Ember 0.9.8.1 Template

HTML

<script src="https://github.com/downloads/emberjs/ember.js/ember-0.9.8.1.js"></script>
<script type="text/x-handlebars">
    
</script>

JavaScript

App = Ember.Application.create();

App.parentsController = Em.ArrayController.create({
    content: [],
    selected: null
});

App.sonsController = Em.ArrayController.create({
    // the value of content depends on the id of
    // the selected item in the parentsController
    parentControllerBinding: 'App.parentsController',
    content: [], 
    
    updateContent: function() {
        var selected = this.getPath('parentController.selected');
        var newContent = Ember.A();
        newContent.pushObject(selected);
        this.set('content', newContent);
    }.observes('parentController.selected')
});

console.log('parentsControllerSelected:' + App.parentsController.get('selected'));
console.log('sonsControllerContent:' + App.sonsController.get('content'));

App.get('parentsController').set('selected', Ember.Object.create({foo: "bar"}));

Ember.run.end(); // force the end of the run loop

console.log('parentsControllerSelected:' + App.parentsController.get('selected'));
console.log('sonsControllerContent:' + App.sonsController.get('content'));