Initial routes and module setup.

app/controllers/devise/oauth_callbacks_controller.rb

@@ -0,0 +1,9 @@
+class Devise::OauthCallbacksController < ApplicationController
+  include Devise::Controllers::InternalHelpers
+
+  def twitter
+  end
+
+  def github
+  end
+end

lib/devise.rb

@@ -161,14 +161,38 @@ module Strategies
   mattr_accessor :navigational_formats
   @@navigational_formats = [:html]
 
+  # When set to true, signing out an user signs out all other scopes.
+  mattr_accessor :sign_out_all_scopes
+  @@sign_out_all_scopes = false
+
+  # Oauth providers
+  mattr_accessor :oauth_providers
+  @@oauth_providers = []
+
+  # PRIVATE CONFIGURATION
+
+  # Oauth configurations.
+  mattr_reader :oauth_configs
+  @@oauth_configs = {}
+
   # Private methods to interface with Warden.
   mattr_accessor :warden_config
   @@warden_config = nil
   @@warden_config_block = nil
 
-  # When set to true, signing out an user signs out all other scopes.
-  mattr_accessor :sign_out_all_scopes
-  @@sign_out_all_scopes = false
+  # Specify an oauth provider.
+  #
+  #   config.oauth :github, APP_ID, APP_SECRET,
+  #     :site              => 'https://github.com/',
+  #     :authorize_path    => '/login/oauth/authorize',
+  #     :access_token_path => '/login/oauth/access_token',
+  #     :scope             =>  %w(user public_repo)
+  #
+  def self.oauth(provider, *args)
+    @@oauth_providers << provider
+    @@oauth_providers.uniq!
+    @@oauth_configs[provider] = Devise::OAuth::Config.new(*args)
+  end
 
   def self.use_default_scope=(*)
     ActiveSupport::Deprecation.warn "config.use_default_scope is deprecated and removed from Devise. " <<
@@ -209,7 +233,6 @@ def self.add_mapping(resource, options)
   #   +model+      - String representing the load path to a custom *model* for this module (to autoload.)
   #   +controller+ - Symbol representing the name of an exisiting or custom *controller* for this module.
   #   +route+      - Symbol representing the named *route* helper for this module.
-  #   +flash+      - Symbol representing the *flash messages* used by this helper.
   #   +strategy+   - Symbol representing if this module got a custom *strategy*.
   #
   # All values, except :model, accept also a boolean and will have the same name as the given module
@@ -243,8 +266,8 @@ def self.add_module(module_name, options = {})
     end
 
     if options[:model]
-      model_path = (options[:model] == true ? "devise/models/#{module_name}" : options[:model])
-      Devise::Models.send(:autoload, module_name.to_s.camelize.to_sym, model_path)
+      path = (options[:model] == true ? "devise/models/#{module_name}" : options[:model])
+      Devise::Models.send(:autoload, module_name.to_s.camelize.to_sym, path)
     end
 
     Devise::Mapping.add_module module_name

lib/devise/models/oauthable.rb

@@ -0,0 +1,11 @@
+module Devise
+  module Models
+    module Oauthable
+      extend ActiveSupport::Concern
+
+      module ClassMethods
+        Devise::Models.config(self, :oauth_providers)
+      end
+    end
+  end
+end

lib/devise/modules.rb

@@ -8,7 +8,10 @@
     s.add_module :rememberable
   end
 
-  # Misc after   
+  # Other authentications
+  d.add_module :oauthable, :controller => :oauth_callbacks, :route => :oauth_callback
+
+  # Misc after
   d.add_module :recoverable,  :controller => :passwords,     :route => :password
   d.add_module :registerable, :controller => :registrations, :route => :registration
   d.add_module :validatable

lib/devise/rails/routes.rb

@@ -231,6 +231,11 @@ def devise_registration(mapping, controllers) #:nodoc:
                  :path_names => { :new => mapping.path_names[:sign_up] }, :controller => controllers[:registrations]
       end
 
+      def devise_oauth_callback(mapping, controllers) #:nodoc:
+        get "/oauth/:action/callback", :action => Regexp.union(mapping.to.oauth_providers.map(&:to_s)),
+          :to => controllers[:oauth_callbacks], :as => :outh_callback
+      end
+
       def with_devise_exclusive_scope(new_path, new_as) #:nodoc:
         old_as, old_path, old_module = @scope[:as], @scope[:path], @scope[:module]
         @scope[:as], @scope[:path], @scope[:module] = new_as, new_path, nil

test/rails_app/app/active_record/user.rb

@@ -1,7 +1,7 @@
 class User < ActiveRecord::Base
   devise :database_authenticatable, :confirmable, :lockable, :recoverable,
          :registerable, :rememberable, :timeoutable, :token_authenticatable,
-         :trackable, :validatable
+         :trackable, :validatable, :oauthable, :oauth_providers => [:github, :twitter]
 
   attr_accessible :username, :email, :password, :password_confirmation
 end

test/rails_app/app/mongoid/user.rb

@@ -6,5 +6,5 @@ class User
 
   devise :database_authenticatable, :confirmable, :lockable, :recoverable,
          :registerable, :rememberable, :timeoutable, :token_authenticatable,
-         :trackable, :validatable
+         :trackable, :validatable, :oauthable, :oauth_providers => [:github, :twitter]
 end

test/routes_test.rb

@@ -86,6 +86,15 @@ class DefaultRoutingTest < ActionController::TestCase
     assert_recognizes({:controller => 'devise/registrations', :action => 'destroy'}, {:path => 'users', :method => :delete})
   end
 
+  test 'map oauth callbacks' do
+    assert_recognizes({:controller => 'devise/oauth_callbacks', :action => 'twitter'}, {:path => 'users/oauth/twitter/callback', :method => :get})
+    assert_recognizes({:controller => 'devise/oauth_callbacks', :action => 'github'}, {:path => 'users/oauth/github/callback', :method => :get})
+
+    assert_raise ActionController::RoutingError do
+      assert_recognizes({:controller => 'devise/oauth_callbacks', :action => 'facebook'}, {:path => 'users/oauth/facebook/callback', :method => :get})
+    end
+  end
+
   protected
 
   def assert_named_route(result, name)