EmberJS: Accessing child controller functionality in parent - ember.js

Question

This may be more of a structure question but the heading is my current issue.
I have the following basic app:
var App = Ember.Application.create();
App.ApplicationAdapter = DS.FixtureAdapter.extend();
App.Router.map(function () {
this.resource('numbers', {
path: '/'
});
this.resource('users');
});
App.UsersRoute = Ember.Route.extend({
model: function (params) {
return this.store.findAll('user');
}
});
App.NumbersRoute = Ember.Route.extend({
model: function (params) {
return this.store.findAll('number');
}
});
App.User = DS.Model.extend({
name: DS.attr('string'),
numbers: DS.hasMany('number', {
async: true
})
});
App.Number = DS.Model.extend({
value: DS.attr('number'),
user: DS.belongsTo('user')
});
App.NumbersController = Ember.ArrayController.extend({
total: function () {
var total = 0;
this.forEach(function (number) {
total += parseFloat(number.get('value'));
});
return total;
}.property()
});
App.User.FIXTURES = [{
id: 1,
name: 'Bob',
numbers: [100, 101]
}, {
id: 2,
name: 'Fred',
numbers: [102]
}];
App.Number.FIXTURES = [{
id: 100,
value: 25,
user: 1
}, {
id: 101,
value: 15,
user: 1
}, {
id: 102,
value: 60,
user: 2
}];
Working example with templates is here: http://jsfiddle.net/sweetrollAU/9DuR3/
The example shows a relationship between users and numbers. The first page is a list of all numbers in the app, their related user and a total of all numbers. The Users link shows the same content but each user should show its own subtotal for the numbers it has.
My question is basically, how can I access the NumbersController method 'total' in my UsersController? Should I be accessing this method or do I have the structure incorrect?
Thanks

Answer 1

In your case they are similar logic, but they ultimately come from different data sources. You can still create a Mixin that can help you share the code amongst different Ember objects.
App.AddNumberMixin = Em.Mixin.create({
sumNumbers: function(arr){
var total = 0;
arr.forEach(function (number) {
total += parseFloat(number.get('value'));
});
return total;
}
});
App.UserController = Ember.ObjectController.extend(App.AddNumberMixin, {
total: function () {
return this.sumNumbers(this.get('numbers'));
}.property('numbers.#each.value')
});
App.NumbersController = Ember.ArrayController.extend(App.AddNumberMixin, {
total: function () {
return this.sumNumbers(this);
}.property('#each.value')
});
http://jsfiddle.net/9DuR3/2/

Answer 2

#kingpin2k's answer seems sufficient, but here's another way to do it:
http://jsfiddle.net/9DuR3/3/
What happens here is that the numbers are rendered again, for each users, but this time with a different template. Namely the one between the {{render}} tags. The NumbersController is provided with the user.numbers collection, instead of the complete numbers collection.
Also it's important to specify on which properties the total function dependent is (.property('#each.value')).