Backbone.js: Collection's "change" event isn't firing

Question

I have a pretty simple collection, but I can't seem to bind to it's change event. In Chrome's console, I'm running:

var c = new AwesomeCollection(); c.bind("change", function(){   console.log('Collection has changed.'); });  c.add({testModel: "Test"}); // Shouldn't this trigger the above log statement? 

Since this is one of those things that can be difficult to track down, I doubt anybody knows off the top of their head what's going on (if so, great!). So, I'm asking two questions:

1. Should the above code work as anticipated?
2. If so, do you have any suggestions on how to track down where this would fail?

Thanks

Answer 1

The change event is only fired when one of the collections' models are modified. When a model is added to the collection the add event is fired.
See Backbone.js' Collection Documentation:

You can to bind "change" events to be notified when any model in the collection has been modified, listen for "add" and "remove" events[...]

To listen for when an add occurs modify your code to be

var c = new AwesomeCollection(); c.bind("add", function(){   console.log('Collection has changed.'); });  c.add({testModel: "Test"});  

Answer 2

No, that only raises the "add" event. It will raise the change event if you do this:

var c = new AwesomeCollection(); c.bind("change", function() {   console.log('Collection has changed.'); });  var model = new Backbone.Model({testModel: "Test"}); c.add(model); model.set({testModel: "ChangedTest"});