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


Help: OASIS Mailing Lists Help | MarkMail Help

wsrf message

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

Subject: Re: [wsrf] Proposed resolution to WSRF 174 - references to instances ofMDDs

Dave, you are right that the proposal made no changes to

But you have reminded me of an observation that Dan made to the TC [1] that
we have not finished with. This observes that, since we now define at most
one MDD per WS-Resource, we can simplify the type of
MetadataDescriptorLocation from "list of pairs of URIs" to a single URI
that provides information on the location of the MDD. The reason there is
currently a list of pairs or URIs is so that we could (in the past)
accomodate a number of different MDDs, each of which pertains to a specific
namespace (the first URI in the pair). We have moved away from this and now
need only a single URI for the location of the single MDD.

In order to have a single, consistent story for locating the MDD, I propose
the following additions to the resolution of issue 174:

Change the definition of the wsrmd:MetadataDescriptorLocation from
"wsrmd:PairsOfURIType" to "xsd:anyURI"
Specifically, change the schema from this:

    <!-- ======================== Utility Types ======================= -->
      <xsd:simpleType name="PairsOfURIType">
        <xsd:list itemType="xsd:anyURI" />

    <!-- ================  PortType Attribute Extensions ================
      <xsd:attribute name="metadataDescriptorLocation"
    type="wsrmd:PairsOfURIType" />

to this:

    <!-- ================  PortType Attribute Extensions ================
      <xsd:attribute name="metadataDescriptorLocation" type="xsd:anyURI" />

Further, change XML snippets to reflect this - for example lines 235-241
   <portType name="OperatingSystem"
           ”http://example.com/metadataDescriptors/OperatingSystem.wsrmd” >

Change "10.1 Extending WSDL 1.1 PortType" to read:


    <wsdl:definitions …>
        <wsdl:portType …
        … >

This definition is further constrained as follows:


If this attribute appears on a WSDL 1.1 portType element its value MUST be
a QName that corresponds to a MetadataDescriptor component. Further, the
value of the MetadataDescriptor component contained in that document MUST
have {interface} that matches the QName of the portType containing
@wsrmd:metadataDescriptor. Any service that implements this portType MUST
be associated with a MetadataDescriptor that is, or specializes the
MetadataDescriptor identified by the value of this attribute.


If this attribute appears on a WSDL 1.1 portType element its value MUST be
a URI that corresponds to a URL at which can be found more information
about the MetadataDescriptor document, such as an XML document containing a
MetadataDescriptor Definitions element as its root element.


Ian Robinson

             David Snelling                                                
             K.Fujitsu.com>                                             To 
                                       Ian Robinson/UK/IBM@IBMGB           
             04/04/2006 14:20                                           cc 
                                       Re: [wsrf] Proposed resolution to   
                                       WSRF 174 - references to instances  
                                       of MDDs                             


This sounds very good and I agree. Thanks for the write up.

One question of clarification. This proposal makes no changes to the
WSDL extension part of the spec and the
/wsdl:portType/@wsrmd:metadataDescriptor remains a QName. Correct?

On 4 Apr 2006, at 12:26, Ian Robinson wrote:

> On the TC call on Mon Apr 3 we discussed an alternative resolution to
> that
> originally proposed for issue 174 for obtaining the values of metadata
> descriptor document instances that might be specific to a WS-Resource
> instance and potentially dynamic (hence factored as a RP). Instead of
> introducing an additonal RP that contains the value of an RMD instance
> doc
> for a WS-Resource, this proposal changes the type and some semantics
> of the
> existing MetadataDescriptorRef RP (which contains a reference to an RMD
> instance doc).
> Regardless of which solution we follow, we need to start by fixing a
> problem in theRMD wd-08 draft so that:
> Line s 897/898,
>       <xsd:element name="MetadataDescriptor"
>                    type="wsrmd:MetadataDescriptorRef"/>
> should be
>       <xsd:element name="MetadataDescriptorRef"
>                    type="wsrmd:MetadataDescriptorRefType"/>
> This resolution then proposes the further change that the definition of
> MetadataDescriptorRefType be changed to wsa:EndpointReferenceType. The
> value of MetadataDescriptorRef is then an EPR to a "metadata
> WS-Resource"
> associated with the original WS-Resource.
> The description of this element should be changed as follosw:
> "
> The constraints on this element are as follows:
> /wsrmd:MetadataDescriptorRef
> This element is an EndpointReference to a "metadata WS-Resource"
> associated
> with the target WS-Resource. This metadata WS-Resource has a resource
> properties document that is the MetadataDescriptor document of the
> target
> WS-Resource. The metadata WS-Resource MUST support the
> wsrf-rpw:GetResourcePropertiesDocument message exchange and MUST
> respond to
> such a request by returning the MetadataDescriptor document that
> describes
> the target WS-Resource.
> "
> The description of
> "/wsrmd:MetadataDescriptorRef/@metadataDescriptorLocation" should be
> removed from this section.
> <TC discussion not intended to be included in the resolution>
> In general, if a WS-Resource "A" has an associated metadata WS-Resource
> "mdA" then the resource properties document associated with mdA *is*
> the
> metadescriptor document associated with A. Information about A's
> (potentially dynamic) instance metadata can then be queried (and
> potentially updated) using normal WSRF-RP message exchanges targeted
> at the
> mdA EPR.
> A constraint on metadata WS-Resources, above and beyond that of general
> WS-Resources, is that they MUST support the GetResourcePropertyDocument
> message exchange (which is optional for general WS-Resources). The
> constraint needs to be stated in the RMD doc in the section "10.2 Using
> Resoure Property Elements to expose MetadataDescriptors "
> </TC discussion not intended to be included in the resolution>
> The schema should then define:
>     <!--
>     <MetadataDescriptorRef>
>       <wsa:Address>URI</wsa:Address>
>       <tns:SomeReferenceParameter>xsd:any<tns:SomeReferenceParameter> ?
>     </MetadataDescriptorRef>
>     -->
>       <xsd:complexType name="MetadataDescriptorRefType" >
>         <xsd:complexContent>
>           <xsd:extension base="wsa:EndpointReferenceType">
>           </xsd:extension>
>         </xsd:complexContent>
>       </xsd:complexType>
>     <xsd:element name="MetadataDescriptorRef"
>                    type="wsrmd:MetadataDescriptorRefType" />
> Regards,
> Ian Robinson

Take care:

     Dr. David Snelling < David . Snelling . UK . Fujitsu . com >
     Fujitsu Laboratories of Europe
     Hayes Park Central
     Hayes End Road
     Hayes, Middlesex  UB4 8FE

     +44-208-606-4649 (Office)
     +44-208-606-4539 (Fax)
     +44-7768-807526  (Mobile)

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