The other day I needed to use a view helper in my controller in order to nicely format a flash message. It turns out that it’s a simple thing to do.

In my particular case, I had a helper to format a phone number using the phony gem.

  # app/helpers/application_helper.rb
  def format_phone(phone_number)
    unless phone_number.nil?
      Phony.formatted(phone_number, spaces: '-')

Once you have your view helper, you can use it in any rails controller by invoking the view_context object:

  # app/controllers/phones_controller.rb
  def confirm
    if current_user.confirmed_phone?
      redirect_to edit_phone_path,
        notice: \
          "The phone number #{view_context.format_phone(}
          is already confirmed."

You can see more about the view_context object in the api dock.