The "State" Problem

The CGI interface provides a simple, effective solution for posting and retrieving information to and from Superbase. However, there is one major problem with any CGI implementation: The web-server sends only a limited amount of information to the executable locations of the output HTML file, an .INI file with system settings, and an .OUT file containing the contents of the current posted form. Unfortunately there is no way for the application to know about previous forms, settings or values. For example: suppose you have an initial log-in form prompting the user for a name and password. It is sent to Superbase where the program processes the request. At some time in the future the browser submits a second form (say company, phone, address, etc.) and you need to know what user is "logged-in". With CGI this isn't possible because the only information the web-server passes along is the current form submitted previous values are lost.

You cannot use global variables to track information, since you may (and likely will be) processing requests from multiple users in any order. Some CGI implementations create hidden fields on each form, such that values are re-submitted with every form element. However, not only is this system awkward for programmers to implement, but also it forces every page to contain a form, and every single form element to contain dozens (or hundreds) of fields which must be re-submitted with every request. As the complexity of Internet applications increases this solution quickly becomes impractical.

GeoMetrix has developed a DLL and series of Superbase routines for handling this problem by storing each form value as it is submitted by each user. The system automatically keeps "state" by returning values explicitly for the current user. This mechanism is currently employed in the Superbase Internet Server.