resulting HTML

_edit.block.html.haml

= link_to t("lpl.manipulate.destroy"), block_path(blck.object.id), :method => :delete, :confirm => t('lpl.delete.block.confirm'), :remote => true, :class => 'remove-block'

= blck.fields_for :contents do |cntnt|
  %div{ :class => "lpl content #{blck.object.kind}", :data => { :lpl_language => cntnt.object.language, :lpl_content => "localized" } }
    = cntnt.hidden_field  :id, :class => "block-id"

_form.html.haml

        = f.fields_for :blocks, @page.blocks.order_by(:position.asc).to_ary do |blck|
          %li{ :class => 'lpl-block', :data => { :lpl_type => 'block' }}
            %div{ :class => 'handle' }
            = render :partial => "edit_block", :locals => { :blck => blck }

gistfile1.html

<li class="lpl-block" data-lpl_type="block" data-lpl_block_id="4d63ce70d164a90a2c000165">
  <a href="/lpl/blocks/4d63ce70d164a90a2c000164" class="remove-block" data-confirm="Inhalt wird gelöscht—sind sie sicher?" data-method="delete" data-remote="true" rel="nofollow">Entfernen</a>
<!-- mmore stuff in here -->
  <input class="block-id" id="page_blocks_attributes_0_contents_attributes_0_id" name="page[blocks_attributes][0][contents_attributes][0][id]" type="hidden" value="4d63ce70d164a90a2c000165">
</li>