An Identifier may consist of multiple Attributes. Each Attribute component of an Identifier constitutes an Identifier Attribute, alternatively called an ‘attribute in ID’ or an ‘identifier component’.
If an Identifier consists of only a single Attribute, then it has only one Identifier Attribute which constitutes the complete Identifier. Such Identifiers are informally called ‘single attribute identifiers’.
Identifier.Class and Attribute.Class — The Identifier is in the same Class as the component Attribute.
Identifier.Domain and Attribute.Domain
- Identifier + Attribute + Class + Domain
Standard Mx:Mx composition of an association class identifier with the Class and Domain attributes individually merged.
Attribute is required in zero, one or many Identifier
Identifier requires one or many Attribute
By definition, an Identifier consists of at least one Attribute. An Attribute may or may not be part of an Identifier. And it is possible for an Attribute to be a component simultaneously of multiple Identifiers. (There are numerous examples of this in the miUML metamodel itself).
An Attribute is independent when its value is not derivable from the values of other Attributes in the same Domain at a given slice of time. An Independent Attribute may, however, be updated based on changing circumstances such as state changes, class collaborations and domain interactions, such as a command from a user interface domain, for example.
- Name + Class + Domain
Same as the superclass.