UML22 — behaviour of the shallow history state and deep history state

In the UML specification the behaviour of the shallow history state and deep history state are described (added below). The final state is seen as a real state in UML which can have entry actions and in which can be stayed. When a child composite state is in its final state and at a higher level a transition is taken to an other state and then to the deep history state we expect that the final state is set active again, instead that then default history state is made active. For example we have a composite state that does the setup of a piece of hardware and it is in the final state, but it doesn't leave the composite state because another condition is not true yet. When now the composite state is left at a higher level (for example emergency), then we go back according to the spec to the default history state, so we do the complete setup again, but we expect to return in the final state.

Shallow history entry: If the transition terminates on a shallow history pseudostate, the active substate becomes the most recently active substate prior to this entry, unless the most recently active substate is the final state or if this is the first entry into this state. In the latter two cases, the default history state is entered. This is the substate that is target of the transition originating from the history pseudostate. (If no such transition is specified, the situation is illegal and its handling is not defined.) If the active substate determined by history is a composite state, then it proceeds with its default entry. • Deep history entry: The rule here is the same as for shallow history except that the rule is applied recursively to all levels in the active state configuration below this one.

Disposition: Deferred to UML 2.4 RTF