Rails truncating of parameters with '.' in urls

Question

I am trying to send an IP address as a parameter to a Rails method destroy in a url. There is a problem if the parameter includes .; I get not found errors, this is the log generated:

Started DELETE "/admin/user/stefan-admin/whitelist/4.3.2.1" for 127.0.0.1 at 2013-07-17 09:31:18 +0100
Processing by ErrorsController#error_404 as 
  Parameters: {"not_found"=>"admin/user/stefan-admin/whitelist/4.3.2"}
WARNING: Can't verify CSRF token authenticity
Session: {:user=>"admin", :role=>:admin, :user_id=>"stefan-admin"}
Completed 404 Not Found in 30ms (Views: 1.1ms | ActiveRecord: 0.0ms)

The not found message has a truncated ip address. If I use a parameter without ., e.g. abc, I don't get the not found error, and the destroy method is called.

Rails received the url, but then mangled it internally, possibly because it is processing . as an extension. Is there some way to turn off this behaviour or escape the url to avoid it?

Answer 1

You need to add a constraint to the routes to allow dots in params

resources :whitelists, :constraints => { :id => /[0-9.]+/ }

Or something of that kind in your routes.rb, it depends on how you write your routes but the constraints part stay the same

Answer 2

The reason for the "truncated" ip address is the (optional) (.:format) that resources, 'get', 'match' etc. generate on every route.

You can specify a dedicate route without the format like:

match '/admin/user/:id/whitelist/*ip', to: 'controller#action', format: false

pay attention to the * at the last parameter. It collects the whole rest of the url.