Introduction to UML
- UML is a graphical language for object oriented modeling
- UML is short for Unified Modeling Language.
- UML is developed by the Object Management Group (www.omg.org)
- UML version 2.4.1 is an internasjonal standard numbered ISO 19505:2012.
The graphical language consists of diagrams with graphical model elements. In addition, a modeling tool will store textual definitions of model elements. If the graphic language is not enough, one may also enter keywords and restrictions in their own precise textual language.
UML has many different kinds of diagrams to describe information, behavior, use cases and components. Geographic information is described mainly with 3 diagram types for static structure:
- Package diagrams shows packages and relationships between them.
- Class diagram shows the classes and associations between them. Class diagram shows the classes' names and attributes.
- Object Diagrams can display real instances that describe the real world.
The diagrams show the different types of model elements graphically.
- A UML package is a container for a group of elements, and is represented by a tabbed folder in package diagrams.
- Package dependencies shows that classes in one package need classes from another package. This is illustrated with a dashed arrow, pointing to the package which the other package is depending on.
In the diagram below, the package Lineage information contains classes that need classes from the package Citation and responsible party information. More specific - several classes in Lineage information have attributes with data type CI_Citation, which again is defined in Citation and responsible party information.
