Building Web Applications with WebHub
By Erik S. Peterson
Web applications are interactive Internet applications that use HTML as their user interface. Anything that executes on the client side may be part of a Web application, or Web app, but these include server-side programs that dynamically create HTML pages and synergize other Internet technology such as Java applets, ActiveX controls, GIF files, VRML, and SMTP. By applying Internet technology to existing data resources, companies can avoid multiple client installs, resulting in lower maintenance costs and less per-client licenses.
For example, I recently converted a Windows-based OLAP (Online Analytical Processing) application to a Web application. The original application required that the EXE and support software (database DLLs, OCXs, and so on) be reinstalled for every new user or version upgrade. Now that it's a Web app, users need only a Web browser and a URL to get the same OLAP features.
In this article, I'll explore the general architecture and features of a Web app and examine one of the several available products for creating dynamic Web content:
WebHub, from HREF Tools Inc., a Web app toolkit for Delphi and C++ Builder.
Web app Architecture
Building a Web app requires the following:
Maintaining state. Because HTTP is a stateless protocol, state information must be maintained while the surfer navigates your Web site.
