Rails FormBuilder to be used with Bootstrap from Twitter

BootstrapFormBuilder.rb

class BootstrapFormBuilder < ActionView::Helpers::FormBuilder  
  ['text_field', 'text_area'].each do |helper|
    define_method helper do |field, *args|
      options = args.detect{ |a| a.is_a?(Hash) } || {}
      
      if @object.errors[field].any?
        '<div class="clearfix error">'.html_safe +
        (self.label field) +
        '<div class="input">'.html_safe +
        (super field, *args) +
        '<span class="help-inline">'.html_safe + @object.errors[field].join('; ') + '</span>'.html_safe +
        '</div></div>'.html_safe
      else
        '<div class="clearfix">'.html_safe +
        (self.label field) +
        '<div class="input">'.html_safe +
        (super field, *args) +
        '</div></div>'.html_safe
      end
      
    end
  end
end