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

<%= form_for(OpenCashRegister.new, remote: true, :html => {:class=>"form-horizontal", :id=> "open_cash_register_form"}) do |f| %>
  <div class="portlet-body form">
    <div id="error_explanation"></div>
    <div class="row">
      <div class="col-md-12">
        <!-- caja registradora -->
        <div class="form-group">
          <%= f.label :cash_register_id, "Caja registradora", {:class=>"col-md-offset-1 col-md-3 control-label"} do %> Caja registradora
          <span class="required">*</span>
          <% end %>
          <div class="input-group col-md-4 select2-bootstrap-prepend">
            <% 
              available_cash = Array.new
              CashRegister.where(:pointsale_id => current_user.pointsale_id, :status => '1').find_each do |cash|
                is_opened = OpenCashRegister.where(:cash_register_id => cash.id, :status => '0').any?
                available_cash << cash if is_opened == false
              end
            %>
            <%= f.collection_select :cash_register_id, available_cash, :id, :name, {:prompt => "Seleccione"}, {:class => "form-control select2" } %>
          </div>
        </div> 
        <!-- initial cash -->
        <div class="form-group">
          <%= f.label :initial_cash, "Efectivo inicial", {:class=>"col-md-offset-1 col-md-3 control-label"} do %> Efectivo inicial <span class="required">*</span>
          <% end %> 
          <div class="col-md-4" style="padding-left: 0px;padding-right:0px">
            <%= f.number_field :initial_cash, {:class=>"form-control"} %>
          </div>
        </div>        
      </div>
    </div>
    <h4 class="form-section" style="margin:20px 0px 10px 0px"></h4>
    <div class="actions">
      <%= f.submit 'guardar', {:class=>"hidden"} %>
      <button type="button" class="btn btn-success" onclick="submitForm()" id="openCashButton" disabled>Abrir caja</button>
    </div>
  </div>
<% end %>
<script type="text/javascript">
  toastr.options = {
    "closeButton": false,
    "debug": false,
    "positionClass": "toast-top-center",
    "onclick": null,
    "showDuration": "1000",
    "hideDuration": "1000",
    "timeOut": "5000",
    "extendedTimeOut": "1000",
    "showEasing": "swing",
    "hideEasing": "linear",
    "showMethod": "fadeIn",
    "hideMethod": "fadeOut"
  }

  $('#open_cash_register_cash_register_id').on('change', function() {
    if ($(this).val() != "") {
      getCashFund( $(this).val() );
      $('#openCashButton').attr('disabled', false);

    } else {
      $('#openCashButton').attr('disabled', true);
    }
  });
  

  function submitForm() {   
    var cash = parseInt($('#open_cash_register_initial_cash').val());
    if ($('#open_cash_register_cash_register_id').val() != "") {
      $('#open_cash_register_form').submit();
    } else {
      toastr["warning"]("Se debe indicar efectivo inicial.");
    }  
  }

  function getCashFund(id) {
    $.ajax({
      type: "get",
      url:  '/cash_registers/' + id +'/get_cash_fund',
      dataType: 'json',
      success: function(data) {
        $('#open_cash_register_initial_cash').val(data);
      },      
    }); 
  }
</script>