class ActiveAdmin::FormBuilder

def has_many(association, options = {}, &block)
  options = { :for => association, :new_record => true }.merge(options)
  options[:class] ||= ""
  options[:class] << "inputs has_many_fields"
  # Add Delete Links
  form_block = proc do |has_many_form|
    # @see https://github.com/justinfrench/formtastic/blob/2.2.1/lib/formtastic/helpers/inputs_helper.rb#L373
    contents = if block.arity == 1  # for backwards compatibility with REE & Ruby 1.8.x
      block.call(has_many_form)
    else
      index = parent_child_index(options[:parent]) if options[:parent]
      block.call(has_many_form, index)
    end
    if has_many_form.object.new_record?
      contents += template.content_tag(:li, :class => 'has_many_delete') do
        template.link_to I18n.t('active_admin.has_many_delete'), "#", :onclick => "$(this).closest('.has_many_fields').remove(); return false;", :class => "button"
      end
    elsif options[:allow_destroy]
      has_many_form.input :_destroy, :as => :boolean, :wrapper_html => {:class => "has_many_remove"},
                                                      :label => I18n.t('active_admin.has_many_remove')
    end
    contents
  end
  form_buffers.last << with_new_form_buffer do
    template.content_tag :div, :class => "has_many #{association}" do
      # Allow customization of the nested form heading
      unless options.key?(:heading) && !options[:heading]
        form_heading = options[:heading] ||
          object.class.reflect_on_association(association).klass.model_name.human(:count => 1.1)
        form_buffers.last << template.content_tag(:h3, form_heading)
      end
      inputs options, &form_block
      js = options[:new_record] ? js_for_has_many(association, form_block, template) : ""
      form_buffers.last << js.html_safe
    end
  end
end