Backbone model is undefined?

Question

I can't understand why this.model would be defined in view.intialize() when I run this.model.fetch() on it but not in view.render().

define([
  'jquery',
  'underscore',
  'backbone',
  'text!templates/example.html'
], function($, _, Backbone, exampleTemplate){

  var exampleView = Backbone.View.extend({
    el: $('body'),
    initialize: function() {
      this.model.set({ _id: this.options.user_id });
      this.model.fetch({
        success: this.render,
        error: function(model, response) {
          console.log('ERROR FETCHING MODEL');
          console.log(model);
          console.log(response);
        }
      });
    },
    render: function() {
      console.log('HELLO FROM RENDER');
      console.log(this.model);
      console.log('GOODBYE FROM RENDER');
    }
  });

  return exampleView;

});

Answer 1

It is because the this is being bound differently because render is being used as a callback, put the following line as the first line in your initialize method to bind this to the current view for the render method:

_.bindAll(this,"render");

Underscore.js bindAll function

Binds a number of methods on the object, specified by methodNames, to be run in the context of that object whenever they are invoked. Very handy for binding functions that are going to be used as event handlers, which would otherwise be invoked with a fairly useless this.