Ember setupController fires observes, how can i prevent that - ember.js

Question

My code looks something like this
App.ItemRoute = Em.Route.extend({
setupController: function(controller) {
var model = this.modelFor('item');
controller.setProperties({
name : model.get('name'),
title: model.get('title')
});
}
});
App.ItemController = Em.ObjectController.extend({
saveOnChange: function() {
console.log('saveOnChange');
}.observes('name', 'title'),
});
From my understanding because i am using setProperties the observe should only fire once , but it fire two times
also wrapping the setProperties with beginPropertyChanges & endPropertyChanges still fires twice
what i ultimately is for it to not fire at all, so what i ended up doing was changing the controller code to be like this
App.ItemController = Em.ObjectController.extend({
load: false,
saveOnChange: function() {
if(!this.get('load')) {
this.set('load', true);
return;
}
console.log('saveOnChange');
}.observes('name', 'title'),
});
this code would work if the change is only fired once, but it won't work if its fired multiple times (that's my case)

Answer 1

The setProperties function doesn't coalesce your observers (unfortunately there's no way to do that), it just groups them into one operation. The source might help you to better see what it does:
Ember.setProperties = function(self, hash) {
changeProperties(function() {
for(var prop in hash) {
if (hash.hasOwnProperty(prop)) { set(self, prop, hash[prop]); }
}
});
return self;
};
So, back to your problem. The best way that I can think of is to debounce your function.
App.ItemController = Em.ObjecController.extend({
load: false,
saveOnChange: function() {
Em.run(this, 'debouncedSave', 150);
}.observes('name', 'title'),
debouncedSave: function() {
if(!this.get('load')) {
this.set('load', true);
}
}
});
If you're not familiar with debouncing, you can read about it here. There are probably some other solutions involving direct manipulation of the properties, but I'm not sure if that's a road you want to go down.