Leonardi Framework

Leonardi is an open source, model-driven software framework that allows implementing graphical user interface oriented applications. Leonardi is the copyright of the French ISV Lyria.

Principles

Leonardi is a framework based on a model describing the information system. This model is enriched with both presentation specific information and data connectors. Next, business specific rules and behaviors can possibly be added using the Java language. Eventually, the application is deployed, either as a DHTML/Ajax GUI, an Eclipse (software) plug-in, an RCP or a Swing (Java) desktop application.

The originality of Leonardi is twofold. First, the framework applies the concepts of Model-driven engineering to the specific field of GUIs. Second, its execution engine allows dynamically generating, at run time, the screens trequested by the end-user, based on the current status of the data that is dealt with.

The Leonardi business model contains connector specific configuration, which indicates where data persists and how to cache it. Standard connectors include flat files, various DBMS, Corba, EJB or LDAP. The model also includes the concept of display manager, that allows deploying the software in different types of graphical environments (Web Ajax, Swing, SWT, Eclipse RCP…).

On the one hand, Leonardi differs from 4GLs by offering richer functional features for user interface purposes, which allows it to be used in management systems as well as in technical applications. On the second hand, Leonardi is different from the traditional software environments that implement the MDA approach by not generating code. Instead, the engine executes the model on the fly, addressing the three MVC layers (Model, View and Control) classically dealt with in GUI applications.

Leonardi is often used as a RAD tool, but it also addresses the needs of application migration and modernization, by providing a technology independent approach. It can also be used in more complex projects. It is fully based on underlying Java and XML technologies and consists of an extensible environment. In its latest release (V4.0), Leonardi is licensed under the terms of the GNU General Public License (GPL).

Use

Leonardi fits various computer based information systems related contexts: RAD, application migration or complex projects. It is used in different sectors, including defense and security, transportation, energy, industry and telecommunications.

Leonardi is provided with a Studio tool that can be used to create the business model, or discover it from an existing structure. It can also generate specific DBMS schemas and includes, in release V4.0, a graphical builder.

Leonardi is licensed under the terms of the GNU General Public License. Lyria also sells value added packages of Leonardi.

See also

*Graphical user interface
*Model-view-controller
*Eclipse (software)
*List of Eclipse Modeling Framework based software
*Ajax (programming)
*Model Driven Engineering
*Model-driven architecture

External links

* [http://www.lyria.com/ Official website]
* [http://www.lyria.com/IMG/docs/01_QuickStart_Leonardi.pdf Article: “Develop a Client Application with the Leonardi Framework”]