An action state is a state that contains one internal action, which, as soon as it is completed, causes a transition out of the action state. An action state is used to model a step in the execution of a procedure.
Action states should not have internal transitions or outgoing transitions based on explicit events; normal states are used for this situation.
An action state contains an action expression, that is listed in the Action State symbol.
Internal action
The action may be described by natural language, pseudocode, or programming language code. It may use only attributes and links of the owning class. You may also type a business name of the action in the Business Name property. You may also define the process of the action.
Modeling behavior of a class
If you are modeling behavior of a class in the system, you may add the class to the Action State definition in the Class Name (Class) property. You may also define Variables that are affected by the action in the State Variables property. A State Variable describes the attribute of the owning class (specified in the Action State definition), and its initial value.
Example
1 Create an Action State and open its definition, for example Change Customer's Address.
2 Specify the action performed by the class while in this state, such as typing in Change Address in the Action property.
3 Specify an owning class in the Class Name (Class) property, for example Customer, containing attributes Name, Address, and ID.
4 Specify an Activity State Variable for the Action State, for example, Address.
5 Click Definition for the Address state variable, and select the Choices button for the Variable (Class Attribute) property. You will see a list of all attributes of the owning class (Customer, selected above).
6 Drag in the name of an attribute that will undergo change by the action of this action state, for example Address.
7 Specify an initial value of the attribute, in this case an initial address. You are modeling that this address will be changed by the action of the Action State.