Sessions for UpdatesController

lib/telegram/bot/railtie.rb

@@ -18,6 +18,7 @@ module Telegram
 
         ActiveSupport.on_load('telegram.bot.updates_controller') do
           self.logger = options.logger || Rails.logger
+          self.session_store = options.session_store || Rails.cache
         end
       end
 

lib/telegram/bot/updates_controller.rb

@@ -7,6 +7,10 @@ module Telegram
     class UpdatesController < AbstractController::Base
       abstract!
 
+      require 'telegram/bot/updates_controller/session'
+      require 'telegram/bot/updates_controller/log_subscriber'
+      require 'telegram/bot/updates_controller/instrumentation'
+
       include AbstractController::Callbacks
       # Redefine callbacks with default terminator.
       if ActiveSupport.gem_version >= Gem::Version.new('5')
@@ -19,10 +23,8 @@ module Telegram
       end
 
       include AbstractController::Translation
-
-      require 'telegram/bot/updates_controller/log_subscriber'
-      require 'telegram/bot/updates_controller/instrumentation'
       prepend Instrumentation
+      extend Session::ConfigMethods
 
       autoload :TypedUpdate, 'telegram/bot/updates_controller/typed_update'
 

lib/telegram/bot/updates_controller/session.rb

@@ -0,0 +1,72 @@
+require 'rack/session/abstract/id'
+require 'active_support/cache'
+
+module Telegram
+  module Bot
+    class UpdatesController
+      # Add functionality to store data between requests.
+      module Session
+        extend ActiveSupport::Concern
+
+        def process_action(*)
+          super
+        ensure
+          session.commit
+        end
+
+        protected
+
+        def session
+          @_session ||= SessionHash.new(self.class.session_store, session_key)
+        end
+
+        def session_key
+          "#{bot.username}:#{from ? "from:#{from['id']}" : "chat:#{chat['id']}"}"
+        end
+
+        # Rack::Session::Abstract::SessionHash is taken to provide lazy loading.
+        # All methods that access store are overriden to support
+        # ActiveSupport::Cache::Store stores.
+        class SessionHash < Rack::Session::Abstract::SessionHash
+          attr_reader :id
+
+          def initialize(store, id)
+            @store = store
+            @id = id
+          end
+
+          def destroy
+            clear
+            @store.delete(id)
+          end
+
+          def exists?
+            return @exists if defined?(@exists)
+            @data = {}
+            @exists = @store.exist? id
+          end
+
+          def load!
+            session = @store.read(id)
+            @data = session ? stringify_keys(session) : {}
+            @loaded = true
+          end
+
+          def commit
+            return unless loaded?
+            data = to_hash.delete_if { |_, v| v.nil? }
+            @store.write(id, data)
+          end
+        end
+
+        module ConfigMethods
+          delegate :session_store, to: :config
+
+          def session_store=(store)
+            config.session_store = ActiveSupport::Cache.lookup_store(store)
+          end
+        end
+      end
+    end
+  end
+end