Question

Sample Code:

var Day = Ember.Object.extend({
  date:null,
  activities:null, // is set to an Em.ArrayProxy in instantiation
  historicalSection:function(){
    return this.get('activities').filterProperty('inHistoricalSection', true);
  }.property('activities').cacheable()
});

When ‘activities’ is set to an ArrayProxy, ‘historicalSection’ computed property gets computed. However, when the ArrayProxy at ‘activities’ gets updated(i.e. its length changes), the ‘historicalSection’ property doesn’t update.

Any ideas why?

Answer 1

When you bind the computed property on activites, it means that it will be updated when you set a new value for activities, so at init time, and only when calling set('activities', newArrayProxy).

You can use activities.@each or activities.length as the bound property to observe the length changes