Use the null object pattern for current_user when not logged in

2 files changed, 17 insertions, 2 deletions

diff --git a/app/helpers/sessions_helper.rb b/app/helpers/sessions_helper.rb
index 54e4b0d..89e5ef3 100644
--- a/app/helpers/sessions_helper.rb
+++ b/app/helpers/sessions_helper.rb
@@ -18,7 +18,7 @@ module SessionsHelper
 	def current_user
 		@token ||= Session.hash_token(cookies[:remember_token])
 		@session ||= Session.find_by(token: @token)
-		@current_user ||= (@session.nil? ? nil : @session.user)
+		@current_user ||= (@session.nil? ? NilUser.new : @session.user)
 	end
 
 	# checks if someone is currently signed in
@@ -30,7 +30,7 @@ module SessionsHelper
 		if signed_in?
 			@session.destroy
 		end
-		@current_user = nil
+		@current_user = NilUser.new
 		cookies.delete(:remember_token)
 	end
 
diff --git a/app/models/user.rb b/app/models/user.rb
index 277d885..016c155 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -91,3 +91,18 @@ class User < ActiveRecord::Base
 
 	validates :password, length: { minimum: 6 }
 end
+class NilUser
+	def nil?
+		return true
+	end
+	def can?(action)
+		return false
+	end
+	def method_missing(name, *args)
+		# Throw an error if User doesn't have this method
+		super unless User.new.respond_to?(name)
+		# User has this method -- return a blank value
+		# 'false' if the method ends with '?'; 'nil' otherwise.
+		name.ends_with?('?') ? false : nil
+	end
+end