default_url_options and rails 3

I believe the preferred method is to now tell the router to handle this:

Rails.application.routes.default_url_options[:foo]= 'bar' 

You can put this line in either routes.rb or an initializer. Whichever you would prefer. You could even put it in your environment configs if the values change based on your environment.

That apidock.com link is misleading. default_url_options is not deprecated.

http://guides.rubyonrails.org/action_controller_overview.html#default_url_options

To set url options for current request use something like this in your controller:

class ApplicationController < ActionController::Base

  def url_options
    { :profile => current_profile }.merge(super)
  end

end

Now, :profile => current_profile will be automerge to path/url parameters.

Example routing:

scope ":profile" do
  resources :comments
end

Just write:

comments_path

and if current_profile has set to_param to 'lucas':

/lucas/comments