AEGIS/cgi includes all the regular features of AEGIS, including the AEscript Program Language, and adds Internet-specific extensions such as:

• Automatic HTML formatted output: output of PRINT function calls is automatically formatted as standard web text
• Templated output, called FlyPrinting, allows output pages to be designed using your favourite HTML design tool, then have data values dropped into the holes on-the-fly as the form is sent back as output to the browser
• A powerful Session Management facility, allowing serialized atomic interactions to be threaded together into a cohesive application
• Session Security Keys allow encrypted validation (with user defined time-outs) that one action is properly invoked by a previous trusted script
• Easy access to URL and Form Variables: all CGI inputs appear in the AEGIS variable namespace
• Easy access to CGI Variables including the Browser and Referer headers

Session Management

One of the most difficult tasks in building CGI applications is the atomicity of each interaction. A single HTML form or page leads to a CGI script, which then produces more HTML output. However, that's only one interaction -- and that's all that a standard CGI tool provides you. There's no way to link the next action into it, and a true application is not just a single screen -- it's a cohesive network of menus, screens and reports, all building on the processing completed by previous programs in the application suite.

This is where the Session Management features in AEGIS/cgi transform an ordinary CGI program into an extraordinary application building block. A call to the SESSION() system function returns a unique, time-limited, encrypted security key, which can be passed back in the HTML output, usually as a hidden form variable. This key is presented to the next CGI script, which reads it, validates it and decodes it, to ensure that the time limit is honoured and the originating session was valid.

This is further enhanced by Session Variable Persistence. Any AEGIS variable value can be saved to the Session Context. The variable will be permanently associated with the unique session key, and any subsequent script which references that key will automatically have access to all saved variable values. If that script generates another session key for future use, those variables are maintained in the new session context as well.

These features solve the most difficult problem in CGI Application Development: how to knit each single script together into a cohesive application. FOR INSTANCE: your users can log in once, at the beginning of their session, and the results of that login are securely saved to the session context. Each subsequent script is assured that the information it receives is valid and current; in other words, that the user has properly logged on. As users navigate through the application, the common information about the user and what they are doing travels with them, from form to form and from script to script. All without cookies, time-consuming database lookups, or passing a zillion variables on the URL line (a significant security risk for hacking and the disclosure of unwanted secrets)!

Session Management can transform a simple web form into a powerful application, made possible through AEGIS/cgi 's powerful, rich environment. Try it today - once you experience the power, you'll never write Perl or shell scripts again!