backbone-events-1.js

  // A module that can be mixed in to *any object* in order to provide it with
  // custom events. You may bind with `on` or remove with `off` callback
  // functions to an event; `trigger`-ing an event fires all callbacks in
  // succession.
  //
  //     var object = {};
  //     _.extend(object, Backbone.Events);
  //     object.on('expand', function(){ alert('expanded'); });
  //     object.trigger('expand');
  //
  var Events = Backbone.Events = {

    // Bind one or more space separated events, or an events map,
    // to a `callback` function. Passing `"all"` will bind the callback to
    // all events fired.
    on: function(name, callback, context) {
      if (!(eventsApi(this, 'on', name, [callback, context]) && callback)) return this;
      this._events || (this._events = {});
      var list = this._events[name] || (this._events[name] = []);
      list.push({callback: callback, context: context, ctx: context || this});
      return this;
    },