Awesome Nested Input Formtastic Input Class

awesome_nested_set_input.rb

 class AwesomeNestedSetInput < Formtastic::Inputs::CheckBoxesInput
   def to_html
    unless options[:nested_set]
      super
    else
      nested_wrapping(options)
    end
  end

  def nested_wrapping(options)
    input_wrapping do
      choices_wrapping do
        legend_html <<
        hidden_field_for_all <<
        choices_group_wrapping do
          html_template_for_nested_set(options)
        end
      end
    end
  end

  def html_template_for_nested_set(options)
    if options[:show_current_first]
      model = reflection.options[:through].to_s.singularize.camelize.constantize
      additional_collection = options[:collection].first.class.where(
        :id => model.where(object.class.name.downcase.to_sym => object).pluck(:category_id)
      ).where(:parent_id => nil) rescue nil

      collection = additional_collection + options[:collection].where.not(:id => additional_collection.ids) rescue nil
    else
      collection = options[:collection]
    end

    if collection.present?
      collection.map{|menu|
        html_for_nested(menu)
      }.join("\n").html_safe
    end
  end

  def html_for_nested(menu, from_nested=false)
    choice = [menu.title, menu.id]
    first_wrap = choice_wrapping(choice_wrapping_html_options(choice)) do
      choice_html(choice) << sub_children(menu)
    end 
  end

  def sub_children(menu)
    template.content_tag( :ul,
     menu.children.collect do |child|
       html_for_nested(child, true)
     end.join("\n").html_safe, 
     {:class=>"sub_item-#{menu.id} sub-item"}
    )  unless menu.leaf?
  end
end