Context Conduction in cyclic RIM graphs
This page documents an Open MnM Hot Topic, i.e. a methodology issue requiring a resolution from Modeling and Methodology.
Introduction
All the context conduction rules we have presently defined assume that they apply within the context of a DAG (directed acyclic graph). However there's no implicit rule that all uses of the RIM must be in a DAG, and indeed, there are several rational uses this. And RIMBAA already have this as a possibility.
The RIM ITS will allow serialisation of a cyclic RIM graph.And this raises the question, what does it mean if a class appears in two different places in a RIM graph where the conducted context is different?
Keith says:
This can be defined, the key question is whether context is accumulated via all references, or only through the appearance by value of the RIM class. Interestingly enough, the same RIM class appearing in a document or message using the XML ITS in two different places with the same identifier is the same instance, and so inherits context from both placements. It’s simply a matter of whether the context is navigable at both locations at the same time, which is usually not the case (implementation defined). I would apply this rule: that a reference or value representation of a RIM class inherits context at its point of placement, and that context SHALL be navigable from that location, but need not be navigable across all locations.
Grahame says:
Actually, it's no different to the two classes with the same identifier, where the two classes appear in different documents. So this is something that already happens, but I'm not aware of any ruling on the matter.
