Transition Specification--Detail Tab

Figure 59 State Transition Specification--Detail Tab

Guard Condition

Conditional state transitions are triggered only when the conditional expression evaluates to true. Conditions are denoted by surrounding brackets:

Event (args) [condition] / Action ^target.someEvent (args)

To add a condition, click Guard Condition on the State Transition Specification and type the conditional expression. You may also include a condition by selecting the event label and changing the text.

Transition Between Substates

Transition between substates is useful when a transition is placed to or from a substate that has been hidden from view. The From field displays the state name from which the transition is initiated. The To field displays the state name to which the transition is pointing. Both fields are active at all times.

To enter a transition substate, click the scrolling arrow on the right side of the field. A list of potential transition substates will be presented. The list includes the name of all the states that reside within the bounds of the top level superstate, including the superstate. Select a state from the list.

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Decision Specification

A Decision Specification allows you to display and modify the properties and relationships of a decision on a statechart diagram or activity diagram.

The Decision Specification consists of the following tabs: General, Transitions, and Swimlanes.