Add instructions for pulling the user id out of session storage

docs/authentication.md

@@ -126,6 +126,37 @@ end
 ```
 {% endcode %}
 
+
+### Sorcery-based Authentication (user id is in session storage)
+
+If you're using [Sorcery](https://github.com/Sorcery/sorcery) for authentication, you'd need to pull the user id out of the session store.
+
+{% code title="app/channels/application\_cable/connection.rb" %}
+```ruby
+module ApplicationCable
+  class Connection < ActionCable::Connection::Base
+    identified_by :current_user
+
+    def connect
+      self.current_user = find_verified_user
+    end
+
+    protected
+
+    def find_verified_user
+      user_id = request.session.fetch("user_id", nil)
+
+      if verified_user = User.find_by(id: user_id)
+        verified_user
+      else
+        reject_unauthorized_connection
+      end
+    end
+  end
+end
+```
+{% endcode %}
+
 Now you're free to delegate current\_user. Be home by lunch:
 
 {% code title="app/reflexes/example\_reflex.rb" %}