document_helper.rb

_contribution_fields.html.haml

- f.semantic_fields_for :contributions, obj, :child_index => i do |child_form|
    = child_form.input :person_id, :collection => Person.all.collect { |p| [p.name, p.id]}, :include_blank => false, :label => 'Contributor Name'
    = child_form.input :name, :label => 'Type'

_form.html.haml

- semantic_form_for @document, :html => {:multipart => true} do |f|
  - f.inputs do
    = f.input :tag_list
    %li.tags
      %label available tags
      = tag_collection_select
    = f.input :doctype, :collection => Document::Types, :include_blank => false, :label => "Type"
    = f.input :title
    = f.input :short_name, :required => false
    = f.input :published_on
    #contributors
      - @document.contributions.each do |c|
        - unless c.new_record?
          .nested
            - f.semantic_fields_for :contributions, c do |child_form|
              = child_form.label c.name
              = c.person.name + " " + link_to('[X]', '#', :class => 'remove')
              = child_form.input(:_destroy, :as => :hidden)
    %li
      %label  
      = add_contribution_link(f,@document)

    = f.input :cost, :required => false

document_helper.rb

module DocumentHelper
  def add_contribution_link(f,doc)
    link_to_function "Add Contributor" do |page|
      html = render 'contribution_fields', :f => f, :obj => doc.contributions.build, :i => 'NEW'
      page << "$('#contributors').append('#{escape_javascript(html)}'.replace(/NEW/g, new Date().getTime()));"
    end
  end
end