GWT Generator, Part 1: What is GWT Generator?

I have recently wrote my first GWT generator, and I must say, it was a very elusive task to complete. Many times I thought I have finally grasped it, and yet came another problem. I wasn't able to find any simple example in Internet that worked both in development mode, and then compiled without any problem.

Finally, when I was finished, it was very easy in retrospect. But lack of detailed documentations made the task difficult, or I would rather say elusive. It was so frustrating, that I have decided to write my first ever blog entry :).

I have divided the topic of GWT generator in three posts. This is the first one regarding what is GWT generator. Second one here shows a simple GWT generator example. And a third one here provides simple ways how you can debug your GWT generator.

So what is GWT generator: GWT generators are a way to replace some GWT client codes with some generated code at the compile time (through deferred binding).

Examples of where you might use GWT generators could be:

• Use the full power of Java Runtime Environment, instead of the emulated JRE GWT provides (which is limited in many aspects). This can be useful when your required features are missing in GWT JRE (like File IO).
• Since you have the power of standard JRE, you can use generator as a wrapper towards third party Java library that does not work inside GWT emulated JRE. For example, you can read SVN information of your project, and make a build ID. Or you can use a template engine to emit code from some template.

Follow this post if you are interested in a very simple GWT generator example.