Rails fields_for form not showing up

Question

products_controller.rb

def new
  @product = Product.new
  @product.build_discount
end

product.rb

has_many :discounts, :dependent => :destroy
accepts_nested_attributes_for :discounts
attr_accessible :discounts_attributes

discount.rb

belongs_to :product

_edit_product.html.erb

<%= form_for(product, :html => { :multipart => true  }, :remote => true) do |f| %>
    // STUFF
    <%= f.fields_for :discounts do |discount_form| %>
       //does not show up
    <% end %>
<% end %>

The content in the fields_for block does not show up. However, if I change has_many :discounts to has_many :discount, the form shows up (get mass assignment error when I try to submit).

Any ideas as to why the form is not rendering in the fields_for block and why it does render when I change the pluralization?

Answer 1

Do you want many discounts or one discount?

@product.build_discount is used in a has_one association, but the rest of your code is for has_many

If you want many discounts then change it to @product.discounts.build

Otherwise, if you want just one discount, change the following:

f.fields_for :discount do |discount_form| and accepts_nested_attributes_for :discount to singular.

@products.discounts.build won't work because you can't get an association from a collection of objects. For example:

@products = Product.all
@discount = @products.discounts.build
# This won't work! You'll get an error

@product = Product.find(params[:id])
@discount = @product.discounts.build
# This will work, since you're running it on a single instance of Product

Answer 2

How are you passing the local variable product to your _edit_product.html.erb partial? I'm guessing you have a new.html.erb view where you render your partial?

Answer 3

Using @mind_blank's answer, I wrote this solution:

@products = current_user.products.each {|product| product.discounts.build}

The form showed up after this line.