The problem is that you’re trying to define an observer in Ember.Object.create
when it’s normally done while defining a class with Ember.Object.extend
. Either you should define a class like this:
var TmpDocument = Ember.Object.extend({
and then instantiate your tmpDocument
instance from it, or you need to add the observer to the document after it’s created like I did in this working modification of your JS Bin:
tmpDocument.addObserver('Category', function() {
console.log('Category changed to: ' + this.Category);
});