An action specifies an executable statement and is an abstraction of
a computational procedure that can change the state of the model. In the
UML metamodel it is a child of
Model
Since in the metamodel an ActionSequence is itself an Action that is an
aggregation of other actions (i.e. the "composite" pattern),
an ActionSequence may be used anywhere an
action may be.
There are a number of different types of action that are children of action within the UML metamodel.
CreateAction. Associated with a classifier, this action creates an instance of that classifier.CallAction. Associated with an operation of a class, this action calls the given operation.AssignmentAction. An action used to assign a new value to a link or an attribute link.ReturnAction. An action used to return a result to an earlier caller.SendAction. Associated with a signal, this action causes the signal to be raised.TerminateAction. Causes the invoking object to self-destruct.UninterpretedAction. An action used to specify language-specific actions that do not classify under the other types of actions.DestroyAction. Destroys the specified target object.
An action is represented on the diagram by the text of its expression.
The details tabs that are active for actions are as follows.
ToDoItemStandard tab.
PropertiesSee Section 19.3.2, “Action Property Toolbar” and Section 19.3.3, “Property Fields For Action” below.
DocumentationStandard tab.
SourceStandard tab, containing the expression for the action.
![[Note]](images/note.png)
Note In the fullness of time this tab will contain code to implement the action. This is not implemented in the current release of ArgoUML.
ConstraintsStandard tab. ArgoUML only supports constraints on Classes and Features (Attributes, Operations, Receptions, and Methods), so this tab is grayed out.
Tagged ValuesStandard tab. In the UML metamodel,
Actionhas the following standard tagged value defined.derived(from the superclass,ModelElement). Valuestrue, meaning the action is redundant—it can be formally derived from other elements, orfalsemeaning it cannot.Note Derived actions still have their value in analysis and design to introduce useful names or concepts, and in design to avoid re-computation.
Note The UML
Elementmetaclass from which all other artifacts are derived includes the tagged elementdocumentationwhich is handled by the documentation tab under ArgoUML
Go upNavigate up through the hierarchical structure.
DeleteThis deletes the Action from the model
NameText box. The name of the action. By convention action names start with a lower case letter and use bumpy caps to divide words within the name.
Note ArgoUML does not enforce this naming convention.
ExpressionText box. The expression that defines the action.
![[Caution]](images/caution.png)
Caution The V0.14 release of ArgoUML only partially implements actions. As a practical convention it is suggested that call actions are shown as the name of the operation generating the action with any arguments in parentheses and that send actions are shown as the name of the signal generating the action with any arguments in parentheses. Return actions should be shown as the expression for the value they return, or empty otherwise. Create and destroy actions should shown as
create(<target>)anddestroy(<target>). Terminate action should be shown asterminate.LanguageText box. This is not part of standard UML, but in the partial implementation of actions currently available in UML it may be useful to indicate that the expression is written in a particular programming language.