Check if @attributes already exists, just set it if not exists.

app/assets/javascripts/app/controllers/_application_controller_form.js.coffee

@@ -13,6 +13,7 @@ class App.ControllerForm extends App.Controller
       @form = @formGen()
     if !@model
       @model = {}
+    if !@attributes
       @attributes = []
 
     # if element is given, prepend form to it