replacement for redirect_to(:back) that works even if no referer (e.g. via direct url)

back_default_redirect.rb

# same as redirect_to(:back) but works even if no referer (e.g. via direct url)
# include this module to ApplicationController
module BackDefaultRedirect
  protected

  # use as redirect_to back_or_default(root_url)
  def back_or_default(default = '/')
    referer = request.env['HTTP_REFERER']
    # if has HTTP_REFERER and it not equals current url
    if referer && !referer.include?(request.request_uri)
      :back
    else
      default
    end
  end

  def redirect_to_back(default = '/')
    redirect_to back_or_default(default)
  end

end