Strong parameter does not work when i new model and controller in spree '3-0-stable' and rails 4.2 -

how add new fields spree::pre_order in spree-3.0 + rails4 ?

like old customization: ==========================

app/controllers/spree/api/pre_order_controller

class preordercontroller < spree::api::basecontroller

def create     @pre_order = preorder.new(pre_order_params)     if @pre_order.save     end     respond_with(@pre_order) end  private def pre_order_params   params.require(:pre_order).permit(:user_id,:is_order_created)  end 

end

i got following error

{ "exception": "param missing or value empty: pre_order" }

please let me know comments.