Abstract:

The construction of information systems involves a considerable 
amount of technicalities that are only slightly related to the 
business logic of the system. The WebSI framework for construction 
of Web-based information systems was designed with progr amming 
abstractions attempting to minimize the amount of technicalities, 
that the programmers have to manage. WebSI automatically manages 
technicalities related to database access, security, Web and user 
interface. The graphical user interface (GUI) is gen erated 
automatically from semantic specifications, e.g., enabling the 
user to select a single item out of a set of items is coded with the 
method 'inputChoiceOneOfN(...)'. This method produces a GUI for 
selecting one out of n; it may be a menu or some alternative, e.g. 
a set of radio buttons. The programmer need not specify the shape of 
the produced GUI, its size, colors, font types etc. As a result of this, 
the code to be written regards to some extent only the flow and processing 
of the data, i.e., the es sence of the information system. This approach 
saves coding and enables the programmer to focus on the semantics of the 
applications. Students using WebSI in our labs could therefore produce 
better projects than in comparable labs. A high level programmin
g abstraction leaves the programmer few parameters for fitting the GUI 
to specific needs. The degree to which WebSI could produce satisfactory 
GUIs will be illustrated.