Thinlet Titan Interview With Michael Nascimento Santos

Hello,

 Welcome back to the Thinlet Titan Interview series.
Today let's welcome Thinlet committer and Genesis
founder Michael Nascimento Santos.


Q: Can you tell us a little bit about yourself?

Michael Nascimento Santos: I've been programming since
I was 11 years old. My interest on Java began when a
edition of a famous magazine in Brazil came out with
an article about a new "hot" programming language. I
had tried OOP before using Clipper and lots of
compiler tricks (#xcommand, #xtranslate etc.) and I
was looking for a more powerful and expressive OO
language that wasn't as low as C++. Visual Basic
wasn't good enough, but Delphi actually appealed to me
at that time. However, when I found Java, I got crazy
about it almost immediately. It was very powerful but
yet significantly simpler when compared to C++. It's
been 5 years I've been coding almost exclusively in
Java and I don't regret it.

Nowadays, I help to run SouJava, one of the world
largest JUGs, manage the JSR community @ java.net,
serve as expert at JSR 207 (PD4J) and 250 (Common
Annotations), and help to develop Thinlet as a
committer and AspectWerkz as a contributor. I've also
spoken at many events, such as JavaOne, JustJava,
BrasilOne, Javali (FISL), Abaporu, COMDEX Brazil and
others. I'm very proud to work at Summa Technologies
do Brasil, which is recognized by the community as
being the leading company for Java development,
mentoring and consulting in the country and also has
an office at Pittsburgh.

We've just released a Thinlet-based open-source
framework (that does much more than UI, by the way)
called genesis, hosted on java.net at
http://genesis.dev.java.net


Q: How did you stumble onto Thinlet? Have you tried
 out any alternative XML UI toolkits for Java before
 settling on Thinlet?

Michael: One of our customers asked us which
technology they should use to migrate their
over-10-year-old client-server applications - which is
a very common scenario in Brazil. They needed
something that produced very lightweight (some of
their machines have 16MB of RAM), responsive and
easy-to-develop UIs. So we first asked everyone at
Summa for alternatives to Swing (which obviously
didn't meet the first and the third requirements) and
Eduardo Ito, our "encyclopedia" guy, come up with
around 50 frameworks that could be useful, including
Thinlet, SwiXML, SwingML, wingS, Zaval, Millstone,
Luxor, Naked Objects and others. After some testing,
we were sure Thinlet was the way to go. In around 2h I
was able to code the entire UI logic for a somewhat
complicated logic. Designing the UI itself just took a
few minutes, so at that moment I was sure Thinlet was
just what they've been looking for. The funny thing is
that although we did this research almost one year
ago, they didn't start using Thinlet until very
recently, but we've been using it since then in many
projects. It's just great.


Q: What's the hook? Why would anyone use Thinlet over
say plain old Java Swing coding?

Michael: For the same reasons we've been using it:
it's easy to teach, easy to use, fast to develop with,
produce responsive UIs without too much thinking and
has a very intuitive API. Swing is painful and, it's
very hard not to produce slow, unresponsive UIs with
it. It takes ages for someone to master it. You don't
want your UI programmers to be senior programmers
unless you're doing some sort of very specific
software in which you need high control and
extensibility in order to do your work.


Q: Can you highlight some of your apps built using
Thinlet?

Michael: Before Javali's effort to develop a free,
open-source JVM, I was asked to take a look at the
different open-source VMs already available and how 
they did compare to each other and especially to Sun's
implementation. I developed client-server application
consisting of a remote test server for each VM
configuration and a performance meter workbench that
would allow one to register remote VMs, select which
tests to run, how many iteractions shouldn't be
considered (warm-up iteractions), how much time to
pause between iteractions, whether or not to invoke
the gc between them, how many runs each iteraction
should have, and much more. Then, you could start 
the remote tests and the workbench application would
collect statistics about each run of each test in each
VM, allowing you to analyze them using many different
perspectives, such as test results per VM, VM
performance per test and so on. This was my first
"serious" Thinlet application and I learned a
lot about how to develop applications using it. The
first need I noticed was to write strongly typed
setters/getters for properties, methods to create
rows and items based on Collections and things like
that.

