19.6. Event

An event is an observable occurrence. In the UML metamodel it is a child of ModelElement.

There are a number of different types of events that are children of event within the UML metamodel.

An event is represented by its name.

[Caution]Caution

The V0.14 release of ArgoUML does not allow entry of the parameters of the event.

[Caution]Caution

The V0.14 release of ArgoUML has only partially implemented events. In practice, only the name can be specified, there is no difference between the 4 kinds of events described above. The name field should be used to indicate that it is a signal, call, timing or change event.

19.6.1. Event Details Tabs

The details tabs that are active for events are as follows.

ToDoItem

Standard tab.

Properties

See Section 19.6.2, “Event Property Toolbar” and Section 19.6.3, “Property Fields For Event” below.

Documentation

Standard tab.

Source

Standard tab.

[Note]Note

In the fullness of time this tab will contain code to implement the event. This is not implemented in the V0.14 release of ArgoUML.

Constraints

Standard tab. ArgoUML only supports constraints on Classes and Features (Attributes, Operations, Receptions, and Methods), so this tab is grayed out.

Tagged Values

Standard tab. In the UML metamodel, an Event has the following standard tagged values defined.

  • derived (from the superclass, ModelElement). Values true, meaning the call event is redundant—it can be formally derived from other elements, or false meaning it cannot.

    [Note]Note

    Derived call events still have their value in analysis and design to introduce useful names or concepts, and in design to avoid re-computation.

[Note]Note

The UML Element metaclass from which all other artifacts are derived includes the tagged element documentation which is handled by the documentation tab under ArgoUML

19.6.2. Event Property Toolbar

Go up

Navigate up through the package structure.

Add parameter

This creates a new parameter for the event operation as the current parameter, navigating immediately to the properties tab for that parameter (see Section 17.8, “Parameter”).

[Warning]Warning

This feature is currently broken within ArgoUML and there is no way to enter parameters.

19.6.3. Property Fields For Event

Name

Text box. The name of the event. By convention event names start with a lower case letter and use bumpy caps to divide words within the name in the same way as operations.

[Note]Note

ArgoUML does not enforce this naming convention.

[Tip]Tip

For call events it makes sense to use the name of the associated operation. For signal events it make sense to use the name of the signal, prefixed by [sig]. For time events use the time expression, prefixed by [time] and for change events the change expression, prefixed by [change].

Stereotype

Drop down selector. An Event has no stereotypes by default in the UML standard, except when the Event is a Call Event. For a Call Event, the following stereotypes are defined: create and destroy.

Navigate Stereotype

icon. If a stereotype has been selected, this will navigate to the stereotype property panel (see Section 15.4, “Stereotype”).

Parameters

Text area, with entries for all the actual parameter values of the event (see Section 17.8, “Parameter”).

Button 1 double-click on any of the parameters navigates to that parameter, button 2 click brings up a pop up menu with four entries.

  • New. Create a new parameter and navigate to it.

  • Move Up. Only available where there are two or more parameters, and the parameter selected is not at the top. It is moved up one.

  • Move Down. Only available where there are two or more parameters listed, and the parameter selected is not at the bottom. It is moved down one.

  • Delete From Model. Deletes the selected parameter from the model.

Operations

Only present for a Call Event. The V0.14 release of ArgoUML does not allow entry of the operation.