PDME12 — PdmContext is insufficient as a TraversalCriteria

The CosGraphs module specifies that Traversals are be created by the
TraversalFactory::create_traversal_on() operation, which returns a Traversal
and takes 3 input parameters: a root Node, a TraversalCriteria, and a mode flag.

In the PDM Enablers PdmViews module, it is specified that PdmContext is a subtype of
TraversalCriteria, and thus a PdmContext can be used to create a Traversal. The
PdmContext is effective as a filter to specify that only the items of interest to the client
are returned. However, it is insufficient to create an effective Traversal object.
Nowhere is there defined a traversal path name, algorithm or strategy which indicates
which roles and relationships to follow.

As a possible solution, it is sugggested that the PdmContext not inherit
TraversalCriteria. Rather a TraversalCriteria should be created by a new interface's
operation, which takes as input both a PdmContext and some definition of a
PDM Enablers-specific traversal path.

Duplicate of 3154. Closed