Question

In my code below I want to assign the current user to the products that are created.

ProductsController.rb

def new
  @products = Array.new(2) { Product.new }   
end

def create_multiple
  params[:product][:user_id] = current_user.id
  Product.transaction do
    begin
      @products = Product.create!(params[:products].map {|_k, up| up.merge params[:product]})
      redirect_to :back, :notice => "Success!"
    rescue ActiveRecord::Rollback
      redirect_to :back, :notice => "An error occured, please try again."
    end
  end
end

new.html.erb

<%= form_tag create_multiple_products_path, :method => :post do %>

  <%= date_select("product", "purchase_date")  %>

  <% @products.each_with_index do |product, index| %>
     <%= fields_for "products[#{index}]", product do |up| %>
        <%= render "fields", :f => up %>
     <% end %>
  <% end %>

  <%= submit_tag "Done" %>
<% end %>

The USER ID (current user) isn’t being assigned. Any ideas on how to assign it?

Answer 1

You can eliminate a lot of logic here by remembering two facts: create will take an array of Hashes to create multiple objects, and its bang-method counterpart create! will throw an exception if any validations failed.

def create_multiple
  # like clyfe said, do this in a transaction
  Product.transaction do
    begin
      @products = current_user.products.create!(
        # Hash#map returns an Array, so no need to use Hash#values
        params[:products].map { |_k, up| up.merge params[:product] }
      )

      # if create! is successful...
      redirect_to :back, :notice => "Success!"

    # if it's not successful it'll throw this exception, which we can rescue
    rescue ActiveRecord::Rollback
      redirect_to :back, :notice => "An error occured, please try again."
    end
  end
end

---

One way to get deal with the create! issue is to just get rid of any “blank” entries in a before_filter, e.g.:

before_filter :toss_blank_products

def toss_blank_products
  params[:products].reject! do |prod|
    # this logic may need to be more complex depending on the meaning of "blank"
    # for your model/form
    prod.values.all? &:blank
  end
end