EmberJS Inheritance Conundrum - ember.js

Question

Consider this situation. I have a common logic which I want to reuse across Ember.ArrayController and Ember.ObjectController instances.
Both Ember.ArrayController and Ember.ObjectController are derived from a basic Ember.Object so I am trying something like:
AbstractController = Ember.Object.extend({
// some methods with common logic
});
AbstractArrayController = AbstractController.extend({});
AbstractObjectController = AbstractController.extend({});
The problem is I also need AbstractArrayController and AbstractObjectController to extend from their parents (Ember.ArrayController and Ember.ObjectController).
How would I achieve this sort of inheritance?
I am looking at reopen and reopenClass methods right now, maybe they could be useful: http://emberjs.com/api/classes/Ember.Object.html#method_reopen
I tried just doing something like:
Ember.Object.reopenClass({
foo: function () {
return "foo";
}.property("foo")
});
But that doesn't seem to work.
Another way to put the problem:
App.HelloController = Ember.ObjectController.extend({
foo: function () {
return "foo";
}.property("foo")
});
App.WorldController = Ember.ObjectController.extend({
foo: function () {
return "foo";
}.property("foo")
});
How to abstract the foo computed property?

Answer 1

reopenClass adds methods on the class object, not the instance objects. When you do:
Ember.Object.reopenClass({
foo: function () {
return "foo";
}.property("foo")
});
You are creating Ember.Object.foo().
You need to use reopen if you want to methods at an instance level, for example Ember.Object.create().foo().
To answer you question, the best way to abstract a function that many types of objects can use is with a mixin. To create a mixin you use.
var mixin = Ember.Mixin.create({
foo: function() {
return 'foo';
}
});
And to have your objects take advantage of that mixin you can use.
var MyController = Ember.ObjectController.extend(mixin, {
// ...
});
More about mixins: http://codingvalue.com/blog/emberjs-mixins/ and http://emberjs.com/api/classes/Ember.Mixin.html