Rails：嵌套表单-将user_id从父对象传递给子对象

Question

I'm trying to pass the user_id from the parent model ( Order ) to the child model ( Sale ). As this does not work the "normal" way, like @sale.user_id = current_user.id (this actually works for the parent model Order with @order.user_id = current_user.id ). I tried this in my model as a workaround:

class Sale < ActiveRecord::Base
  belongs_to :order
  before_create :user

  def user
    self.user_id = Order.where(:id => self.order_id).pluck(:user_id)
  end

end

Within user I'm comparing the Order .id (parent) with the Sale .order_id (child) as the order_id gets saved within a Sale record. When I look up the last Sale record, the user_id is always nil .

class SalesController < ApplicationController
 load_and_authorize_resource
 before_action :authenticate_user!

 def create
   @order = Order.find(params[:order_id])
   @sale = @order.sales.create(params[:sale].permit(:product, :product_group, :discount, :order_id, :user_id, :multiplier))
   redirect_to order_path(@order)
 end

Do you have an Idea?

Answer 1

Try this in your model.

 def user
   self.user_id = self.order.user_id
 end

Answer 2

params[:sale].permit(:product, :product_group, :discount, :order_id , :user_id , :multiplier)

Firstly, you should not permit user_id & order_id in your controller.

Secondly, you can populate your Sale's user_id as follow:

def user
  user_id = order.user_id
end