MVC Frameworks for GWT: A Brief Survey

One of the more difficult aspects of using the Google Web Toolkit for enterprise development is its lack of a framework.  This is by design: GWT is a toolkit, not a framework.  It doesn’t tie you into a single approach or methodology, it lets you use any you like.

That freedom is both a blessing and a curse.  You don’t have to learn a new model or way of doing things… because GWT doesn’t give you one.  This is especially true of the Model-View-Controller (MVC) pattern, which I was introduced to when learning AWT and Swing programming for Java.  There are a number of third party projects which step up to provide an MVC framework for GWT; some have been around a while, others are newcomers to the scene.

Gwittir appears to be the most mature; it also has the most confusing name.  (I originally thought it was a GWT interface to Twitter.  It isn’t.)  The Gwittir team provides ample documentation and even a “Gwittir Way.”  Gwittir is heavier than the other MVC projects, but I suspect that if you follow the Gwitter Way you’ll be saved the trouble of implementing a lot of common components yourself.

GWTruts draws its inspiration from Struts, offering dependancy injection and providing MVC configured via XML configuration files.  If you find XML to be a comfortable way to define a user interface, you should look into this package.

The package which had the greatest influence on our internal GWT MVC efforts was the GXT MVC package.  It has the least documentation — although there is this javalobby article — and appears to exist only to support the GXT widget examples at this point.  We’re using the GXT widget library and I admit that I discovered the GXT MVC package purely by accident — but it provided a good, easily understandable lightweight MVC approach.  You need to fill in much of the code if you use this as your framework; it’s nowhere near as fully featured as the other projects listed here.

The GWT-MVC project is the lightest of the standalone MVC frameworks.  It’s a step above the GXT MVC package in terms of heaviness, but like that framework it requires you to fill in much of the implementation yourself.  There’s something to be said for this approach, as it doesn’t tie you to project-specific configuration and APIs so much as give you a leg up on developing your internal framework.

The Google Web Toolkit is a great contribution to the web development world, as it makes developing and deploying rich internet apps much easier for Java enterprise shops.  Thanks to contributions from a number a projects we’re seeing progress in the MVC framework space, and there are a number of interesting options to choose from out there.

Update: I just became aware of mvc4g, another Struts-inspired, xml-driven MVC framework.  Did I mention there was a lot of activity in this area?

Update: Changed the GWTruts section so it no longer gives the impression it’s only for small apps; per the comments I’ve recieved it sounds like it scales quite well to large apps as well.