UML Designer User's Guide

Relationship properties

To edit the properties of a relationship, double-click on the connector figure or select Focus from its pop-up menu. This opens a window from which you can edit the properties of the relationship represented by the connector figure. Note that these properties apply to the relationship model, rather than to the connector figure (although some of them might affect the visual appearance of the figure).

The relationship properties window has three pages: one for general properties, and one for each role (direction) of the relationship. Depending upon the type of relationship, some of the options might not be available.

For associations, you can use the properties window to specify constraints on the relationship. A constraint is a specific rule that restrains the allowed behavior of the relationship, such as cardinality (multiplicity). Constraints should be observed in your implementation.

Main page

The following settings are available on the Main page of the relationship properties window:

Link Name
The name of the relationship for the indicated direction. (The name you specify appears only if the Name label is displayed.)

Text
The text for the relationship in the indicated direction. This text will appear in any publications that include the relationship.

Role page

The following settings are available on each Role page of the relationship properties window:

Id
Specifies a unique internal identifier for the role.

Role Name
Specifies the role name that will appear on the diagram if role name labels are displayed.

Stereotype
Specifies any user-defined stereotype that applies to the relationship. You can select any available stereotype from the drop-down list. To define a new stereotype, add a Stereotype element to the model; you will then need to close and reopen the relationship settings in order to see the new stereotype.

UML Stereotype
Specifies the UML-defined stereotype that applies to the relationship. You can select from a list of four UML-defined stereotypes.

Is Unique
Specifies whether each instance of this relationship must be uniquely identifiable.

Is Immutable
Specifies whether an instance of this relationship can be altered once it is created.

Composition
Indicates whether the relationship represents an aggregation or composition association. Aggregation is indicated on the connector figure by an open diamond; composition is indicated by a solid diamond.

Aggregation indicates that the aggregated element is a child of the aggregating element. Composition is a stronger form of aggregation, indicating that the child element is an inherent part of the composing element and cannot be meaningfully separated.

Min/Max
Specifies the multiplicity for this end of the association. (This is the same as selecting Multiplicity>Edit From or Multiplicity>Edit To from the pop-up menu of the connector figure.

Multiplicity is defined in termed of a minimum cardinality and a maximum cardinality. The minimum cardinality (0-n) defines the minimum number of instances required; the maximum cardinality (0-n or * for many) defines the maximum number of instances allowed.

Ordering
Specifies whether the set of instances of a relationship are considered ordered or sorted:

Cycles
Specifies whether cyclic references are allowed using this relationship:

Delete Check
Specifies whether this relationship has deletion constraints:

Implementation
Specifies properties that do not affect the semantics of the relationship but do affect your implementation:

Attributes

Opens a window from which you can specify any constrained attributes (qualifiers) for this end of the association. You can select any attribute defined in the class or in any protocol it conforms to; you can also create new attributes from this window. Qualifications appear in a box at the end of the connector figure, if the option is selected to display qualified attributes.


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