Transition dialog box

Transitions

A transition is a relationship between two states, indicating that an object in the first state will perform specified actions and enter the second state when a specified event occurs and specified guard conditions are satisfied.

The "Transition" dialog box contains four tabs - "Properties", "Notes", "Tagged values" and "Stereotypes". For information on these standard dialog box tabs, please see "Standard dialog box tabs".

The "Properties" tab of the "Transition" dialog box

The "Properties" tab of the "Transition" dialog box is used to define values for a transition.

The "Properties" tab of the "Transition" dialog box

Key:

· "Received event": This is the event received which triggers the transition. The received event can be text entered in the field, or a reference to events defined in the current state machine.

· "Guard condition": This is the condition under which a transition may be triggered.

· "Expression of the action": This is an action realized when the transition is triggered. The combobox makes it possible to simply designate an operation (message call).

· "Expression of the sent event": This is an event sent by the transition once it has been triggered. A sent event can be text entered in the field, or a reference to existing events in the current state machine (combobox). Signals can also be referenced (shorthand for Signal sending event).

· "Final condition": This is a condition obtained once the transition has occurred (this can be useful for protocol state diagrams).