Introduction

The Rule based Swing applications includes a rule base generating forms form OWL ontologies. This rule base is designed to run with other GUI API's than Swing, like Java bindings to Qt, GTK, etc. There is a compatibility layer based on an ontology for generic GUI's.

However, it has never been used for anything else than Swing. A Web example is particuliarly interesting to develop a rule-based Web application with domain plus applicative logic.

The ingredients

We considered several object oriented Web page frameworks: GWT, Echo 3, Apache Wicket. The latter looks the most promising, because a part (only) of the HTML page can be managed by the Web page framework, and thus by the rule engine. Look at this, pasted from Apache Wicket introduction :

But Wicket applications are not like applications written in either Tapestry or Echo, because in Wicket you get the best of both worlds. You get the benefits of a first-class component model and a non-intrusive approach to HTML. In many situations, this combination may prove to be a significant development advantage.

Recipe

install EulerGUI sources and build (uses Maven)

download Déductions project rules and samples:

svn co https://deductions.svn.sourceforge.net/svnroot/deductions

run with EulerGUI this project :
```
deductions/n3_nojs/person-app.n3p
```
( see here for details : Running the project with imported Déductions rules )
open this file in the swing3.n3p rule base:
```
deductions/n3_nojs/generic_to_java-rules.n3
```
It has a bunch of rules to generate Swing objects and adapt predicates representing method calls, like:
```
{ ?W a gengui:TextField.
  javapr:thisApplication app:platform app:Java .
} => {
  ?W a java:javax-swing-JTextField } .
```
The highlighted URI representing classes have to be adapted to Wicket ( or Echo 3). Copy the original file as generic_to_wicket-rules.n3 .

Save a copy of the swing3.n3p rule base with generic_to_wicket-rules.n3 as wicket.n3p .

Save a copy of the person-app.n3p project with wicket.n3p instead of swing3.n3p as person-app-wicket.n3p .
follow Wicket's Quickstart (uses Maven)
( you may want to use richer Maven archetypes : More archetypes )
Call from Wicket Quickstart Java code the EulerGUI API ( see "Running a stateful Drools engine" ), to open the modified project person-app-wicket.n3p you just created .
Restart the Wicket Quickstart web server ; you should see the same generated form as the Swing project :