Why does my Backbone model hasChanged() always return false?

Question

Given the following snippet:

var m = new Backbone.Model({
    name: 'joshua'
});

m.set('name', 'something else');

If I now call m.hasChanged() or m.hasChanged('name') I get false. Why? My understanding is that both of these should return true.

m.changedAttributes() also returns false.

Here is a fiddle that illustrates what I'm doing, and expecting: http://jsfiddle.net/9cvVv/88/

EDIT: It seems that unless you pass { silent: true; } to the set() method then it will fire the change event on your model which clears out the changedAttributes(), etc. Essentially these properties only track changes since the last time the change event was triggered.

I read that in the documentation but didn't really understand it at first.

This doesn't seem very useful to me. I would appreciate any explanation of why this works the way it does and the best way to achieve the result I want. (Passing around {silent: true; } and giving up usage of the change event seems like a waste.)

Answer 1

Unless you pass { silent: true; } to the set() method then it will fire the change event on your model which clears out the changedAttributes(), etc. Essentially these properties only track changes since the last time the change event was triggered.

So the answer is to call this instead:

m.set('name', 'something else', {silent: true})