title: Devise, Omniauth and Facebook integration session error
body: <p>I am new to Rails and am installing my first app that integrates Facebook sign in / sign up.  I followed Ryan Bates' RailsCast videos that were posted here: <a href="https://stackoverflow.com/a/4954443/1302333">https://stackoverflow.com/a/4954443/1302333</a>.</p>
  
  <p>I followed his tutorial for integrating Twitter and that works, but I'm having issues with Facebook.  When I visit <code>http://localhost:3000/auth/facebook</code> I receive this error:</p>
  
  <pre><code>NoMethodError in AuthenticationsController#create
  undefined method `serialize_into_session' for Symbol:Class
  </code></pre>
  
  <p>Here is the full trace:</p>
  
  <pre><code>devise (2.1.0) lib/devise/rails/warden_compat.rb:19:in `serialize'
  warden (1.1.1) lib/warden/session_serializer.rb:25:in `store'
  warden (1.1.1) lib/warden/proxy.rb:161:in `set_user'
  devise (2.1.0) lib/devise/controllers/helpers.rb:124:in `sign_in'
  devise (2.1.0) lib/devise/controllers/helpers.rb:236:in `sign_in_and_redirect'
  app/controllers/authentications_controller.rb:11:in `create'
  actionpack (3.2.6) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
  actionpack (3.2.6) lib/abstract_controller/base.rb:167:in `process_action'
  actionpack (3.2.6) lib/action_controller/metal/rendering.rb:10:in `process_action'
  actionpack (3.2.6) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
  activesupport (3.2.6) lib/active_support/callbacks.rb:414:in `_run__1508312784814672110__process_action__3616665370535505566__callbacks'
  activesupport (3.2.6) lib/active_support/callbacks.rb:405:in `__run_callback'
  activesupport (3.2.6) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
  activesupport (3.2.6) lib/active_support/callbacks.rb:81:in `run_callbacks'
  actionpack (3.2.6) lib/abstract_controller/callbacks.rb:17:in `process_action'
  actionpack (3.2.6) lib/action_controller/metal/rescue.rb:29:in `process_action'
  actionpack (3.2.6) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
  activesupport (3.2.6) lib/active_support/notifications.rb:123:in `block in instrument'
  activesupport (3.2.6) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
  activesupport (3.2.6) lib/active_support/notifications.rb:123:in `instrument'
  actionpack (3.2.6) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
  actionpack (3.2.6) lib/action_controller/metal/params_wrapper.rb:206:in `process_action'
  activerecord (3.2.6) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
  actionpack (3.2.6) lib/abstract_controller/base.rb:121:in `process'
  actionpack (3.2.6) lib/abstract_controller/rendering.rb:45:in `process'
  actionpack (3.2.6) lib/action_controller/metal.rb:203:in `dispatch'
  actionpack (3.2.6) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
  actionpack (3.2.6) lib/action_controller/metal.rb:246:in `block in action'
  actionpack (3.2.6) lib/action_dispatch/routing/route_set.rb:73:in `call'
  actionpack (3.2.6) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
  actionpack (3.2.6) lib/action_dispatch/routing/route_set.rb:36:in `call'
  journey (1.0.3) lib/journey/router.rb:68:in `block in call'
  journey (1.0.3) lib/journey/router.rb:56:in `each'
  journey (1.0.3) lib/journey/router.rb:56:in `call'
  actionpack (3.2.6) lib/action_dispatch/routing/route_set.rb:600:in `call'
  omniauth (1.1.0) lib/omniauth/strategy.rb:392:in `call_app!'
  omniauth (1.1.0) lib/omniauth/strategy.rb:354:in `callback_phase'
  omniauth-oauth2 (1.0.2) lib/omniauth/strategies/oauth2.rb:65:in `callback_phase'
  omniauth (1.1.0) lib/omniauth/strategy.rb:219:in `callback_call'
  omniauth (1.1.0) lib/omniauth/strategy.rb:175:in `call!'
  omniauth (1.1.0) lib/omniauth/strategy.rb:157:in `call'
  omniauth (1.1.0) lib/omniauth/strategy.rb:177:in `call!'
  omniauth (1.1.0) lib/omniauth/strategy.rb:157:in `call'
  omniauth (1.1.0) lib/omniauth/builder.rb:48:in `call'
  warden (1.1.1) lib/warden/manager.rb:35:in `block in call'
  warden (1.1.1) lib/warden/manager.rb:34:in `catch'
  warden (1.1.1) lib/warden/manager.rb:34:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
  rack (1.4.1) lib/rack/etag.rb:23:in `call'
  rack (1.4.1) lib/rack/conditionalget.rb:25:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/head.rb:14:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/flash.rb:242:in `call'
  rack (1.4.1) lib/rack/session/abstract/id.rb:205:in `context'
  rack (1.4.1) lib/rack/session/abstract/id.rb:200:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/cookies.rb:338:in `call'
  activerecord (3.2.6) lib/active_record/query_cache.rb:64:in `call'
  activerecord (3.2.6) lib/active_record/connection_adapters/abstract/connection_pool.rb:473:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
  activesupport (3.2.6) lib/active_support/callbacks.rb:405:in `_run__2824763875952710462__call__1302249347533121180__callbacks'
  activesupport (3.2.6) lib/active_support/callbacks.rb:405:in `__run_callback'
  activesupport (3.2.6) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
  activesupport (3.2.6) lib/active_support/callbacks.rb:81:in `run_callbacks'
  actionpack (3.2.6) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/reloader.rb:65:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
  railties (3.2.6) lib/rails/rack/logger.rb:26:in `call_app'
  railties (3.2.6) lib/rails/rack/logger.rb:16:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/request_id.rb:22:in `call'
  rack (1.4.1) lib/rack/methodoverride.rb:21:in `call'
  rack (1.4.1) lib/rack/runtime.rb:17:in `call'
  activesupport (3.2.6) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
  rack (1.4.1) lib/rack/lock.rb:15:in `call'
  actionpack (3.2.6) lib/action_dispatch/middleware/static.rb:62:in `call'
  railties (3.2.6) lib/rails/engine.rb:479:in `call'
  railties (3.2.6) lib/rails/application.rb:220:in `call'
  rack (1.4.1) lib/rack/content_length.rb:14:in `call'
  railties (3.2.6) lib/rails/rack/log_tailer.rb:17:in `call'
  rack (1.4.1) lib/rack/handler/webrick.rb:59:in `service'
  /Users/felixthea/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service'
  /Users/felixthea/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run'
  /Users/felixthea/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/webrick/server.rb:183:in `block in start_thread'
  </code></pre>
  
