If you are using a plugin or library that calls url_for internally, you can force it to use a particular named route with the :use_route key. For instance, calling:
url_for(:controller => 'posts', :action => 'view', :id => post, :use_route => :special_post)
will have the same effect as:
Naturally, this is much more verbose if you’re calling it directly, but can be a lifesaver if url_for is being called inside another method (e.g. will_paginate).
Imagine the following case. You have two landing pages, one generic one, and an account specific one. The urls are as follows:
map.landing 'landing', :controller => 'landing', :action => 'index' map.account_landing 'accounts/:account_id/landing', :controller => 'landing', :action => 'index'
Now imagine you want a path to the landing page, using the most specific route possible. If you have an account_id, use it, if not, skip it.
You could do
url_for(:controller => 'landing', :action => 'index', :account_id => current_account)
If current_account is set you’ll get “/accounts/:account_id/landing” if not, you’ll get “/landing”. However, that just looks ugly.
Enter :use_route => nil.
landing_path(:account_id => nil) # => '/landing' landing_path(:account_id => 1) # => '/landing?account_id=1' landing_path(:account_id => nil, :use_route => nil) # => '/landing' landing_path(:account_id => 1, :use_route => nil) # => '/accounts/1/landing'
Setting :use_route to nil, is equivalent to the earlier #url_for example.