A Preview of GWT 2.0

Google Web Toolkit (GWT) is an open source set of tools that allows web developers to create and maintain complex JavaScript front-end applications in Java. It is licensed under the Apache License version 2.0. The GWT’s mission statement focuses on radically improving the web experience for users, by enabling developers to use existing Java tools to build no-compromise AJAX for any modern browser.
Google is set to launch GWT 2.0 later this year. The progress of GWT has been slow but steady over the years. Let us explore the road traveled so far and what lies ahead
The miles travelled…
Google promises much more with the GWT2.0 version scheduled to release later this year. Its various versions have been made available in the following sequence, with 2.0 following…
GWT 1.0 May 17, 2006
GWT 1.1 August 11, 2006
GWT 1.2 November 16, 2006
GWT 1.3 February 5, 2007
GWT 1.4 August 28, 2007
GWT 1.5 August 27, 2008
GWT 1.6 April 07, 2009
GWT 1.7 July 13, 2009
The launch…
And in comes the GWT 2.0 scheduled to be launched later this year. There is a lot on offer for this new version as Google promises to improvise it. GWT 2.0 contains huge improvements, including dynamic script loading, a new catalog of compiler optimizations, and a new approach to hosted mode debugging that uses the native browser.
The hosted mode is a key to productive development and it helps in debugging, editing etc. The problem is that the hosted mode browser is too special e.g. on Linux, hosted browser is an ancient Mozilla, hard to simulate interactions with other technologies (e.g. Flash) and it is impossible to debug browsers on non-dev OSes (e.g. IE from Mac). The GWT solves these problems by making hosted mode work with most native browser and make it work across the network.
Another huge advantage will be the compiler enhancements that come with the new kit. This new version promises much faster compilations, size, speed and obscurity benefits.
A new feature is the developer-guided code splitting. Often the compiled script size can be a problem because it holds all the code and can grow very big. Hence, the initial download can be too slow; UI hangs during script parsing etc. GWT 2.0 provides a solution, in code splitting by using- runasync. It is intentionally developer-guided and async. It intentionally forces you to think about failure paths. The split point doesn’t necessarily split. The compiler decides how to cluster code and it is guaranteed to be correct, ordering-wise.
Another new feature is the ClientBundle which generalizes ImageBundle to arbitrary resource types. With ClientBundle not only images are bundled together, all the resources (like CSS) are getting bundled. The obvious advantage is that only one file has to be downloaded, hence, less HTTP requests and faster download. Additionally, resources like CSS are getting optimized for size. At the Google I/O presentations it was also mentioned that in later versions ClientBundle probably also handles binary resources using Base64.
In GWT 2.0 there is the possibility to create a RPC blacklists which tell the RPC subsystem to skip types that you know aren’t ever sent across the wire and so doesn’t get compiled and stuffed into the code base. GWT 2.0 also promises a faster, easier and more predictable layout (at last). The standards mode provides new leverage including constraint-based layout that actually does what you say and also you’ll never have to hook the window resize event again. There is an updated set of Panels in GWT 2.0.
Version 2.0 will bring GWT a huge step forward and boost performance for developers and clients. It is not official, but 2.0 maybe also brings a new XML based markup language to define the layout. My guess is that the syntax will be close to HTML. Let’s hope that the new version attracts more GWT developers and which hopefully results in more widget libraries and extensions.

For more details please visit http://www.hemju.com/2009/07/24/a-preview-of-gwt-2-0/