Rails 4 nested attributes multiple records when updating - ruby-on-rails

Question

I'm stuck and I don't know why it is not working right.
I have a model product which has many tags.
When I update the product rails update properly the products attributes but is creating another tag record instead of just updating it.
here is my code:
View form:
<%= form_for ([#product.user, #product]), id: 'edit_form' do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<div class="field">
<%= f.label :name %><br>
<%= f.text_field :name %>
</div>
<div class="field">
<%= f.label :description %><br>
<%= f.text_area :description %>
</div>
<div class="field">
<%= f.fields_for :tags do |t| %>
<%= t.label :name %>
<%= t.text_field :name %>
<% end %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
product model:
class Product < ActiveRecord::Base
belongs_to :user, :foreign_key => "user_id"
has_many :tags, :dependent => :destroy
accepts_nested_attributes_for :tags, reject_if: :all_blank, allow_destroy: true, :update_only => true
end
tags model:
class Tag < ActiveRecord::Base
belongs_to :product, :foreign_key => "product_id"
# before_save { name.downcase! }
end
product controller:
def edit
user = User.find(params[:user_id])
#product = user.products.find(params[:id])
#tags = #product.tags.all
respond_to do |format|
format.html
format.js
end
end
def update
user = User.find(params[:user_id])
#product = user.products.find(params[:id])
#tags = #product.tags.all
respond_to do |format|
if #product.update(product_params)
format.html { redirect_to([#product.user, #product], :notice => 'Product successfully updated.') }
else
format.html { render :action => "edit" }
end
end
end
def product_params
params.require(:product).permit(:name, :description, tags_attributes: :name)
end

Answer 1

You have to pass the tag id in the permit params in your controller
def product_params
params.require(:product).permit(:name, :description, tags_attributes: [:id,:name])
end