A
while ago I worked on an Oracle Portal project, that
was based around a menu calling a number of
Discoverer workbooks and other reports. The menu was
a portlet that was located on the left-hand side and
took up around a quarter of the page. The right-hand
side was a portlet that contained whatever workbook
or report had been selected using the menu.The
design approach we took was to use something called
the
'model-view-controller' design pattern as the
basis for our application. Model-View-Controller, or
'MVC', is a way of building an application so that
the data store, the business logic and the
presentation logic are kept separate, with the aim
being that it's easy to upgrade, extend or swap
parts out without affecting the rest of the
application. MVC is usually talked about in the
context of Java development, but it's more of a
concept than a Java-specific technology and in our
case we actually built the application using PL/SQL
portlets.
For this application, the model was the Oracle
database, with a schema containing menu entries and
of course the underlying database on which reports
were run. The controller was the menu portlet, and
the view was the main portlet that displayed the
reports. The menu portlet contained menu items and
hyperlinks which, when clicked on, reloaded the page
and passed a parameter to the view portlet, which
then decided which report to retrieve and display it
in an IFRAME. Each menu item in the controller
portlet had the same format (the portal page URL,
with a 'report_id' parameter) and the view portlet
just used a CASE statement to display a report from
a list of possible reports.
Anyway, where this is all going is that Oracle
have recently announced (link via
Tim Burns' weblog) support for MVC portlets, and
Apache
Struts, through the
OracleAS Portal Developer Kit. Apache Struts is
a java framework for building model-view-controller
applications, which in this case would be built
using Java Server Pages and deployed as OracleAS
Portlets. It's java rather than PL/SQL, but it's a
pretty comprehensive framework and not all that
difficult to set up, especially seeing as much of
the portlet element of a JSP can be generated
automatically by JDeveloper's portlet wizards. If
you're building a portal application using JSPs it's
worth checking out the struts support as it's an
easy way to use the MVC design pattern, and it's a
relatively low-cost exercise to add one or more
portlets to an existing JSP and servlet application
by defining the portlets as additional views.
For more information, take a look at:
and include the URL for the page.
