You're currently binding the totalBoth
variable to the class definition and not an instance of a class, which just wont work. What you want to do is observe for changes in any of the instances.
Check out this updated JSBin: http://jsbin.com/cuqitufo/6/edit
The trick is to use the @each property for aggregate data.
So you no longer need the binding, you just observe the calculatedTotal of each instance: App.TypeNumbers.@each.calculatedTotal
:
totalBoth : function(){
var total = 0;
App.TypeNumbers.forEach(function(item){
console.log( item.get('calculatedTotal') );
total += item.get('calculatedTotal');
});
return total;
}.property( 'App.TypeNumbers.@each.calculatedTotal' ),