<%= render 'btn_dec', id: f.object.product_id %> <%= f.text_field :count, class: 'form-control row_counter', value: 0 %> <%= f.hidden_field :price, value: f.object.product.price, class: :price %> <%= render 'btn_inc', id: f.object.product_id %> <%= f.hidden_field :product_id %>