openproject/app/views/deliverables/_deliverable_cost.rhtml

<%- 
  index ||= "INDEX" 
  new_or_existing = deliverable_cost.new_record? ? 'new' : 'existing'
  id_or_index = deliverable_cost.new_record? ? index : deliverable_cost.id 
  prefix = "deliverable[#{new_or_existing}_deliverable_cost_attributes][]"
  id_prefix = "deliverable_#{new_or_existing}_deliverable_cost_attributes_#{id_or_index}"
  
  @deliverable_cost = deliverable_cost
  error_messages = error_messages_for 'deliverable_cost'
-%> 

<% unless error_messages.blank? %><tr><td colspan="4"><%= error_messages %></td></tr><% end %>
<tr class="cost-entry" id="<%= id_prefix %>">
  <% fields_for prefix, deliverable_cost do |cost_form| %>
  <td class="cost_units">
    <%= cost_form.text_field :units, :index => id_or_index, :size => 3 %>
    <span id="<%= "#{id_prefix}_unit_name" %>">
      <%=h deliverable_cost.cost_type.unit_plural %>
    </span>
  </td>
  <td>
    <%= cost_form.select :cost_type_id, cost_types_collection_for_select_options, {}, {:index => id_or_index} %>
    <%= cost_form.hidden_field :rate_id, :index => id_or_index %>
    <%= observe_field( "#{id_prefix}_cost_type_id", :url => {:action => :update_deliverable_cost}, :with => "'cost_type_id=' + encodeURIComponent(value) + '&units=' + encodeURIComponent(document.getElementById('#{id_prefix}_units').value) + '&element_id=#{id_prefix}'") %>
    <%= observe_field( "#{id_prefix}_units", :frequency => 1, :url => {:action => :update_deliverable_cost}, :with => "'cost_type_id=' + encodeURIComponent(document.getElementById('#{id_prefix}_cost_type_id').value) + '&units=' + encodeURIComponent(value) + '&element_id=#{id_prefix}'") %>
  </td>
  <% if User.current.allowed_to?(:view_unit_price, @project)%>
  <td class="currency">
    <span id="<%= "#{id_prefix}_costs" %>"><%= number_to_currency(deliverable_cost.costs) %></span>
  </td>
  <% end %>
  <td align="center">
    <%= image_to_function 'delete.png', "deleteDeliverableCost('#{id_prefix}')" %>
  </td>
  <% end %>
</tr>