19.9.  Link
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19.9.  Link

A link is an instance of an association. In the UML metamodel Link is a sub-class of Instance. Within a sequence diagram links are created indirectly when an associated stimulus is created.

An link is represented on a sequence diagram in ArgoUML as a line connecting the instances concerned. However on a sequence diagram the representation is modified to reflect the type of action associated with the stimulus carried on the link (see Section 19.3, “ Stimulus ”).

19.9.1.  Link Details Tabs

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

ToDoItem

Standard tab.

Properties

See Section 19.9.2, “ Link Property Toolbar ” and Section 19.9.3, “ Property Fields For Link ” below.

Documentation

Standard tab.

Presentation

Standard tab.

[Note]Note

The values in the "bounds" field of the link are not editable, since they are determined by the properties of the endpoints of the line.

Source

Standard tab, but with no contents.

[Caution]Caution

A link should not generate any code, so having this tab active is probably a mistake.

Tagged Values

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

  • persistence (from the superclass, Instance. Showing the permanence of the state information associated with the link. Values transitory (state is destroyed when the link is destroyed) and persistent (state is preserved when the link is destroyed).

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

    [Note]Note

    Derived links 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 model elements are derived includes the tagged element documentation which is handled by the documentation tab under ArgoUML

Checklist

Standard tab for a Classifier.

19.9.2.  Link Property Toolbar

Go up

Navigate up through the package structure.

New Stereotype

This creates a new Stereotype (see Section 16.6, “ Stereotype ”) for the selected link, navigating immediately to the properties tab for that stereotype.

Delete

This deletes the link from the model

[Warning]Warning

This is a deletion from the model not just the diagram. To delete an link from the diagram, but keep it within the model, use the main menu Remove From Diagram (or press the Delete key).

19.9.3.  Property Fields For Link

Name

Text box. The name of the link. By convention link names start with a lower case letter and use bumpy caps to divide words within the name.

[Note]Note

ArgoUML does not enforce this naming convention.

Stereotype

Drop down selector. Link has no stereotypes by default in the UML standard.

Navigate Stereotype

icon. If a stereotype has been selected, this will navigate to the stereotype property panel (see Section 18.5, “ Stereotype ”).

Namespace

Text box. Records the namespace for the link. This is the package hierarchy.

Connections

List box. Lists the connections of the link, i.e. the link-ends.

Button 1 double click on the entry will navigate to the link-end.

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19.8.  Stimulus Return  Home Chapter 20.  Statechart Diagram Model Element Reference