[infod-wg] action 26

[Djaoui, A (Abdeslem)]

>>26      We will need to update spec to use WS-RF resource properties and operators. But our
>>        query semantics might be different than those of WSRF; so we'll have to be careful
>>        about how we structure the registry to allow it.
>>        - Date: 1 Jul 2005
>>        - Owners:  Abdeslem
>>        - target date: 28 Jul 2005

RECAP:
======
In WSRF the composition of a stateful resource and a web service is refered to as a WS-Resource. A message to the web service includes a component that identifies the resource to be used in the execution of the message. The properties of a WS-Resource are defined in a resource properties document as part of the web service description (WSDL). A standard set of message exchanges for querying or updating the property values of the WS-Resource are also defined. 

OPERATIONS:
===========
1)         Retrieve the values of one or more properties of a WS-Resource
		GetResourcePropertyDocument
 		GetResourceProperty
		GetMultipleResourceProperties


2)         Update the values of one or more properties of a WS-Resource
		PutResourcePropertyDocument
		<wsrf-rp:SetResourceProperties>
   		{
    		<wsrf-rp:Insert >
   		   {any}*
   		 </wsrf-rp:Insert> |
    		<wsrf-rp:Update >
    		  {any}*
    		</wsrf-rp:Update> |
    		<wsrf-rp:Delete ResourceProperty='QName' />
  		 }+
  		</wsrf-rp:SetResourceProperties>
	A WS-Resource MAY support the message exchange defined in this section that allows a requestor to modify the values of multiple resource properties of a WS-Resource.

		InsertResourceProperties
		UpdateResourceProperties
		DeleteResourceProperties
	These operations apply to values of a single resource property from the resource properties document of a WS-Resource.

3)         Query across the values of one or more properties of a WS-Resource

 		<wsrf-rp:QueryResourceProperties>
    			<wsrf-rp:QueryExpression Dialect='URI'>
      			xsd:any
    			</wsrf-rp:QueryExpression>
  		</wsrf-rp:QueryResourceProperties>
	The context of the expression is to be evaluated against the resource properties document of the WS-Resource identified by the request.
	The URI specifies the type of expression. There are two well known dialects corresponding to the two versions of the XPath language.
	When a portType includes the definition of the QueryResourceProperties operation, it MUST also include a reference to the wsrf-rp:QueryExpressionDialect Resource Property. This resource property declares one or more QueryExpression dialects that are supported by the Web service.

DISCUSSION:
==========
The InfoDResgistry as a WS-Resource will expose a resource properties document and everything in WSRF applies to this resource properties document (including WS-ResourceLifetime, querying accross many properties, ...). REMINDER: There is ONE resource property document per portType. So an endpoint will correspond to ONE resource properties document. 
The real question is WHAT do we expose as resource properties, the resource properties document being only a projection (or a view) of the full state of the InfoDRegistryegistry. If we expose the full state then we can use WSRF as is, (probably augmented with XQuery). If we only expose part of the state, then we are free to structure the rest of the internal state the way we want and use any query semantics we need. 

In summary WSRF semantics only apply to the resource properties document. This document is a partial (but could be full) view of the internal state of the InfoDRegistry. The state that is not exposed as part of this document is not constrained by WSRF semantics.


Abdeslem