M2 UML Class Diagram

A metamodel for UML class diagrams — the most widely used notation for modelling software structure, data models, and type hierarchies.

Element Types (4)

Classifiers Layer

Type	Shape	Colour	Description
Class	rectangle	#B5D4FF (light blue)	A UML class with name, attribute, and operation compartments
Interface	rectangle	#D4E8FF (lighter blue)	A UML interface — a contract defining operations
Attribute	rectangle (subordinate)	#D4E8FF	A typed property owned by a Class. Renders inside the attributes compartment
Operation	rectangle (subordinate)	#D4E8FF	A behaviour owned by a Class or Interface. Renders inside the operations compartment

Compartments

Class renders with three compartments:

1. Name — class name in bold
2. Attributes — owned Attribute elements displayed as {name} : {Type}{Visibility? [{Visibility}]:}
3. Operations — owned Operation elements

Interface renders similarly but with a <<interface>> stereotype.

Properties

Attribute:

• Type (enumeration: String, Integer, Real, Boolean, Date, DateTime, Text)
• Visibility (enumeration: public, private, protected, package)
• Is Static (Boolean)

Operation:

• Return Type (String)
• Visibility (enumeration)

Relationship Types (5)

Relationship	Line Style	Markers	Description
Association	solid	none	General connection between classifiers
Composition	solid	filled diamond at source	Strong ownership — part is destroyed with the whole
Generalization	solid	hollow arrow at target	Inheritance / “is a”
Realization	dashed	hollow arrow at target	Implements an interface
Dependency	dashed	arrow at target	One element depends on another

Enumerations (1)

UML Visibility — public, private, protected, package

Export

UML models can be exported to XMI 2.5.1 via File > Export XMI and to Eclipse EMF (.ecore + .xmi) via File > Export for Eclipse EMF.