For eight years, Janko Mivsek has been working on combining Object oriented technologies approaches with Internet technologies at constructing information systems in different areas, such as finances, logistics and managing supply chains. He developed his own server for constructing web applications - AIDA/Web, which has become a basis for a series of his and other company's products. He is regularly attending various events, like conference on Object oriented technologies in Slovenia, Days of Slovene Information science, ESUG conferences (European association of Smalltalk users) and OOPSL.

Subject

AIDA/Web, application server

AIDA/Web is a web application server, which means it is also a framework for producing web applications that build web pages dinamically. Each such server has to ensure at least the users' identification and their right to access, managing users' sessions and security policy. It is also important for the programmers to have a proper environment for fast and simple web site building with programming in a language they are usually using. It is not necessary for them to bother with an extra web page language HTML.

AIDA/Web satisfies all the mentioned needs with its strong framework, made in Smalltalk language. The language is objective, therefore the web page for Aida is an object, constructed of sub-objects, such as web page elements. These can be combined into components applicable also on other pages. It is obvious Aida preserves its objective attitude also when building web pages and applications. Besides, Aida is very helpful when connecting web pages with hypertexts. Namely, it creates those links automatically, because the web link for Aida is usual reference (pointer) between objects in objective model. Its moto is the following: each object can be introduced as a web page and links between objects are links between web pages.

One of Aida's important qualities is a strict division of software, dealing with presentations and the software in charge for the functionality of an application. This attitude is called MVC (Model View Controler) ever since Smalltalks birth and is lately effective also in the world of Java. Just think of Struts. By dividing in accordance with MVC we accomplish the function logic of the system is separated from the introductory level, which is in many cases more complex and demands more code. When not separated, it is so to speak lost among the introductory code and the consequence is aggravated maintenance and functional development in the future. The mentioned problems occur, for example, when making pages with ASP, JSP or PHP.

In the end we need to dedicate few words to experiences and fields of usage. Aida was developed already back in 1996 and has since then been running quite some public as well as private web sites. One of the famous is mountaineering site, called >Gore - Ljudje< ( www.planid.org ), ran by Aida since 1999. This site includes common - static web pages as well as more dynamical part, above all discussions, browser, real time statistic and more. Because of its direction to highly dynamical web pages, it has been present in many business applications, used within companies in the frame of intranet. Some of them are: Earth gas account (AIDA/GBS), gas supply management network (AIDA/GMS), storehouse operations and transport (e-logis).

Aida is available in open source, accessible at www.eranova.si/aida . Since it is written in Smalltalk, it can be transferred to various operating systems, from Windows, through different Unix systems to Linux.