IsNavigable   The value of the isNavigable property specifies whether an association can be traversed from the source (far end) to the target (near end). It is indicated graphically by an open headed arrow.

Explanation

The isNavigable attribute indicates whether a classifier at a source (far) end can traverse the relationship to the target (near) end. The value of true signifies that the traversal from source (far) end to target (near) end is supported. Expressions use the target role name. An association must be navigable in at least one direction, and by default if all association ends are not adorned with an isNavigible indicator the meaning is that the association can be traversed in all directions. In the case of a binary association (involving two classifiers) the association is said to be bi-directional. Some confusion surrounds the concept of traversal. When the isNavigable marker or attribute is set to true it implies that the association provides some type of mechanism for the traversal from the source (far) end to the target (near) end. It does not mean that if the isNavigable attribute is set to false that the association cannot be traversed at all, it simply means that the association does not provide a mechanism for this to happen. In practical terms it might require a source classifier to provide its own device for the traversal such as searching through the classifiers at the target end.

Related Entries

Association End  Base Type An association end is related to the isNavigable property because this attribute is added to an association end to increase the precision of the semantics, describing an aspect of the way the classifier participates in the association relationship.