<%#new articles starts with two choices fields %>
<% if @article.new_record? %>
<%= required text_area_tag 'article[choices][]', '', :id => 'choice1' %>
<%= required text_area_tag 'article[choices][]', '', :id => 'choice2' %>
<% else #already saved pairwise content show one input for each choice%>
<% @article.choices.each do |choice_hash| %>
<% choice_hash.each do |id, data| %>
<%= required text_area_tag "article[choices_saved[#{id}]",
data, :id => "choice_#{id}", :disabled => false %>
<% end %>
<% end %>
<% end %>