GWT Community Updates

Community announcements

GWT-in-the-Air (and in Yahoo! BrowserPlus^TM): Thomas Broyer, one of our GWT contributors and a regular on the forum, has been working on the GWT-in-the-Air project over the last year. The project provides an Adobe AIR version of your GWT application, making it ready to run in the browser or on the desktop. Thomas has most recently added support for Yahoo! BrowserPlus^TM as well, which allows you to add desktop capabilities to your GWT app.

GChart 2.6 released: John Gunther recently announced the GChart 2.5 release, which adds a GWT canvas rendering option for better looking charts and graphs.GChart 2.6 was also published recently which fixes deprecated event listener calls and other bug fixes. Check out the live demo and examples if you're interested in using it for your own GWT application.

An early look at Spring4Gwt: Dustin Mallory has recently created a new project called spring4gwt, which, as you may have guessed, offers a way to integrate GWT with the Spring framework. The project is still in its early stages, but aims to offer both exported Spring services to the GWT client and DI that works specifically for Spring components.

GWT-cs - Springifying your GWT application code: We've seen integrating with Spring, but what if you wanted to develop your GWT client-side code in a Spring-like fashion? In comes the newly started GWT-cs project for just such a use case. With this library, you can develop your GWT client-side application structure using Spring-like bean configuration in an XML format.

Uploading with GWTUpload: While the FileUpload widget in GWT core provides one part of the key to uploading files in your GWT applications, the server-side component and it's interaction with the client-side form submission is often the part developers get stuck on. Using GWTUpload, you can get file uploads ready in just a few steps. You also get other nifty features like progress bars showing file upload progress (file size, bytes transferred).

New Articles on the GWT homepage

We've recently published new articles on the GWT homepage, including:

• Using GWT with Hibernate: A tutorial articles that explains step-by-step how to integrate GWT with Hibernate using one of various integration strategies, while discussing the pros and cons of each approach.
• Testing Methodologies Using Google Web Toolkit: An article describing how to design your GWT application test-first, using principles of Test-Driven Design and the Model-View-Presenter (Passive View) pattern.

These articles were created to address the many inquiries we've seen on integration and testing topics, so hopefully they will be helpful to you if you're at the point of making integration or design decisions in your GWT project. Also, many of these articles were written in collaboration with the GWT developer community, so if you have any articles or topics that you would like us to consider for publishing on the GWT homepage, feel free to get in touch with us.

Google Web Toolkit 1.7 Now Available

GWT 1.7 is a minor update that adds better support for Internet Explorer 8, Firefox 3.5, and Safari 4. Each of these new browser versions introduced at least one change that negatively impacted compiled GWT modules, so we recommend that you do update to GWT 1.7 and recompile your existing applications to ensure that they work well with the latest versions of browsers. No source code changes on your part should be required.

Normally, a minor update such as this would have been named 1.6.5 (the previous latest version of GWT was 1.6.4), but we did add the value "ie8" to the "user.agent" deferred binding property, which could impact projects using custom deferred binding rules that are sensitive to that property. Thus, we went with GWT 1.7 rather than GWT 1.6.5, to indicate that you may need to pay attention to that change. Details are in the release notes.

In every other respect, this is just a bugfix release, so in the vast majority of cases, the update-recompile process should be nearly effortless.

Download Google Web Toolkit 1.7

Introducing the Debug Panel for GWT

The primary intent of the Debug Panel for the Google Web Toolkit (GWT) is to provide the developer of a GWT application performance data about the application as well as tools to debug the client side application code. Web applications built with GWT run mainly in the client's environment, over which the developer has little control or access. The Debug Panel provides tools to the developer to help lift the shroud over the client environment to help diagnose problems, help tune and improve performance as well as assist with application testing.

As with any application, testing and quality assurance is important to a GWT application. Because a GWT application is user facing, performance testing is very important. However, measuring the performance of an application running in a browser is not easy. With all the moving parts of the client code - RPCs, DOM updates, etc. - and the fact that with GWT you are no longer writing JavaScript, it can be hard to locate bottlenecks. Automating the performance tests and getting accurate numbers on RPC response time is even harder. This is where the Debug Panel for GWT comes into the picture. It is an external library that can easily be added to any GWT Web application and will provide you with that performance data, an insight into what goes on behind the scenes and help you automate the whole thing, too.

Here is a sample screenshot of the Debug Panel in action:

Here, the Debug Panel shows us the statistics of an invocation of the EchoService as well as the startup times. It is clear from the example that RPC finished quickly. It shows that the slowest component was waiting for the server to respond at 121ms. While serializing the request and deserializing the response both took 19ms, updating the UI with the data returned from the server only took 2ms. These are the kinds of numbers you would want to see!

Here is another example screenshot of the Debug Panel:

This time, the application was run in Hosted Mode and there was an exception during the RPC. Once you compile your application to JavaScript, the stack trace will be a JavaScript stack trace of course. The exception panel in the Debug Panel is also an example of the extensibility of the Debug Panel. As a GWT application developer, you can add your own panels to the Debug Panel that are customized to your application. The Debug Panel provides you with a framework to display your application's debug data as well as a lightweight component to add to your main application, so it can communicate the relevant data to the Debug Panel, without affecting runtime performance much.

In fact, you can plug the Debug Panel into an existing application without changing the application's code. This also means that there is no change required in the compiled JavaScript. Therefore, you can serve your GWT web application both with the Debug Panel enabled, to internal IP's for example, or disabled for everybody else.

Check out an online example of the Debug Panel, check out the example's source to see how easy it is to use or check out the Google Code project for more information.

Pascal Muetschard, Software Engineering Team