19.5.2 Object Reference Parameters and IForeignObject

   As described in the Interworking Architecture chapter, Automation and COM Views must expose the IForeignObject interface in addition to the interface that is isomorphic to the mapped CORBA interface. IForeignObject provides a mechanism to extract a valid CORBA object reference from a View object.

   Consider an Automation View object B, which is passed as an in parameter to an operation M in View A. Operation M must somehow convert View B to a valid CORBA object reference.

   In Figure 19-5, Automation Views expose IForeignObject, as required of all Views.

   Automation ViewObject

   IDispatch IForeignObject

   ...

   Figure 19-5 Partial Picture of the Automation View

   19-16 Common Object Request Broker Architecture (CORBA), v3.0 July 2002

   The sequence of events involving IForeignObject::GetForeignReference is as follows:

• The client calls Automation-View-A::M, passing an IDispatch-derived pointer to Automation-View-B.

• Automation-View-A::M calls IDispatch::QueryInterface for IForeignObject.

• Automation-View-A::M calls IForeignObject::GetForeignReference to get the reference to the CORBA object of type B.

• Automation-View-A::M calls CORBA-Stub-A::M with the reference, narrowed to interface type B, as the object reference in parameter.