app/views/cdx/admin/shared/_nested_asset_form.html.erb
<% if defined?(f) && defined?(association) %>
<div class="form-group">
<label class="col-sm-2 control-label select"><%= f.object.class.human_attribute_name association %></label>
<div class="col-sm-10">
<div id="nested-asset-form">
<%= f.simple_fields_for association do |image_form| %>
<%= render partial: 'cdx/admin/shared/nested_asset_fields', locals: { f: image_form } %>
<% end %>
<div class="links">
<%= link_to_add_association fa_icon(:plus) + ' ' + t('admin.actions.new'), f, :images, class: 'btn btn-info', partial: 'cdx/admin/shared/nested_asset_fields' %>
</div>
</div>
</div>
</div>
<% end %>