A node is a run-time physical object on which components may be deployed. In the UML metamodel it is a sub-class of Classifier.
A node is represented on a class diagram as a three dimensional box, labeled with its name.
The details tabs that are active for nodes are as follows.
- ToDoItem
Standard tab.
- Properties
See Section 21.2.2 and Section 21.2.3 below.
- Documentation
Standard tab.
- Style
Standard tab. The Bounds: field defines the bounding box for the node on the diagram.
Warning Beware that in the current release of ArgoUML, the bounding box just refers to the front face of the cube. This means that the three dimensional top and side may be ignored, for example when determining the limits of a diagram for saving graphics.
Altering the Shadow entry has no effect.
- Source
Standard tab, but with no contents.
Caution A node should not generate any code, so having this tab active is probably a mistake.
- Constraints
Standard tab. There are no standard constraints defined for Node within the UML metamodel.
- Tagged Values
Standard tab. In the UML metamodel, Node has the following standard tagged values defined.
persistence (from the superclass, Classifier). Values transitory, indicating state is destroyed when an instance is destroyed or persistent, marking state is preserved when an instance is destroyed.
semantics (from the superclass, Classifier). The value is a specification of the semantics of the node.
derived (from the superclass, ModelElement). Values true, meaning the node is redundant—it can be formally derived from other elements, or false meaning it cannot.
Note Derived nodes still have their value in analysis to introduce useful names or concepts, and in design to avoid re-computation.
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
Go
upNavigate up through the package structure.
Go
backNavigate back to the previous artifact.
Warning This feature is currently broken within ArgoUML and there is no guarantee where (if anywhere) this button will take you.
Go
forwardNavigate forward to the next artifact.
Warning This feature is currently broken within ArgoUML and there is no guarantee where (if anywhere) this button will take you.
DeleteThis deletes the node from the model
Warning This is a deletion from the model not just the diagram. To delete a node from the diagram, but keep it within the model, use the main menu Edit/Remove From Diagram (Ctrl-R).
- Name
Text box. The name of the node. The name of a node has a leading capital letter, with words separated by “bumpy caps”.
Note ArgoUML does not enforce this naming convention.
- Generalizations
Text area. Lists any node that generalizes this node.
Button 1 click navigates to the generalization and opens its property tab.
Button 2 click yields a drop down menu with five entries
Open. Navigate to the selected generalization.
Add. Add a new generalization. Note that the new generalization is added to the model, but not the diagram. You will need to find it in the navigation pane and add it from there.
Tip It is far easier to add generalizations by drawing them on the relevant diagram in the editing pane.
Delete. The link from the generalization to the node (but not the generalization itself) is removed.
Tip This does not remove the generalization from the model or the diagram, leading to potentially very confusing diagrams. It is usually far easier to remove generalizations from the editing pane.
Move Up. Only available where there are two or more generalizations listed, and the generalization selected is not at the top. It is moved up one.
Move Down. Only available where there are two or more generalizations listed, and the generalization selected is not at the bottom. It is moved down one.
- Stereotype
Drop down selector. ArgoUML provides the stereotypes, machine, organization and person.
Caution ArgoUML also provides the stereotype realize for node instances. This appears to be an error, since this stereotype properly belongs to the Abstraction metaclass.
Warning Node is a type of classifier, and so should have the stereotypes of a classifier by default in the UML standard. However these are missing in the current release of ArgoUML.
- Navigate Stereotype
icon. If a
stereotype has been selected, this will navigate to the
stereotype property panel (see Section 16.4).- Modifiers
Check box, with entries abstract, final and root.
abstract is used to declare that this node cannot be instantiated, but must always be specialized. The name of an abstract node is displayed in italics on the diagram.
final indicates that this node cannot be further specialized.
root indicates the node can have no generalization.
- Namespace
Text box. Records the namespace for the node. This is the package hierarchy.
Button 1 click on the entry will navigate to the package defining this namespace (or the model for the top level namespace).
- Specializations
Text box. Lists any specialized node (i.e. for which this node is a generalization.
button 1 click navigates to the generalization and opens its property tab.
Button 2 click yields a drop down menu with five entries
Open. Navigate to the selected generalization.
Add. Add a new generalization. Note that the new generalization is added to the model, but not the diagram.
Tip It is far easier to add generalizations by drawing them on the relevant diagram in the editing pane.
Delete. The link from the generalization to the node (but not the generalization itself) is removed.
Tip This does not remove the generalization from the model or the diagram, leading to potentially very confusing diagrams. It is usually far easier to remove generalizations from the editing pane.
Move Up. Only available where there are two or more specializations listed, and the specialization selected is not at the top. It is moved up one.
Move Down. Only available where there are two or more specializations listed, and the specialization selected is not at the bottom. It is moved down one.
- Components
Text box. Lists any components (see Section 21.4) designed to be deployed on this type of node.
Button 1 click navigates to the selected entry, button 2 gives a pop up menu with three entries.
Open. Navigate to the selected component.
Move Up. Only available where there are two or more components, and the component selected is not at the top. It is moved up one.
Move Down. Only available where there are two or more components listed, and the component selected is not at the bottom. It is moved down one.