Appending empty query string param to the URL in Rails

Question

Is there a way to append something to the query string with no value set?

I would like to see this kind of URL being generated: http://local/things?magic.

What I'm looking for is when the user goes to http://local/other?magic then every URL in the generated page would contain magic in the end.

Following code is almost a solution but it gives me http://local/things?magic=. There is an extra = that I don't want there.

def default_url_options(options)
    if params.has_key?("magic")
        { :magic => "" }
    end
end

Setting { :magic => nil } will remove the magic entirely from the generated URLs.

Answer 1

Edited due to the changed question on the comment below:

Ah I see.

You could easily use the same URL for all devices and just separate by checking the request environment for HTTP_USER_AGENT.

But if this distinction is not enough (I think it is enough for more than 80% of all cases) you could do the following:

in config/routes.rb:

map.with_options :prefix => '/m', :format => 'mobile' do |mobile|
  mobile.resources :apples
  mobile.resource :user
  mobile.connect #...
end

# generates
# /m/apples
# /m/apples/new
# ...
# /m/user
# ... 

I have not tested this, but maybe you will have to add a MIME type mapping for :format => 'mobile'.

Answer 2

This is what cookies are for! cookies[:magic] = 'magic' and then it all automatically works just the way you're looking for. Not with URL query-string parameters, but whenever the browser requests another URL (until the browser is closed), it will include the cookie in the request.