Comments on: GWT: generating the factory

By: Lars

Lars — Fri, 30 Jul 2010 04:20:40 +0000

Thanks a lot for the write-up – just what I needed. It’s a nice and clear intro to generators.

By: olivier

olivier — Wed, 04 Nov 2009 08:37:28 +0000

That would be nice, but unfortunately it doesn’t work: eval chokes on the “new” syntax.
I believe you can only use this construct when you have a literal class name, not inside an eval string.

By: Dave Finch

Dave Finch — Wed, 04 Nov 2009 07:50:42 +0000

Thanks for your help.

By: David

David — Tue, 03 Nov 2009 20:21:49 +0000

Or maybe a better class/method name combination is GWTInstanciator for the class and newInstance for the method.

By: David

David — Tue, 03 Nov 2009 20:20:37 +0000

I have almost no experience in GWT but isn’t the simplest solution to your “generator problem” to have a single class ControllerResolver with a static resolve(Class clazz) method as follows:

public static native Object resolve(Class c) /*-{
return eval(“@”+c.@java.lang.Class::getName()+”::new()()”);
}-*/;

or something along those lines (have not tested for correctness, just trying to give the idea)

By: olivier

olivier — Tue, 03 Nov 2009 15:12:20 +0000

Sure.. If you set the GWT compiler's log level to DEBUG (warning: it generates an insane amount of messages!), somewhere in the junk you'll see this sequence:

    Invoking 
             Generating substituted-target-class
                 (your own log messages...)

and after it's done:

             Generator returned class 'your-generated-class'
             Finished in 35 ms
          Assimilating generated source
             Generated source files...
                file:/path/to/generated/source.java

That's where you will find the generated source file.

By: Dave Finch

Dave Finch — Tue, 03 Nov 2009 13:26:00 +0000

Nice article.

One quick question that you may be able to help me with:

If the generated output does not compile then logs will point to a java file in your temp folder but if everything compiles OK but doesn’t do exactly what it should how (or where) can you see to generated coded?

Thanks,
Dave

By: Sakuraba

Sakuraba — Tue, 03 Nov 2009 08:59:22 +0000

Thank you so much for this blog post. I always wanted to know about Generators and thanks to your insightful introduction I finally understood what they are all about.

By: olivier

olivier — Mon, 02 Nov 2009 22:11:51 +0000

Mostly because I wanted to learn how to use GWT generators
I considered Gin but it seemed overkill for what I wanted to do.

By: Benju

Benju — Mon, 02 Nov 2009 17:53:38 +0000

Why not use Google Gin for this?

http://code.google.com/p/google-gin/