by Rosana T. Vaccare Braga     Advisor: Professor Paulo Cesar Masiero

University of Sao Paulo - Brasil Finantial Support from FAPESP grant  98/13588-4

Introduction

I have developed a Pattern Language for Business Resource  Management, called GRN, which guides the development of applications in the business  resource management domain. This includes applications for renting, trading or  maintaining resources as, for example, videotape rental systems, libraries,  hotels, retail stores, electric appliance repair shops, car repair shops, etc.  You can download the pattern language here.

Based on this pattern language, I've built a  framework to support the development of applications in this domain, called GREN  framework . Cincom VisualWorks for Smalltalk  is being used in its implementation. Objects are stored in a MySQL database.
 

Now I'm building a Wizard to support GREN instantiation, called GREN-Wizard.

The GREN Wizard

GREN Wizard is a tool that helps instantiating the GREN framework for Business Resource Management  (Gerenciamento de Recursos de  Negócios, in Portuguese).
The wizard was designed so that framework users need only to know the GRN Pattern Language in order to obtain the Smalltalk code for their specific applications. So, the interaction with GREN-Wizard screens is similar to using the GRN Pattern Language. You will be asked what patterns to use, what variants are more appropriate to your specific application, and which classes play each role in the pattern variant used. After, you will be offered several choices to proceed with the application of other patterns of the GRN Pattern Language.
 

Figures 1 and 2 show some of the GUI screens for the GREN Wizard

The GREN Wizard goal is  to support GREN  instantiation for specific applications. The application developer uses this  wizard in parallel with the pattern language application, supplying information  concerning the variable aspects of the framework. Then, the code of his  application is automatically generated, together with a script for tables  creation in the MySQL relational database.

To model an application, framework users will follow the GRN pattern language. They will make several analysis decisions while using GRN (for example, the use of sub-patterns or variants)
As the Wizard GUI was designed based on the GRN pattern language, it is easier to adapt the GREN framework for a specific application.

Characteristics:

• interface is compatible with the GRN pattern language
• the history of the GRN pattern language usage is saved and can be reused for similar systems
• the text of the GRN pattern language is supplied to support the framework user
• it can show a list of the patterns already used in the instantiation of a particular application

The objectives of the GREN Wizard are:

• automatic generation of the specific application classes, inheriting from the appropriate framework classes
• automatic generation of the specific code for the new classes, including new methods and automatically compiling them in the correct classes.
• automatic creation of the relational database and corresponding tables
• automatic creation of the application menus

Figure 3 - Structure of the metadata associated to the GREN wizard

The developer can adapt the resulting code for requirements not included in the framework, and, to do that, he can use GREN documentation, which consists of class diagrams, class hierarchies, description of hot-spots and a cookbook for manual instantiation.