application_helper.rb

## subclass for chained labelling methods
class LabellingFormBuilder < ActionView::Helpers::FormBuilder
  include ActionView::Helpers::TagHelper
  def text_field_with_labelling( method, options={})
    label(method) + text_field_without_labelling( method, options)
  end
  alias_method_chain :text_field, :labelling

  def date_select_with_labelling( method, options={}, html_options={})
    label(method) + date_select_without_labelling( method, options, html_options)
  end
  alias_method_chain :date_select, :labelling

  def collection_select_with_labelling( method, collection, value_method, text_method, options = {}, html_options = {})
    label(method) + collection_select_without_labelling( method, collection, value_method, text_method, options, html_options)
  end
  alias_method_chain :collection_select, :labelling
end

## adding new "auto_complete" methods to the root FormBuilder
class ActionView::Helpers::FormBuilder
  include ActionView::Helpers
  def text_field_with_auto_complete( method, options={})
    tag = InstanceTag.new(object_name, method, self, options.delete(:object))
    tag_id = tag.send(:tag_id)
    ac_tag_id = "#{tag_id}_auto_complete"

    text_field( method, options ) +
      content_tag( :div, '', :class => 'auto_complete', :id => ac_tag_id) +
      javascript_tag( %{new Ajax.Autocompleter('#{tag_id}', '#{ac_tag_id}', '/cities', {method:'get',paramName:'city[name]',afterUpdateElement:getSelectionId})})
  end

  def answer_field( question, options={})
    method = question.answer_id.to_s
    i = method.split('_').last.to_i

    output = ''
    question.choices.each do |choice|
      output << content_tag( :div,
        radio_button( method, choice.id ) + label( "#{method}_#{choice.id}", h(choice.content) ),
        :class => "subelement" ) + "\n"
    end
    return output
  end
end