Chapter 8. WebSphere and XML approaches 167
numbers, aircraft types and arrival and departure times and also passenger
details names, membership number and the flight to be t aken.
The database has been kept simple. We could have used other more complex
mechanism to query the database, but chose to u se the wizards within
Application Studio.
8.3.1 Solution Outline
As in all applications, we are a clear distinction between the Graphical User
Interface, the Web Tier and the Data Source(Figure8-1). The advantages of
these delineation are obvious. If the tier were loosely coupled, they c ould be
reused to interface with other components of different applications. The Client
interface could easily have been implemented using JSP, ASP or even
Javascript. Although we have generated HTML, we could easily have generated
a display for a PDA or a mobile phone, just but changing the XSL styleshe et.
Similarly, the data server could be any database that was available where
proprietary or open source. The invocations for data access, SQL queries, stored
procedures could be in the Web Tier with the queries and procedures in the data
server. In our Web Tier, also we have used XSLT to transform the XML data.
The Web Tier is the major component, and with time, this too could be further
delineated within itself. As transformers, validators and parsers incorporated
newer versions of XML and Schemas there would be further modularization in
this area.