Tapestry 5 and Groovy

I was curious just how well T5 and Groovy would work together, so I took an existing application, enabled Groovy for it (using the Eclipse plugin) and added a Groove page to my existing application:

package org.example.hilo.pages;

class Holder
{
  String firstName;
  String lastName;
  int age;
}

class Groove {

 def message()
 {
   "Get your Groove on, Baby!"
 }
 
 def onAction()
 {
  println "onAction invoked"
 }
 
 def items()
 {
   [ new Holder(firstName: "Howard", lastName:"Lewis Ship", age:40), new Holder(firstName: "Scott", lastName: "Simon", age:42) ]
 }
}

Guess what? It just worked, no problems. I generated a Grid with the two Holder items, my onAction() method is invocable, and I can retrieve the message. It is just bytecode under the covers.

Alas, without some kind of annotation support, there's no way to mark a field as persistent, so there's tremendous limits on what can be accomplished right now. I've heard rumors that some kind of JDK annotation support is forthcoming; failing that, I've thought about an additional file, read at runtime, that would provide class, method and field annotations. But I'd rather someone else does it.

In addition, Tapestry is reading the compiled .class file; I haven't even thought about trying to get things to work from uncompiled .groovy files and I can imagine there may be some class loader headaches there.

Still, for five minutes effort, it was nice. And I really think I could come to really like the streamlined, sensible syntax ... and for god's sake, first class closures!