services if any. Is a WSDL validator set up to resolve the 
import of the imported schema? Or, does the import of the imported 
schema need to be specifically declared in the import statement in the 
.wsdl? The XML schema specification partially addresses this [1].

I think I indirectly brought this up because of significant discussions 
in WS-BPEL. There were two schools of thought:

  1. Require explicit import declaration of any imported document or
     fragment. Case cited above. What we found in WS-BPEL that even
     with explicit declaration of imports to an imported document,
     collisions may occur at the XML schema level and conflict
     detection may be required in implementation. I suggested in that
     case an implementer's hint. [2]
  2. Allow transitive imports and be silent on how this is resolved in
     processing, i.e. there is no explict requirement for the import of
     an imported document be specified in the WSDL.

On a related subject, do we need to address if other element definitions 
of the WSDL are defined by WSDL extensibility (that uses QName 
linking)?  Thanks.

[1] Section 4 (XML Schema: http://www.w3.org/TR/xmlschema-1/#composition)

   * The processor succeed in locating the �schema components�
     <http://www.w3.org/TR/xmlschema-1/#key-component> transitively
     required to complete an �assessment�
     <http://www.w3.org/TR/xmlschema-1/#key-va> (note that components
     derived from �schema documents�
     <http://www.w3.org/TR/xmlschema-1/#key-schemaDoc> can be
     integrated with components obtained through other means);.....

[2] 
http://www.oasis-open.org/apps/org/workgroup/wsbpel/download.php/14974/wsbpel_issues_list.html#Issue88 
(TC)
http://www.oasis-open.org/committees/document.php?document_id=14974&wg_abbrev=wsbpel 
(public)