anchor.diff:  <% unit_id = sample_attribute ? sample_attribute.unit_id : nil %>
   <% template_column_index = sample_attribute ? sample_attribute.template_column_index : nil %>
   <% field_name_prefix = "sample_type[sample_attributes_attributes][#{index}]" %>
  -<% is_controlled_vocab = sample_attribute && sample_attribute.sample_attribute_type.try(:controlled_vocab?) %>
   <% constraints = sample_type.editing_constraints %>
   <% allow_required = constraints.allow_required?(sample_attribute) %>
   <% allow_attribute_removal = constraints.allow_attribute_removal?(sample_attribute)  %>
  
positive.code:                                       attribute_type_id),
                     :class => 'form-control sample-type-attribute-type',
                     disabled:!allow_type_change %>
      <div class='controlled-vocab-block' style="<%= 'display:none;' unless is_controlled_vocab %>">
        <br/>
        <%= select_tag "#{field_name_prefix}[sample_controlled_vocab_id]",
                       options_for_select(SampleControlledVocab.all.map { |t| [t.title, t.id] },
  
negative.code:                      :class => 'form-control controlled-vocab-selection' %>
          <%= create_sample_controlled_vocab_model_button %>
      </div>
      <div class='sample-type-block' style="<%= 'display:none;' unless sample_attribute.try(:seek_sample?) %>">
        <br/>
        <%= select_tag "#{field_name_prefix}[linked_sample_type_id]",
                       grouped_options_for_select(sample_type_grouped_options,
  