Auth Module

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Auth Module (Developer Notes)

The Auth module extends functionality available from the [Authlogic|] (version 2.1.0) gem and included in the lib directory based on the [Authlogic OpenID add-on|].

Core Umlaut Files Added or Updated

Several core Umlaut files were updated in order to develop the Auth module.


The ApplicationController filters passwords and provides two methods for accessing the current user session and the current user.

  1. current_user_session (aliased as has_logged_in_user) - returns nil if no user session has been established
  2. current_user (aliased as logged_in_user) - returns either nil or the current logged in user

The application calls current_user_session as a before filter on every request.


The UserSessionsController manages the routing of user session requests and provides three methods.

  1. new - renders the login screen or redirects to external login screen
  2. validate - validates the user upon login
  3. destroy - processes logout


The UsersController manages the routing of user related requests and provides two methods.

  1. edit (also called from show) - renders the user preferences screen
  2. update - processes updates to user preferences (not yet implemented)


UserSessions extends Authlogic::Session::Base


User serializes user_attributes and adds acts_as_authentic functionality to leverage the Authlogic gem. Also sets to_param to username rather than id for prettier urls.


The default login screen, doesn't currently do anything.


The default user preferences screen. Users can update mobile phone numbers and the like (not yet implemented)


Added authlogic gem:

#require 'authlogic'
config.gem 'authlogic', :version => "= 2.1.0"


Added url routes:

  map.login "login", :controller => "user_sessions", :action => "new"
  map.logout "logout", :controller => "user_sessions", :action => "destroy"
  map.validate "validate", :controller => "user_sessions", :action => "validate"
  map.resources :user_sessions
  map.resources :users


Modified the user table to use with authlogic. Included column for mobile phone, user attributes and a refreshed_at date to track age of a particular record for better performance.


Make the user accessible from a particular user via the session_user method.

  # Returns the currently logged in user, if available, based on the user_credentials_id in the 
  # session from AuthLogic.  May want to make this more sophisticated and check user_credentials
  # against db.
  def session_user
    return User.find(session["user_credentials_id"]) unless session["user_credentials_id"].nil?

Auth Module

The following files makeup the Auth module to extend the functionality of Authlogic for our purposes.


ActsAsAuthentic extends the authlogic user model to ignore passwords, reset_persistence_token when the username changes, manage stale data (via refreshed_at date), and handle user attributes hash.


Session establishes the Auth module callback functions and can serve as a template for further localizations. Callback functions to be overridden locally as appropriate:

  1. before_login - called when a new user session is being established, before the actual login is called
  2. login_url - called if before_login isn't defined or returns false, convenience method for redirecting to an external login url
  3. after_login - called after login user has been validated, provides mechanism for authorization
  4. before_logout - called before current user session is destroyed
  5. after_logout - called after current user session is destroyed
  6. on_every_request - called on every request

It also has private methods validate_url (for sending to external logins) and session_user (for setting the session_user attributes).

Generating Local UmlautAuth Plugins

The following steps will generate a stub module for populating for local Auth needs (assumes authlogic version 2.1.0 is installed and user table is up to date).

  1.  script/generate UmlautAuth YourModuleName
  2.  put  your code in the generated stub methods in vendor/plugins/your_module_name/lib/your_module_name.rb
  3.  add the following to config/umlaut_config/environment.rb:
config.app_config.login_modules = [{:id => "your_module_name", :module => :YourModuleName, :default => true }] #default => true doesn't do anything yet

UmlautAuth Plugin Example

UmlautAuthOpenSSO was developed at NYU as an example of generating a plugin and populating the stub methods provided.

  • /vendor/plugins/umlaut_auth_open_sso