Question

Just wondering why this works:

window.NewListView = Backbone.View.extend({
  template: _.template('<a href="/list" class="button new-list">Create New List</a>'),

  render: function(){
    $(this.el).html(this.template());
    return this;
  }
});

window.List = new (Backbone.Router.extend({
  routes: { "": "index" },

  initialize: function(){
    this.newListView = new NewListView();
  },

  start: function(){
    Backbone.history.start();
  },

  index: function(){
    $('.lists').append(this.newListView.render().el);
  }
}));

$(function(){ List.start(); })

And this doesn’t:

window.NewListView = Backbone.View.extend({
  template: _.template('<a href="/list" class="button new-list">Create New List</a>'),

  render: function(){
    $(this.el).html(this.template());
    return this;
  }
});

window.List = new (Backbone.Router.extend({
  routes: { "": "index" },

  initialize: function(){
    this.newListView = new NewListView();
    $('.lists').append(this.newListView.render().el);
  },

  start: function(){
    Backbone.history.start();
  },

  index: function(){

  }
}));

$(function(){ List.start(); })

The difference is just moving

$('.lists').append(this.newListView.render().el);

between initialize() and index() of the router.

Answer 1

Its because of the way, and when, you’re creating an instance of your router.

When you do:

window.List = new (Backbone.Router.extend({...

You’re creating an instance of the router before the DOM is loaded. Therefore, in your initialize function, your jQuery selector is not returning any nodes.

If you open up a console, you can see the order of operations logged to it on this jsFiddle:

http://jsfiddle.net/edwardmsmith/x64hw/

window.NewListView = Backbone.View.extend({
  template: _.template('<a href="/list" class="button new-list">Create New List</a>'),

  render: function(){
    $(this.el).html(this.template());
    return this;
  }
});

window.List = new (Backbone.Router.extend({
  routes: { "": "index" },

  initialize: function(){
    this.newListView = new NewListView();
    console.log("List Initialize");
    $('.lists').append(this.newListView.render().el);
  },

  start: function(){
    Backbone.history.start();
  },

  index: function(){

  }
}));

$(function(){ 
    console.log("Before List Start");
    List.start(); 
    console.log("After List Start");

})​

Results in:

List Initialize
Before List Start
After List Start

But, if you create your router instance after the DOM loads:

window.NewListView = Backbone.View.extend({
  template: _.template('<a href="/list" class="button new-list">Create New List</a>'),

  render: function(){
    $(this.el).html(this.template());
    return this;
  }
});

window.List = Backbone.Router.extend({
  routes: { "": "index" },

  initialize: function(){
    this.newListView = new NewListView();
    console.log("List Initialize");
    $('.lists').append(this.newListView.render().el);
  },

  start: function(){
    Backbone.history.start();
  },

  index: function(){

  }
});

$(function(){ 
    console.log("Before List Start");
    list = new List();                
    list.start(); 
    console.log("After List Start");

})​

The order is as you would expect, and it works:

Before List Start
List Initialize
After List Start

as shown in this jsFiddle:

http://jsfiddle.net/edwardmsmith/eDWfh/