Overview of patterns

What is a pattern?

A pattern is used to address a recurring design problem, and provides a tried and tested solution resulting from solid design experience.

The use of patterns is generally considered a sound practice in software development circles. Patterns ensure the presence of certain characteristics within the developed system, such as reusability, progressiveness and ease of maintenance.

Patterns and Objecteering MDA Modeler

Objecteering MDA Modeler provides a set of services used to support patterns in development projects. These services allow users to specify, test, package and apply patterns to models. Patterns can be also imported into and exported from MDA Modeler.

Objecteering MDA Modeler supports the definition of patterns through the modeling of UML diagrams and the representation of parameterized elements. The package merge mechanism, as defined within the OMG UML2.0 standard, is the foundation of the pattern mechanism. Objecteering Software has extended this mechanism, in order to support further capacities, such as element deletion. Objecteering MDA Modeler allows the user to simply and rapidly define and automate patterns, simply by using UML modeling.

A pattern in MDA Modeler is a UML package template. As a reminder, a package template is a package which is defined based on a set of parameter elements (template parameters). These template parameters can be classes, interfaces, data types, enumerations, attributes, operations, association roles and packages.

Working with patterns in MDA Modeler

The following pattern-related features are described in the following sections of the current chapter of user guide:

· Applying patterns

· Creating patterns

· Modeling pattern solutions

· Expressing pattern constraints

· Expressing pattern actions

· Exporting patterns

· Importing patterns