javascript - Coffeescript & Backbone.js - TypeError: this._ensureElement is not a function

Question

.: EDIT :. If you are having the same problem check your variable initialization, i forgot about new.

I keep getting TypeError: this._ensureElement is not a function and got TypeError: this._reset is not a function once earlier but I can't really recreate the exact setup for the latter.

I have my scripts in right order:

<script src="js/components/jquery.js"></script>
<script src="js/components/underscore.js"></script>
<script src="js/components/backbone.js"></script>
<script src="js/script.js"></script>

My model is registered before my collection.

It's a shopping cart app.

#namespacing

App =
  Collection : {}
  Model : {}
  View : {}

###
MODEL
###

class ModelItem extends Backbone.Model

  #default values

  defaults:
    name : 'Product Name' 
    quantity : 0
    unit : 'kg'

  #Increase or decrease the quantity

  change_quantity : (type) ->
    qty = @get 'quantity'
    @set 'quantity', if type is 'increase' then ++qty else --qty

###
COLLECTION
###

class CollectionItems extends Backbone.Collection

  model: ModelItem

###
VIEW
###

class ViewItems extends Backbone.View

window.view = ViewItems()
window.item = ModelItem()

Answer 1

You're missing the new operator.

window.view = new ViewItems()
window.item = new ModelItem()