Re: EJB + Cocoon, "Best Practices"

[Joerg Heinicke <jh...@virbus.de>]

Reinhard Poetz wrote:
> From: Joerg Heinicke
> 
>>Not until now though it was planned and we finished work 2 
>>months ago. I 
>>know we have a presentation system, which is normally not 
>>reachable from 
>>outside. I will ask the /decision-makers/ tomorrow :-)
>>
>>Thanks for your interest,
>>
>>Joerg
>>
>>PS: Reinhard also asked some time ago when we haven't finished it.
> 
> 
> Yep, I was very impressed by that you showed me. It's also the first
> business application that uses XUL. So the work of your company could
> encourage many people using XUL - in the future XUL is an equivalent
> possibility how to create the UI.
> 
> Reinhard

IIRC you only have seen the help :-)

Now you can see the real application from the users view:

url:       http://conweb.virbus.de/
login:     cocoon
password:  usingxul

*Before* you can use it, you unfortunately have to prepare your Mozilla. 
This is because of the default security restrictions of Mozilla, where you 
are not even asked if you want to grant permissions to scripts to access the 
XPConnect object. Adding a user.js to your Mozilla profile (do you know 
where to find it?) that contains the line (or simply adding the line to an 
existing user.js)

user_pref("signed.applets.codebase_principal_support", true);

changes this behaviour (after a Mozilla restart) and you are asked to grant 
permissions. The XPConnect object is needed for access on RDFDataSources. 
(See http://www.mozilla.org/rdf/doc/faq.html#rdf_examples for more 
information. There is something written about this line.)

Furthermore Mozilla's bugzilla already contains a bug at this topic for 
simplifying this handling in the future: 
http://bugzilla.mozilla.org/show_bug.cgi?id=122846.


The application itself:

It's a controlling tool for (not only) venture capital companies. The work 
was done before using Excel sheets, now with a self developed J2EE component 
WebSheet, the ConWeb application (also J2EE) in the backend and the XUL 
application in the frontend.

So this application should replace Excel ;-) The sheets can be exported in 
PDF and Excel.

Though the application is completely i18n-ed, the application is only 
available in German at the moment. There is also an online help (with an 
additional context sensitive mode), but this is in German too. (It is also 
available outside the app, but with some JavaScript errors then: 
http://conweb.virbus.de/conweb/conweb/help.xul. This is what Reinhard 
already saw IIRC.)

The usage of Cocoon is relative low, but effectively. (I'm working on a 
Struts app with JSP at the moment and I really don't love it.) It delivers 
all resources, does the transformations and serializations, so it only 
handles the view. The connection to the backend is handled by an 
EJBConnectorAction and a FilterGenerator.

The advantage of XUL are the static pages, every user in every role gets the 
same static XUL files. They are personnalized through RDF and CSS. For 
example an admin has more tabs as you can see in one screenshot in the help. 
With the RDF and the template mechanism, the data can be easily updated 
without updating/reloading the XUL files. You only update the data.

The app is based on Cocoon 2.0.4, JBoss 3.0.6 and Tomcat 4.1.18. We switched 
off Cocoon's caching completely, because of the bug 
http://nagoya.apache.org/bugzilla/show_bug.cgi?id=17924 for the static 
resources and our non-cachable generator (the caching is prepared in the 
FilterDocuments, but the generator does not handle it at the moment). This 
gave us a big performance improvement (from 600 to below 100 ms for a simply 
sheet).

I hope I have not written to much ...

Regards,

Joerg

-- 
System Development
VIRBUS AG
Fon  +49(0)341-979-7419
Fax  +49(0)341-979-7409
joerg.heinicke@virbus.de
www.virbus.de