UML Weekend Crash Course™ - To Parent Directory

Session 21—Applying the Basic Statechart to the Case Study 225
Likewise, the Statechart allows many events to transition out of the same state. Each event
may trigger an action. When all the actions associated with the transitions out of a state
are the same, you can model them as a single exit action. Place the exit action description
in the internal transition compartment of the state.
When an action is directed at an object other than one modeled by the Statechart
diagram, use the dot notation to qualify the action. Place the object name and a
period in front of the action expression.
When an event takes place it sets off a series of responses in the form of actions and
activities. The order of execution for the actions and activities is:
1. If an activity is in progress in the current state, interrupt it.
2. Execute the exit: action(s).
3. Execute the actions associated with the event that started it all.
4. Execute the entry: action(s) of the new state.
5. Execute the activity or activities.
QUIZ YOURSELF
1. What is an entry action (See “Defining Entry and Exit Actions.”)
2. What is an exit action (See “Defining Entry and Exit Actions.”)
3. How do you indicate that an action should be performed on another object
(See “Defining Send Events.”)
4. What is the first thing that happens when an event takes place (See “Order of
Events.”)
5. When an event takes place, which happens first, the exit actions or the actions
associated with the triggering event (See “Order of Events.”)