[ebxml-cppa] ServiceBinding and Packaging Question

[Arvola Chan <arvola@tibco.com>]

In CPP/A 1.0, each CollaborationRole has one or more ServiceBinding. Each ServiceBinding references a DeliveryChannel and a Packaging. Each ServiceBinding can also have an arbitrary number of Override elements. Each Override element specifies a DeliveryChannel and a Packaging that should be used for a particular action.

 

 <element name="ServiceBinding">
  <complexType>
   <sequence>
    <element ref="tns:Service"/>
    <element ref="tns:Override" minOccurs="0" maxOccurs="unbounded"/>
   </sequence>
   <attribute name="channelId" use="required" type="IDREF"/>
   <attribute name="packageId" use="required" type="IDREF"/>
  </complexType>
  <unique name="action.const">
   <selector xpath=".//Override"/>
   <field xpath="@action"/>
  </unique>
 </element>

 

The DeliveryChannel that is referenced by a ServiceBinding can be considered a default delivery channel for the Service in question. In principle, it can be used for delivering messages for all actions associated with the Service for which no explicit Override element exists.

 

I question if each ServiceBinding should reference only a single Packaging element. Since every action message may have its own schema and may have to be described by a separate Packaging element, wouldn't it be more appropriate to have a repeating group of Packaging elements to be associated with a ServiceBinding element? Each action message that can possibly be delivered via the default channel associated with the ServiceBinding must be enumerated and its corresponding Packaging must be identified.

 

What would be the action that corresponds to a business level Receipt Acknowledgment or Acceptance Acknowledgment signal? When these messages are sent on their own (not piggybacked on response messages), their corresponding action name will have to be used as keys into the ServiceBinding for looking up the appropriate DeliveryChannel and Packaging description. Should we simply refer to these actions as ReceiptAcknowledgment and AcceptanceAcknowledgment?

 

I also have another question regarding Packaging. Consider the case of a business request message being delivered over a synchronous delivery channel, and either a receipt acknowledgment or a receipt acknowledgment exception signal may be returned? Should we have a choice mechanism whereby a SimplePart can be declared to be an XML document that conforms to one of several schemas (XSDs and DTDs)?

 

Thanks,

-Arvola