[Eulergui-user] extension point capabilities of EulerGUI

[Jean-Marc V. <jea...@gm...>]

Hi

With Revision 2980<http://eulergui.svn.sourceforge.net/viewvc/eulergui?view=revision&revision=2980>,
the extension point capabilities of EulerGUI are used for real.
Now the result display features are set by N3 configuration rules in
src/main/resources/eulergui/gui/controller/application-rules.n3<http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/src/main/resources/eulergui/gui/controller/application-rules.n3>

These result display features are displayed by 4 buttons on upper right
corner of main window, and are implemented by there classes:
ResultEditorAction, ResultEditorN3Action, ResultGraphvizAction,
ResultTableAction

There is just one rule to configure these features :

{
  ?GUI a java:n3_project-ProjectGUI
  ; javap:resultManagement ?R .
} => {
  ?ResultEditorAction a java:eulergui-gui-actions-ResultEditorAction
  ; javam:setProjectGUI( ?GUI ).
  ?ResultEditorN3Action a java:eulergui-gui-actions-ResultEditorN3Action
   ; javam:setProjectGUI( ?GUI ).
  ?ResultGraphvizAction a java:eulergui-gui-actions-ResultGraphvizAction
  ; javam:setProjectGUI( ?GUI ).
   ?ResultTableAction a java:eulergui-gui-actions-ResultTableAction
; javam:setProjectGUI( ?GUI ).
  ?R
    javam:addAction ( ?ResultEditorAction )
   ; javam:addAction ( ?ResultEditorN3Action )
   ; javam:addAction ( ?ResultGraphvizAction )
  ; javam:addAction ( ?ResultTableAction )
}.

This rule says : "for each main window ProjectGUI, with a field
resultManagement ?R, create the 4 objects ?ResultEditorAction ,
etc, and add them to ?R through method addAction".

The method addAction on class ResultManagement is just one of 10 extension
points that are planned :
http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/architecture.html#L762

In the Roadmap for EulerGUI  2.0 :
http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/documentation.html#L9989

this task is described this way :

Features

and code changes
CommentsEstimate

(skilled developper)
Sub-feature

*extension points* for adding features in N3 configuration filewill also
enable many things: user defined extensions point à la eclipse; several
user modes ; this will also be similar to Spring configuration, but with
possibly platform and context -aware rules here; estimation just for
creating interfaces and containers in Java2new N3 sources types: RDFa,
ATTEMPTO sentences, ng4j / semweb
client<http://www4.wiwiss.fu-berlin.de/bizer/ng4j/semwebclient/>


Note that the main architectural advantage of extensions point à la
eclipse<http://wiki.eclipse.org/FAQ_What_are_extensions_and_extension_points%3F>is
to be able to add a feature without modifying a line in the Java code.
But here, contrary to Spring or eclipse stuff, we have the whole power of
rules here: it is possible to take in account machine and user context and
history.
This mechanism is usable also in applications built with the EulerGUI
framework<http://eulergui.svn.sourceforge.net/viewvc/eulergui/trunk/eulergui/html/documentation.html#L7038>
.

CAVEAT:
- no support for checking Java methods and classes is provided in EulerGUI
editor, and error here raise Drools compliation errors that are not
user-friendly
- the above rule N3 file is accessible to EulerGUI through the classpath,
so to modify the internal rules, one must rebuild EulerGUI (or work in
eclipse).


-- 
Jean-Marc Vanel
Déductions SARL - Consulting, services, training,
Rule-based programming, Semantic Web
http://jmvanel.free.fr/ - EulerGUI, a turntable GUI for Semantic Web +
rules, XML, UML, eCore, Java bytecode
+33 (0)6 89 16 29 52
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