Question

Hi I’m not sure how to do chained filters here. Here is my code

  before_filter :prepare_for_mobile
  protect_from_forgery

  private

  def mobile_device?
    request.user_agent =~ /Mobile|webOS/
  end
  helper_method :mobile_device?

  def prepare_for_mobile
    request.format = :mobile if mobile_device?
  end

What I want is after :prepare_for_mobile if it’s not a mobile device it will redirect to a normal website and I would like to check if the user is logged in. On mobile version, no users will be required to log in.

And in the normal website, I would like to :except a particular controller as well.

How do I do that?

Thanks a lot.

Answer 1

Well, a couple of things…. It looks like you’re partially implementing the solution from Railscasts.com here (only you’re trying to do it without setting the session parameter??).

You don’t need to ‘chain’ filters. Just create a new function (ex: get_ready) that calls the other two functions in the order you want them, and make that your filter.

before_filter :get_ready
protect_from_forgery

private

def get_ready
    prepare_for_mobile
    the_other_thing_you_want_to_chain
end

def mobile_device?
  request.user_agent =~ /Mobile|webOS/
end
helper_method :mobile_device?

def prepare_for_mobile
  request.format = :mobile if mobile_device?
end

def the_other_thing_you_want_to_chain
   do_something unless mobile_device?
end

If you want to branch behavior within a single site based on mobile, you should do that in the controllers, in the routes, or both. I hope I answered your questions.