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GWT Designer now available for free!

By Olivier Gérardin

In case you missed it, Google announced last week that the tools from the rcently acquired company Instantiations were now available for free!

This is a great news because it includes GWT Designer, the famous (and only so far) graphical designer for GWT… It’s the perfect complement to the Google plugin for Eclipse.

Google Web Toolkit Blog: Google Relaunches Instantiations Developer Tools – Now Available for Free.



Slides from my GWT2 presentation at YaJUG

By Olivier Gérardin



Slides from my presentation at

By Olivier Gérardin



Smart GWT 2.1 has just been released.

By Olivier Gérardin

If you don’t know yet, SmartGWT is a cool GWT tookit made by Sanjiv Jivan (the guy who wrote GWT-ext). It is primarily intended to build SmartClient frontends, but it is also available standalone under LGPL license. SmartGWT is fast becoming a strong alternative to GWT-ext (stuck because of license issues) and Ext-GWT (very buggy and full of bad design choices).

SmartGWT 2.1 is out with lots of novelties.

SmartGWT on Google Code



Google Web Toolkit Blog: GWT 2.0.2 is now available

By Olivier Gérardin

Bugfix release…

Read blog entry




GWT and JavaScript Date hell

By Olivier Gérardin

You’d think that in 2010, date processing is something that is easily done in Java (and hence GWT), in a consistent cross-platform way. And you’d be wrong.

When I’m talking date processing, I mean simple calendar date (not time) operations, like: get today’s date, add a number of days, compute the number of days between two dates, etc. The original sin, so to speak, is that Java doesn’t have a class to represent a day; Java’s Date class is actually more like a timestamp: it encapsulates a moment in time (with a millisecond precision) stored as the number of milliseconds to/from the moment called “epoch”, which is arbitrarily fixed at January 1, 1970, 00:00:00 GMT.

The methods related to date components (day of month, month, year, etc.) have all been deprecated since the apparition of the Calendar class (JDK 1.1). The trouble is, Calendar isn’t available in GWT’s JRE emulation library. So what do most programmers do? They use the deprecated methods of class Date. For example to create a Date that corresponds to a given day, they would use new Date(y, m, d). Well it’s deprecated, but it works, right?

Wrong. When instantiating a Date object using these deprecated methods, each JavaScript implementation tries to do its best to guess the correct timestamp, based on things such as the current time zone and whether Daylight Savings Time was effective at that time, and of course these rules vary by OS, JavaScript implementation and depend on the client’s regional settings. I’m not going into details now, but the bottom line is: you can’t expect to get a consistent behaviour.

Actually, if you might not notice this problem if all you do is manipulate local dates that were created on the client-side; the problem really becomes a nightmare when you mix locally instanciated dates with serialized dates from the server.

We’ve spent an incredible amount of energy and time to work around this issue, which is made worse by GXT’s DateWrapper and DateTextField. The awkward but kind-of working solution that we use now is to subtract Date.getTimezoneOffset() from Date.getTime() in order to “cancel out” the client’s time zone and DST. Not pretty.

If I had to do my current project again, I would definitely stay away from the Date type on the client side. As primitive as it may sound, if I have to manipulate dates without a time part, I would stick to using a (day, month, year) triplet and do as little date calculations on the client-side as possible.

You’ve been warned!



GWT sighting in Palm’s webOS Mojo SDK

By Olivier Gérardin

While exploring the code samples that come with Palm’s SDK for webOS (named Mojo), I was pleasantly surprised to see that one of the samples (MojoMsgSample) uses GWT and the Google App Engine for the “cloud” part of the sample! It’s a basic publish/subscribe app, but still it’s nice to find oneself in known territory…

BTW, has anyone attempted to wrap the Mojo SDK in GWT? I’d be thrilled to be able to write webOS apps in GWT :)



It’s official: GWT 2.0.0 (with SpeedTracer)

By Olivier Gérardin

Logo GWTFinally, as anticipated Google set the “release” tag on GWT 2.0 and announced it at its Campfire One event yesterday. In addition to the well-known major new features (development mode, Code splitting, UiBinder, ResourceBundle), Google comes with a new tool named Speedtracer to measure the performance of Ajax applications inside the browser. SpeedTracer is only available for Chrome at the moment, unfortunately only on platforms where extensions are supported, which means not on Mac currently (actually it does work on Macs, see comments to this post)

The online docs have been updated and are still IMHO a model of how online documentation for a project should be done: clear, concise, well structured, complete yet progressive, with examples… it’s almost fun to read. I wish every project had docs like this.

Download GWT, SpeedTracer or the Eclipse plugin



GWT 2.0 RC2 available

By Olivier Gérardin

Logo GWTThe release is coming closer… Christmas gift anyone?

GWT 2.0 RC2 is available from this link. The Google plugin for Eclipse has been updated as well to 1.2 RC2

Caution Windows users who installed the IE plugin, you’ll have to uninstall it and install a new version (details there).



The book is out… Le livre est sorti…

By Olivier Gérardin

The same day as GWT 2.0 RC1, that has to be a good sign…

(cliquez sur le livre pour feuilleter une sélection de pages)