Download Java And XSLT

Figure 7-1. Discussion forum screens
Creating a graphical layout of the web pages as shown here is sometimes called storyboarding, a
common user interface design technique that has its roots in the animation, television, and motion
picture industries. Such high-level diagrams typically start as hand-drawn sketches on paper, with
the intent of capturing the overall application flow. This is a good place to start because it shows
how everything fits together without delving too deeply into technical design details.
The "Discussion Forum Home" page is the starting point and displays the list of all message
boards. For each message board, a list of months with messages is displayed. From this screen,
the user can either click on a month to view a list of message subjects, or click on a link to post a
new message. The user can always return to the home page from any other page in the
application.
The "View Month" page shows message subjects for a particular month in a given board. These
messages are displayed in a tree that shows the message subject, author, and create date. The
structure of the tree represents threads of discussion, with replies indented underneath the
original messages. From this page, the user can either select a message to view or click on a link
to visit the "Post New Message" page.
The "View Message" screen shows details for an individual message. From this page, visitors can
either return to the month view or click on a link to reply to this message.
The final page allows users to either post a new message or reply to an existing message. Since
posting and replying are quite similar, much of the Java and XSLT stylesheet code is reused.
Although using the same code for multiple web pages reduces the size of the application, it can
add complexity because the code must be capable of two modes of operation.
7.2 Prototyping the XML
Once the requirements and screen flow are well understood, it is possible to move on to a more
rigorous design process. Web sites based on XSLT are highly modular, facilitating a design and
implementation process that can be farmed out to several members of a development team. Each
piece can be developed and tested independently before finally bringing everything together into
the completed web application.
7.2.1 XHTML Prototypes
Creating user interface prototypes is an early task that can be handed off to less experienced
programmers or perhaps to a dedicated web page designer. At this stage in the game, an overly
complex and graphical web interface is not required. The bells and whistles can be added later by
merely updating XSLT stylesheets. In fact, too much effort at this early stage can make it more
difficult to figure out what the XML and XSLT should look like.