gistfile1.txt

MyApp.MyObject = SC.Object.extend({

    property: value;

    computedProperty: function(){
         return this.get('property') === "foo";
    }.property('property'),

    setProperty: function(value){
       this.set('property',value);
    }

});

MyApp.someObject = SC.Object.create({

      object: MyApp.MyObject.create(),

      iShouldFire: function(){
           console.log('I should fire');
      }.observes('.object.computedProperty')

});