POS-Server/app/views/pre_sales/_form.html.erb

<%= form_for(PreSale.new, remote: true) do |f| %>
  <%= f.hidden_field :customer_id  %>
  <%= f.hidden_field :user_id %>  
  <%= f.hidden_field :open_cash_register_id %>   
  <%= f.hidden_field :sale_type %>   
  <%= f.hidden_field :product_id %> 
  <%= f.hidden_field :quantity %>     
  <%= f.hidden_field :amount %>   
  <%= f.hidden_field :tax %>   
  <%= f.hidden_field :discount %>   
  <%= f.hidden_field :total %>   
  <%= f.submit  'save', {:class=>"hidden"}%>
<% end %>