Computed value in DS.Model returns Promise instead of Value

[azhang]

more specific details here: http://stackoverflow.com/questions/18835533/ember-data-model-computed-value-return-value-instead-of-promise

I'm trying to show a computed value in my template, but since the computed value uses an async linked model, it returns a promise. Is there any way to get or set the value when the promise is fulfilled?

[wycats]

You can try something like this:

App.Survey = DS.Model.extend({
  title: DS.attr(),
  owner: DS.belongsTo('user'),
  questions: DS.hasMany({ async:true }),

  totalResponses: Ember.arrayComputed('questions', {
    initialValue: 0,
    addedItem: function(accum, item) {
      accum += item.get('totalResponses');
    },
    removedItem: function(accum, item) {
      accum -= item.get('totalResponses');
    }
  })
});

When questions resolves, the addedItem callback in totalResponses will be called once for every item in the resolved array.

[azhang]

thanks! I'll try that.