One application we are particularly proud of was one
developed for a customer that needed to get rid of
Dataflex in their core business, mission-critical
application. It was a sales system with complex
business rules and many UI iteractions that could
cause the whole screen to be repopulated in order to
always display consistent data. It was quite a
challenge since one of the requirement was that our
customer's existent 
team could develop it with us and actually understand
the technology involved, at least well enough so they
could maintain it by themselves. Before 
starting this project we were looking for a way to
solve exactly this problem and we got our solution
ready in time. We've developed a framework that solves

the client-side problem by extending Thinlet and
integrating it with commons-beanutils and
commons-validator. Now, it's far more mature, handles
many other situations and is available as open source
software at http://genesis.dev.java.net

I've also recently helped one of our customers to
define a platform for PDA development using Thinlet
with genesis. It was quite interesting to see Thinlet
working seamlessly on the device. :-)

Q: Can you tell us some challenges you faced building
your apps using Thinlet?

Michael: We've found out Thinlet dialogs don't work
very well for some users, so we had to replace their
use with java.awt.Dialogs. A limitation that got in
your way in the beginning was the fact you can't edit
a
cell in a table directly. We've got around this by
opening an auxiliary window when the user double-click
the row. There were some critical bugs in spinbox and
table that took me some time to fix.

Q: How did you get started on AspectWerkz?

Michael: A friend of mine, Carlos Villela, told me
about it once and I checked out their site
immediately. It seemed very attractive to me since
that first contact because it didn't require an odd
syntax, new keywords or IDE plugins. Then, when I
needed to do something serious with AOP (transparent
remoting, the first genesis feature) I tried it and
got it working really quickly. At that time, AW 0.9
was in beta and its license wouldn't allow me to use
it in our project that would start in two weeks. I
sent an email to AW user's list about it and Jonas
Boner and Alex were very responsive, doing a release
and changing the license really quickly. When I
noticed they were so responsive and that AW was so
easy to use and powerful, I was sure it was the right
AOP framework for us.

Q: Can you tell us what aspects and cross-cutting
concerns you use in your Thinlet app(s) and how AOP
 fits into the Thinlet world?

Michael: Well, most things at genesis are implemented
with aspects: transparent remoting, transactional
support, dynamic searches, enabling/disabling fields
declaratively, showing/hiding widgets, calling
validation before executing a UI action and much more.
AOP is great when you use Thinlet on desktops and Java
1.3/1.4. Its usage has made our code very clean,
maintainable and testable. It's a perfect couple :-)

Q: What's your take on adding styling support to
 Thinlet? Have you tried out Eugene Klein's Skinlet
addon?

Michael: Skinlet is great. I hope to be working really
heavily on Thinlet in the first quarter of 2005. This
one of the things I expect to discuss with other
commiters.

Q: Do you have a favorite scripting language for the
 Java runtime? Do you want to see scripting pushed
more
 in Thinlet or do you want to keep the code Java only?
 Have you tried out Norbert Barbosa's Scriptable
 Thinlet addon?

Michael: Scripting certainly has its value if used
propertly. Scriptable Thinlet will definitely help you
being productive if you are working on
small-to-medium-sized projects. However, as your
project grows, it can turn into a nightmare. I like
the idea of using script fragments to declare
conditions, as we do in genesis. I especially like
Groovy and JavaScript, as well as JXPath, which is not
a scripting language exactly, but can be used as one.

Q: What's your take on creating an OO wrapper for
Thinlet?

Michael: I think I don't really like the idea. If you
find Thinlet model too raw, you better move to a UI
component model where your POJOs with presentation
logic are not even aware of which API is being used
for
displaying them. That's the approach implemented by
genesis. genesis forms are totally independent from
Thinlet.

Q: What do you think is still missing in Thinlet?

Michael: Easy support for custom components and more
hooks for built-in widgets, such as key listeners,
input validators, etc. I hope I can work on that soon
in a way that is still Java 1.1.8 and there is no
overhead if you don't use these features.

Q: As a Thinlet committer do you have any suggestions
 on how to improve the Thinlet development process?

Michael: Tools are already available, but are not
being used properly - some are actually not being used
at all. Bugzilla/issuezilla is the most critical of
them, for example.

Q: What are your future plans for Thinlet?

Michael: I hope I can make Thinlet much more
extensible and flexible. If Thinlet has this
characteristics, it will become a killer UI framework.

Thanks Michael Nascimento Santos.


Links:
* Genesis - http://genesis.dev.java.net
* Thinlet, Skinlet, Scriptable Thinlet & Co -
http://thinletplus.com
* AspectWerkz - http://aspectwerkz.codehaus.org


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