Sort Backbone collection by key with direction. Works with both numeric and alphabetical values.

backbone_collection_sorting_example.js.coffee

MyApp.FooCollection = Backbone.Collection.extend(

  model: MyApp.Foo,

  sort_key: 'points',

  sort_direction: 'desc'

  comparator: (a, b) ->
    key_1 = a.get(@sort_key)
    key_2 = b.get(@sort_key)

    if Number(key_1) == parseInt(key_1)
      key_1 = parseInt(key_1)
      key_2 = parseInt(key_2)

    if @sort_direction == 'desc'
      return -1 if key_1 > key_2
      return 1 if  key_1 < key_2
      return 0
    else
      return 1 if key_1 > key_2
      return -1 if  key_1 < key_2
      return 0

)