What events are triggered when calling fetch() on a Backbone.js collection?

In my backbone.js app, there is a Trips collection that holds Trip models, which is working with LocalStorage. I am able to call Trips.create(form_attributes) to create and save a trip to the Todos store.

When I first load my app, I call Trips.fetch({ success: trips_fetch_success }), and trips_fetch_success receives a response that shows the Trip models that the Trips collection holds.

I have tried to bind refresh and change events to the Trips collection,开发者_StackOverflow中文版 but these events are not being caught, making me believe I have the wrong idea about which events Trips.fetch triggers.

My question: which events should Trips.fetch trigger? And are the events triggered on the collection or on each of the individual Trip models?

Collection.fetch() will call reset on success, which in turn will trigger a 'reset' event. Any subscribers to the collections reset event should receive the event.

The key here is "on success." I had this problem, only to discover that backbone was silently swallowing my errors messages. Pass in an error handler that, at least, logs to console.log(), and see what's happening:

trips.fetch({error: function() { console.log(arguments); }});

(Note: Old versions of backbone.js will trigger "refresh" instead of "reset")

If you are using backbone 1.0, you'll need to pass reset:true in the fetch() call in order to bind with the reset event:

trips.fetch({reset: true});

As of backbone 1.0, model.fetch() triggers a 'sync'. That's what you should bind to.

Here's the relevant part from the backbone.js source where the 'sync' event is fired:

fetch: function(options) {
  options = options ? _.clone(options) : {};
  if (options.parse === void 0) options.parse = true;
  var model = this;
  var success = options.success;
  options.success = function(resp) {
    if (!model.set(model.parse(resp, options), options)) return false;
    if (success) success(model, resp, options);

    // HERE'S THE TRIGGER!
    model.trigger('sync', model, resp, options);

  };
  wrapError(this, options);
  return this.sync('read', this, options);
},