The states in a state model are connected by transitions. Both state and transition resources are containers for rules, which control how each instance changes states and property values.
Typically, transitions take an instance from one state to another state. Self transitions connect a state to itself, thereby reprocessing the rule set until conditions are met to transition to a different state. Each time the instance loops back to the state, it triggers the entry action, and each time it leaves the state, it triggers the exit action.
This subsection presents BusinessEvents behavior when transitioning into and out of composite and concurrent states. This discussion mentions entry and exit actions, which you can learn about in
Entry and Exit Actions.
When a transition enters or exits a composite state, it triggers the composite state’s entry or exit action. In the case of nested composite states, each time a transition passes the boundary of one of the composite states, it triggers the assigned action.
You can only transition into and out of a concurrent state through the boundaries. You cannot transition into or out of a state directly as you can with composite states.
As with nested composite states, to-boundary and from-boundary transitions trigger an entry or exit action each time they enter or exit a nested concurrent state.