Uploading Files with CORS and Ember.js

gistfile1.coffee

# View
RoscredAdmin.UploadFileView = Ember.TextField.extend
  classNames: ['form-control']
  attributeBindings: ['name']
  type: 'file'
  file: null
  change: (event)->
    fd = new FormData()
    fd.append('pdf', event.target.files[0])
    @set('file', fd)

# Controller
App.OtherController = Ember.Controller.extend
  agreementPdf: null
  actions:
    savePdf: ->
      return unless @get('agreementPdf')
      $.ajax 
        url: "/pdf/upload_agreement",
        type: 'POST'
        contentType: false
        processData: false
        data: @get('agreementPdf')
        # don't forget about CORS options

        

gistfile2.handlebars

# Emblem
RoscredAdmin.UploadFileView name="pdf" file=pdf
button click="savePdf" Save

gistfile3.rb

class PdfController < ApplicationController

  def upload
    File.open("public/uploads/some.pdf", "wb") { |file| file.write params[:pdf].read }
    head :ok
  end
end