foodsoft/app/views/shared/_article_fields_price.html.haml

.fold-line
  = f.input :price do
    .input-prepend
      %span.add-on= t 'number.currency.format.unit'
      = f.input_field :price, class: 'input-mini'
  = f.input :tax do
    .input-append
      = f.input_field :tax, class: 'input-mini'
      %span.add-on %
.fold-line
  = f.input :deposit do
    .input-prepend
      %span.add-on= t 'number.currency.format.unit'
      = f.input_field :deposit, class: 'input-mini'
  .control-group
    %label.control-label{for: 'article_fc_price'}
      = Article.human_attribute_name(:fc_price)
    .controls.control-text#article_fc_price
      = number_to_currency(f.object.fc_price) rescue nil

-# do this inline, since it's being used in ajax forms only
- field = f.object.class.model_name.to_s.underscore
:javascript
  var form = $('#article_fc_price').closest('form');
  $('##{field}_price, ##{field}_tax, ##{field}_deposit', form).on('change keyup', function() {
    var price = parseFloat($('##{field}_price', form).val());
    var tax = parseFloat($('##{field}_tax', form).val());
    var deposit = parseFloat($('##{field}_deposit', form).val());
    // Article#gross_price and Article#fc_price
    var gross_price = (price + deposit) * (tax / 100 + 1);
    var fc_price = gross_price  * (#{FoodsoftConfig[:price_markup].to_f} / 100 + 1);
    $('#article_fc_price').html($.isNumeric(fc_price) ? I18n.l("currency", fc_price) : '…');
  });