The 'd4' demo is an interactive application, developed for customer service, orders, and printing various reports. The source code of all modules and forms of the application is written in Informix 4GL programming language. Source code also contains expressions and constructions frequently used in 4GL.
In the main menu you can add, edit, browse and delete client information, orders and generate various reports.
In the Customer tab of the main menu, you can add, edit and delete customer data. It is possible to add data for one client as well as for several clients in a row. In this tab you can also search and browse through the client list. To enter search criteria use the fields of a client data form. If several clients are found, you can use scrolling (buttons - 'Next'/'Previous') to browse through them. After clicking "Select" on a client, you can edit or delete client data. Before deleting a client, you should delete the orders of the client.
In the "Orders" tab of the main menu you can add, edit and delete customer orders. You can also search and browse through the orders in this tab. To add, edit or delete an order, you should find and select the customer. After selecting the customer (use the Select button) you can perform a relevant action. If the order was added correctly, the invoice will appear on the screen. To browse through customer orders, you should also find and select the customer first. After selecting the customer, the customer's orders will be displayed on the screen. If several orders are found, you can use scrolling (buttons - 'Next'/'Previous')to browse through them.
In the "Report" tab of the main menu you can generate various reports. In the "Options" submenu you can change report output destination.
Structurally wise, d4 demo application consists of seven 4gl modules and four per forms. The application uses Informix database.