Computed property being observed doesn't fire if changed twice in a row

Question

I have an Ember.Object that I'm updating with a property like below, but if I change primaryDemo twice in a row, it doesn't fire, yet if I change primaryDemo, then Rate, it does change. I'm puzzled as to why this is and how I can fix it.

dependantChanged: function() {
    console.log('Firing change');
    this.get('_update')(this);
}.observes('primaryDemo', 'Rate', 'Totals'),

UPDATE: So the first answer and fiddle got me thinking as to what the problem was, and it's due to changing a property on an object and not the object itself. I think ember does a hash check to see if there is a difference. In my case I'm already using underscorejs, so I just change the property, then use _.clone(demo) before doing the set. I'd rather not do that, so will wait to see if there is a more elegant solution before closing this.

Answer 1

You don't need to set primaryDemo again. In the example that does nothing. You need to force tell Ember to notify your observer. See this fiddle...

var demo = { Imps: 1, Demo: { Id: 2 } }

var obj = Ember.Object.create({
    dependantChanged: function() {
        console.log('Firing change');
    }.observes('primaryDemo', 'Rate', 'Totals'),
});

obj.set('primaryDemo', demo);
demo.Imps = 2;
obj.set('primaryDemo', demo);

// Notify observers on obj#primaryDemo
Ember.notifyObservers(obj, 'primaryDemo');

​

Answer 2

Can you give more details? I created a simple JSFiddle http://jsfiddle.net/JjbXb/ from your description but changing the same property in a row, as you say, works.

Are you sure the value of primaryDemo is different in your 2 consecutive calls?