Question

I have a rails app, with two separate DB tables, users and products. A user has_many products, and a product belongs_to a user.

When I create a product, I want it to automatically add the user_id to the user_id database column in the products table. What changes to my mvc do I need to make to ensure that the correct user_id is added when a new product is created?

Answer 1

Just as a suggestion, you may want to go back and accept the answers to some of your previous questions, which will improve your response rate and increase the likelihood someone will answer your questions in the future.

There are a few ways to do this, one approach:

Create current user function

class ApplicationController < ActionController::Base
  private
  # Finds the User with the ID stored in the session with the key
  # :current_user_id This is a common way to handle user login in
  # a Rails application; logging in sets the session value and
  # logging out removes it.
  def current_user
    @_current_user ||= session[:current_user_id] &&
      User.find_by_id(session[:current_user_id])
  end
end

http://guides.rubyonrails.org/action_controller_overview.html#session

Make sure to be cognizant of security concerns. A gem like Devise can also help.

Add to products controller

class ProductsController < ApplicationController
  def create
    current_user.products.create! params[:product]   # make sure attr_accessible is setup on products
  end
end