The Design Pattern Toolkit

Design Pattern Toolkit

The Design Toolkit (DPTK) is an Eclipse plug-in that can apply a transformation to an arbitrary model to generate multiple Eclipse resources of multiple types. The toolkit has a runtime component for -based generation as well as a tools component that supports transformation authoring and management. Each DPTK transformation has a Model-View-Controller structure and is used to generate a class of applications (data base beans, J2EE applications, Eclipse extensions, etc.):

The model is an implicit schema that describes the information which is unique to the application being generated (e.g. property names used in a J2EE application's Java beans, HTML input forms and HttpRequest parameters). While each application has its own unique application definition (appdef), the appdefs for a class of applications all adhere to the schema that exactly describes what information is required in order to build an instance of that class of applications.
The view is a collection of templates that contain the static common content of the Eclipse resources to be generated. Embedded in each template are template tags that direct the generation and insert data from the appdef into the generated output.
The controller is a small set of specialized templates that control the number of times each pattern template is applied.

Transformation users provide a populated model (usually an XML file) that conforms to the pattern's schema and apply the transformation to generate an application consisting of a number of Eclipse resources across multiple Eclipse projects. Once the transformation is complete the appropriate build and validation actions are performed automatically

The templates (both view and controller) for a transformation can be read from a number of locations. An Eclipse project with a DPTK nature can hold templates for rapid edit-transformation iteration. When debugged and stable, a transformation can be exported as a "PatZip" file and can be used in that form by other users. If the transformation is used by an Eclipse plug-in, the patzip file can be deployed with the tool and should be named in an extension in the tool's plugin.xml file.

Development and Distribution of Intellectual Capital

While the Design Pattern Toolkit is useful for quickly generating "tedious" components (JDBC beans, LDAP import files, etc.), its primary value to an organization is its ability to help develop and disseminate intellectual capital (best, current and only practices in the development of applications). While many developers feel that they have great leeway in the design and implementation of J2EE applications, fat clients, web services, portal applications, etc., in practice the runtime API set, performance requirements, separation of concerns (not requiring too many skills to develop a particular artifact), team development considerations, the need for application designs that scale arbitrarily and other local development conventions and practices all combine to restrict the design and implementations of these applications. In fact, aside from a few minor style variations, there almost always turns out to be a single best way to implement an application for a given development shop and a given set of application requirements. Unfortunately for most development organizations, that only or best way to implement applications is only understood by a few technical leaders as an art. The DPTK helps those technical leaders develop that art into an automated science that's usable by all members of the organization.