For BackboneRails series. Code that adds the CSRF token to CRUD requests automatically, merged with the original sync config file by BackboneRails.

sync.js.coffee

do (Backbone) ->
  Backbone._sync = Backbone.sync

  Backbone.sync = (method, entity, options={}) ->
    _.defaults options,
      beforeSend: _.bind( methods.beforeSend, entity )
      complete:   _.bind( methods.complete,   entity )

    if method is 'create' or method is 'update' or method is 'put' or method is 'delete'
      options.headers ?= {}
      options.headers["X-CSRF-Token"] = $("meta[name='csrf-token']").attr 'content'

    sync = Backbone._sync(method, entity, options)

    if !entity._fetch and method is "read"
      entity._fetch = sync

    sync

  methods =
    beforeSend: ->
      @trigger "sync:start", @

    complete: ->
      @trigger "sync:stop", @