Is there a way to know if a page request came from the same application? - ruby-on-rails

Question

In Rails3, is there a way to check if the page I'm rendering now was requested from the same application, without the use of the hardcoded domain name?
I currently have:
def back_link(car_id = '')
# Check if search exists
uri_obj = URI.parse(controller.request.env["HTTP_REFERER"]) if controller.request.env["HTTP_REFERER"].present?
if uri_obj.present? && ["my_domain.com", "localhost"].include?(uri_obj.host) && uri_obj.query.present? && uri_obj.query.include?('search')
link_to '◀ '.html_safe + t('back_to_search'), url_for(:back) + (car_id.present? ? '#' + car_id.to_s : ''), :class => 'button grey back'
end
end
But this doesn't check for the "www." in front of the domain and all other possible situations.
It would also be nice if I could find out the specific controller and action that were used in the previous page (the referrer).

Answer 1

I think you're looking at this the wrong way.
If you look around the web, find a site with a search feature, and follow the link you'll see a param showing what was searched for.
That's a good way to do it.
Doing it by HTTP_REFERER seems a bit fragile, and won't work, for example, from a bookmark, or posted link.
eg.
/cars/12?from_search=sports+cars
then you can just look up the params[:from_search]
If you really need to do it by HTTP_REFERER then you probably dont have to worry about subdomains. Just;
def http_referer_uri
request.env["HTTP_REFERER"] && URI.parse(request.env["HTTP_REFERER"])
end
def refered_from_our_site?
if uri = http_referer_uri
uri.host == request.host
end
end
def refered_from_a_search?
if refered_from_our_site?
http_referer_uri.try(:query)['search']
end
end

Answer 2

Try something like this:
ref = URI.parse(controller.request.env["HTTP_REFERER"])
if ref.host == ENV["HOSTNAME"]
# do something
To try and get the controller/action from the referring page:
ActionController::Routing::Routes.recognize_path(url.path)
#=> {:controller => "foo", :action => "bar"}

Answer 3

Create an internal_request? method utilizing request.referrer.
Compare the host and port of the request.referrer with your Application's host and port.
require 'uri' # Might be necesseary.
def internal_request?
return false if request.referrer.blank?
referrer = URI.parse( request.referrer )
application_host = Rails.application.config.action_mailer.default_url_options[ :host ]
application_port = Rails.application.config.action_mailer.default_url_options[ :port ]
return true if referrer.host == application_host && referrer.port == application_port
false
end
And then call it like this where you need it, most likely in application_controller.rb:
if internal_request?
do_something
end
Some caveats:
This might need to be modified if you're using subdomains. Easy, though.
This will require you to be setting your host and port for ActionMailer in your configuration, which is common.
You might want to make it the reverse, like external_request? since you're likely handling those situations uniquely. This would allow you to do something like this:
do_something_unique if external_request?