  <p>And the authentications_controller.rb file:</p>
  
  <pre><code>class AuthenticationsController &lt; ApplicationController
    def index
      @authentications = current_user.authentications if current_user
    end
  
    def create
      omniauth = request.env["omniauth.auth"]
      authentication = Authentication.find_by_provider_and_uid(omniauth['provider'], omniauth['uid'])
      if authentication
        flash[:notice] = "Signed in successfully."
        sign_in_and_redirect(:user, authentication.user)
      elsif current_user
        current_user.authentications.create!(:provider =&gt; omniauth['provider'], :uid =&gt; omniauth['uid'])
        flash[:notice] = "Authentication successful."
        redirect_to authentications_url
      else
        user = User.new
        user.apply_omniauth(omniauth)
        if user.save
          flash[:notice] = "Signed in successfully."
          sign_in_and_redirect(:user, user)
        else
          session[:omniauth] = omniauth.except('extra')
          redirect_to new_user_registration_url
        end
      end
    end
  
    def destroy
      @authentication = current_user.authentications.find(params[:id])
      @authentication.destroy
      redirect_to authentications_url, :notice =&gt; "Successfully destroyed authentication."
    end
  
  protected
  
  # This is necessary since Rails 3.0.4
  # See https://github.com/intridea/omniauth/issues/185
  # and http://www.arailsdemo.com/posts/44
  def handle_unverified_request
   true
  end
  
  end
  </code></pre>
  
  <p>Any help would be appreciated!</p>
  
  <p>Thanks
  Felix</p>