Myujth

With the future of JS on Java unclear (JS/Nashorn deprecated on Java 11), I've been looking into options completely outside of JS, Groovy being a major one given its popularity and similarity to Java.

I currently use JS/Nasahorn to handle a lot of actions for a game server, and while a lot of it I can see can be converted to Groovy, I do have one concern that I'm having trouble figuring out if possible or not.

So with my game server, there are new clickable map objects and npcs being added all the time (with a total of each being in the tens of thousands). To deal with the click actions of these, I have JS classes to handle them.

To add a new object or npc action, I have groups of JS files that split the ids up so that it isn't one giant file. Specifically, I use the JS prototype to be able to add these actions in without being the same file, and just load all the JS files at runtime.

ObjectOption.prototype.object_0 = function(player, object) 

And then I'm able to execute the functions from the actual JS class itself via

ObjectOption.prototype["object_" + object.getID()](player, object);

or

this["object_" + object.getID()](player, object);

My question is, can any such setup be done with Groovy, or is this outside the scope of how Groovy works?

Groovy supports metaprogramming that allows you e.g. adding new methods to existing classes at the runtime. Consider following example:

class Person 
 void greetings(String name) 
 println "Greetings, $name!"
 


Person.metaClass.hello = String name -> println "Hello, $name!" 

def john = new Person()
john.greetings("Paul")
john.hello("Mary")

Output:

Greetings, Paul!
Hello, Mary!

In this example, we have a simple Person class with a single method greetings(). We are able to add a new method hello() by accessing Person.metaClass object and adding method hello as a closure that accepts a single parameter name of type String.

Check the Groovy's documentation on metaprogramming, you will find many examples there.