根据用户是否已登录而更改root用户，而无需在Ruby on Rails上进行Devise

Question

I want to use another root for my application when a user is already logged in but I don't know how to do it without Devise, we implemented all of the authentication's logic from scratch. We're using Rails 4.

Answer 1

In Devise there is a authenticated routes helper which lets you create routes which are only accessible to an authenticated user:

unauthenticated do
  root 'pages#home'
end

authenticated do
  root 'dashboard#index'
  resources :things
end

This is possible due to the fact that Warden actually does most of the heavy lifting when it comes to authentication and Warden lives on the rack layer.

Lets say you have a bare bones system on top of Warden. This is how you would create something similiar:

module ActionDispatch::Routing
  class Mapper
    def authenticated(&block)
      block.call if env['warden'].authenticated?  
    end

    def unauthenticated(&block)
      block.call if env['warden'].unauthenticated?  
    end
  end
end

You can replace env['warden'].unauthenticated? with whatever you have in your home rolled authentication system - but note that it has to work as Rack middleware. If your authentication system is some junk shoved into ApplicationController or a helper its not going work as that is far too late in the request cycle.