UML Modeling Techniques > System modes modeling > Creating state machine items > Creating and defining an event action block
Creating and defining an event action block
You can create Event Action Blocks on Atomic States, Concurrent States. In addition, when you create a Transition, Modeler creates a blank Event Action Block on that Transition.
To create an event action block:
1. On the State Diagram toolbar, click the Event Action Block button.
2. On the State Diagram, click the Atomic State, Concurrent State, Sequential State or Transition for which you want to create an Event Action Block.
Event Action Blocks are not shown in the Packages pane, but they are shown in the Relationships pane.
3. Type the text for the Event Action Block's Action property, and then press the Enter key.
In a Modeler browser, right-click the Atomic State, Concurrent State or Sequential State that is to own the Event Action Block, point to New, and then click Event Action Block.
An Event Action Block is created by default for a Transition, and a Transition can own only one Event Action Block.
To define an event action block:
1. Open the Event Action Block's property pages.
2. Click the Options tab.
3. In the Trigger Type list, click the required trigger type. For more information, see Accept event action (dictionary item).
4. Specify the Guard Conditions and Actions.
If you refer to any dictionary items, use model object references in the rich text.
5. If the trigger type is Signal or Call, link the Event Action Block with the required Event or Operation. You can do this through the Call.
If the trigger type is Time, type the Time Expression.
If the trigger type is Change, type the Change Expression.
If you drag an Event to an Event Action Block, Modeler sets the Trigger Type of the Event Action Block to Signal and links the Event you dragged.
You can change an Event Action Block's Expression, Action or Guard Condition property by right-clicking the Event Action Block, pointing to Edit, and then clicking Trigger (to set the Expression property), Action or Guard.