Rails CORS setting

controller_example.rb

before_action :cors_preflight_check
    after_action :cors_set_access_control_headers

    def cors_set_access_control_headers
      headers['Access-Control-Allow-Origin'] = '*'
      headers['Access-Control-Allow-Methods'] = 'POST, GET, PUT'
      headers['Access-Control-Max-Age'] = "1728000"
    end

    def cors_preflight_check
      if request.method == :options
        headers['Access-Control-Allow-Origin'] = '*'
        headers['Access-Control-Allow-Methods'] = 'POST, GET, OPTIONS'
        headers['Access-Control-Allow-Headers'] = 'X-Requested-With, X-Prototype-Version'
        headers['Access-Control-Max-Age'] = '1728000'
        render :text => '', :content_type => 'text/plain'
      end
    end