Re: Longwell, Semantic Bank, Fresnel

From: Ryan Lee <>
Date: Mon, 27 Feb 2006 17:15:24 -0500

Zak Mc Kracken wrote:
> Hi All,
> I've studied a little bit Longwell and things around it. Sorry, maybe
> mine are silly questions, and sorry for the length of this message, but
> I feel a bit like on raft in the middle of the ocean...

By all means, ask away.

> I have an OWL model of an application domain
> (
> I'd like to build my own simple editor/browser of this information,
> either by modifying Longwell code (or Semantic Bank or ...?), or using
> some lower level code, such as some implementation of Fresnel, that I
> could invoke from a servlet of my own, or from a a Java class, the alike
> way it's possible with Velocity templates, or with XML/XSL transforming.
> More precisely, I imagine my code fetches some RDF (or some URIs) and
> then pass it to Fresnel templates (lenses, selectors etc.), for the
> rendering, and eventually I have back some HTML to be output (ideally: a
> result type of String or a StringWriter/JspWriter filled with HTML).
> I would prefer to code things this way, because it doesn't seem that
> Longwell architecture fit the kind of visualization that I want, that is
> quite dependent on the type of class being shown, and often the model
> "Subject-->Properties" is not so appropriate (BioDASH,
>, is a similar example,
> where the visualization model needs to be rather flexible).

This is true in Longwell down to its core as it's one base we decided to
work from. But it's also true in Fresnel Core - choosing lenses and
formats is almost entirely dependent on class as well.

> Moreover, I don't need only browsing capabilities, but also the user
> should be able to see data, let's say a foaf:Person stored in my triple
> store, in a editing form and change it, the same way we currently do
> with non semantic web applications.

Editing is on our to do list.

> Finally, I would like that the user has no need to download/install
> anything locally, just point the browser to some URL, where my
> application would answer.
> Is this possible with Longwell? May it be changed/extended to suite this
> needs? May I use it as a "programmer-oriented Frensnel implementation",
> in the sense explained above? Does anyone know tools that may help me?

I'm not clear on your direction in regards to being less dependent on
class type. What would you rely on? I'll confess immediately that I
haven't looked at your ontology. If not having that reliance is going
to be essential to your application, Longwell itself may not be the best
engine for your needs. It's directed at the more general level of RDF
graph browsing, not necessarily at specific application domains. I
don't know how easy it would be to adapt.

If it's not a problem, Semantic Bank may be a good place for you to
start. SemBank has add/delete capabilities built in already. It seems
to fit much of what you're looking for, as long as you're willing to
make the changes you need yourself. Velocity templates and the code are
there for you to make adjustments.

Fresnel is actually a separate implementation geared towards use in a
Sesame based application. There's an API (be careful, the javadoc is
not at all up to date) and a command line version to demonstrate usage.

Ryan Lee       
W3C Research Engineer    +1.617.253.5327
Received on Mon Feb 27 2006 - 22:14:21 EST

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