Authlogic root url based on authenticated state - ruby-on-rails

Question

I'd like to be able to set the root url in routes.rb based on the logged in/out state of Authlogic. Here is an example of what I need to do:
root :to => 'users#index', :constraints => lambda { |request| # ??? }
root :to => 'welcome#index'
get '/' => 'users#index', :as => 'user_root'
This would enable logged in users to go to users#index and logged out users to go to welcome#index without doing a redirect. I do know how to set a before_filter and redirect accordingly, but I'd rather not do that.
I know this is possible with Devise but I need to solve this for Authlogic. Similar question here without an answer.

Answer 1

You can create a custom route constraint pretty easily. Any object that responds to matches? can be handed to the :constraints route option. To check for Authlogic authentication, you would need to pull your Authlogic methods from your ApplicationController and put them somewhere else. I recommend using a concern for these anyways.
# app/concerns/authlogic_methods.rb
module AuthlogicHelpers
extend ActiveSupport::Concern
module InstanceMethods
private # All methods are private
def current_user_session
return #current_user_session if defined?(#current_user_session)
#current_user_session = UserSession.find
end
def current_user
return #current_user if defined?(#current_user)
#current_user = current_user_session && current_user_session.user
end
end
end
# app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
include AuthlogicHelpers
end
# config/initializers/route_constraints.rb
module RouteConstraints
class LoggedIn
include AuthlogicHelpers
def matches?(request)
current_user
end
end
end
# config/routes.rb
constraints RouteConstraints::LoggedIn.new do
root :to => 'dashboard#show'
end
Note that we're instantiating a new RouteConstraints::LoggedIn object. This is because the Authlogic methods current_user and current_user_session are defined as instance methods and create instance variables — if they aren't separated for each request, you won't be sure a user is actually logged in or another one was logged in before.
You might run into problems if Authlogic tries to access params directly. In this case, you will probably need to override the UserSession.new method to accept the request object as an argument and call request.params to get the params.

Answer 2

Authlogic already have the machinery native (tested against Rails 6.0 and Authlogic 6.0):
class AuthlogicSignedInConstraint
def matches?(request)
Authlogic::Session::Base.controller = Authlogic::ControllerAdapters::AbstractAdapter.new(request)
user_session = UserSession.find
user_session && user_session.user
end
end

Answer 3

Authlogic in recent versions require a controller object to be instantiated otherwise it can't find the session data necessary for loading a session.
In fact, contained under authlogic/controller_adapters/ are adapters for various controller implementations: Rails Controllers, Sinatra and Rack.
The interface is fairly simple, so I wrote an adapter to work with the ActionDispatch::Request that one has access to within a constraint.
This has been tested on Rails 4.2, Rails 5 should be similar.
class AuthlogicRequestAdapter
attr_reader :request
def initialize(request)
#request = request
end
def authenticate_with_http_basic
end
def cookies
request.cookies
end
def params
request.params
end
def session
_, session_hash = Rails.application.config.session_store.new(Rails.application, Rails.application.config.session_options).load_session(request.env)
session_hash
end
end
Example of use in Rails
Route Constraint
class UserRouteConstraint
def matches?(request)
Authlogic::Session::Base.controller = AuthlogicRequestAdapter.new(request)
user = UserSession.find
if user&.record.present?
true
else
false
end
end
end
routes.rb
MyRailsApp::Application.routes.draw do
# ... other routes
constraints(UserRouteContraint.new) do
root :to => 'users#index'
end
root :to => 'welcome#index'
get '/' => 'users#index', :as => 'user_root'
end