Creating a custom class which can return a custom event

[Cortana]

Just as it says on the tin. I want to create a class which will do its work, and when it's done, generate an event back to my movie.

I want to use my custom class like this :

var test:Main = new Main()
test.onDone = function() {
// blah blah
}

Is there any sample classes which do this?

Im tearing my hair out over this!

[senocular]

All you need to do is define onDone as a Function variable in Main

...
public var onDone:Function;
...

and then when it does the things you need, in whatever Main method that does those things (note this cannot be the constructor if a synchronous process since it will complete before you have a chance to define onDone), call it:

 if (onDone) onDone();

In ActionScript 3, however, its more common to use EventDispatcher and addEventListwner/dispatchEvent