骨干绑定以在集合上添加事件

Question

I have problem with backbone collections. I trying to listen all events on collection:

  this.collection.on('all', function(ev) {
    console.log(ev);
  });

And collection trigger event only when I create record like this:

  this.collection.create({name: 'aloha'});

But not when I create model instance directly:

  var room = new Room({name: 'hello'}); // this code not trigger any events on collection
  room.save();

I am new to Backbone, but I think that second code should trigger event. Can somebody help me? Thanks!

Answer 1

The event is not triggered on the collection, because the room model is not associated (ie has not been added) to this.collection .

Assuming you have defined your model and collection similar to:

var Room = Backbone.Model.extend();

var Rooms = Backbone.Collection.extend({
  model:Room
});

var rooms = new Rooms();

rooms.on('all',function(eventName) {
  console.log(eventName);
});

For your code to work as expected you would have to add the room model to the rooms collection such as:

var room = new Room({'name':'hello'});

// This will trigger the add event on the collection
rooms.add(room);

// save the model
room.save();

The following is short-hand for the above code block:

var room = rooms.create({'name':'hello'});

Here is a FIDDLE showing the behavior.