idge, running on the Web server instead of the client. The end user's Web browser loads an HTML page with an HTML link to a Java applet on the Web server, as in the following:
<APPLET codebase="/webform/" code="oracle.forms.dsp.CfmDispatcher" width=710 height=400>
<PARAM name="server" value="server module=FMX_file_path"></APPLET>
You supply the virtual directory (
"/webform/"
), the server name (
"server"
), and the name of the Developer/2000 module file accessible to the Web server that you want to run (
FMX_file_path
). This module file and any modules that it calls are compiled for the Web server's OS.
The applet is a generic Developer/2000 display driver handling all the display requests from any Developer/2000 application. Oracle has obtained 100 percent Java certification from Javasoft for this system. The applet establishes a connection to the Web cartridge, stores its widget library in the Java cache on the client, and gets out of the way. The Web cartridge handles all requests from the Developer/2000 module for display by sending requests to the Java widgets running on the Java virtual ma
chine in the client browser. It also handles the connections to the database server, which may be running on a separate machine somewhere else on the network. The cartridge is a SQL*Net client that sends SQL to the database server and gets back data.
From the point of view of Web users, they click on a link in a standard Web page and see a client/server application frame open up. That frame lets them interact with the database server just as though they were a DBMS client application.
Developer/2000 for the Web thus has a true three-tier architecture: the browser as client, the Web cartridge as applications server, and Oracle7 as the database server. This architecture will become more flexible when Oracle8 and other products are available, bolstered with support for Java beans and other distributed-object technology.
Developer/2000's Web-Friendly Architecture
