Fix cache with Rails 5.

lib/rucaptcha.rb

@@ -25,11 +25,6 @@ module RuCaptcha
 
     def configure(&block)
       config.instance_exec(&block)
-
-      # enable cache if cache_limit less than 1
-      if config.cache_limit >= 1
-        RuCaptcha::Captcha.send(:include, RuCaptcha::Cache)
-      end
     end
   end
 end

lib/rucaptcha/cache.rb

@@ -3,30 +3,27 @@ require 'fileutils'
 module RuCaptcha
   # File Cache
   module Cache
-    extend ActiveSupport::Concern
-
-    included do
-      class << self
-        alias_method_chain :create, :cache
-        alias_method_chain :random_chars, :cache
+    def self.prepended(base)
+      class << base
+        prepend ClassMethods
       end
     end
 
     module ClassMethods
-      def create_with_cache(code)
-        cache.fetch(code) do
-          create_without_cache(code)
+      def create(code)
+        cache.fetch(code, expires_in: 1.days) do
+          super(code)
         end
       end
 
-      def random_chars_with_cache
+      def random_chars
         if cached_codes.length >= RuCaptcha.config.cache_limit
           return cached_codes.sample
-        else
-          code = random_chars_without_cache
-          cached_codes << code
-          return code
         end
+
+        code = super
+        cached_codes << code
+        code
       end
 
       def cache
@@ -35,7 +32,8 @@ module RuCaptcha
         cache_path = Rails.root.join('tmp', 'cache', 'rucaptcha')
         FileUtils.mkdir_p(cache_path) unless File.exist? cache_path
         @cache = ActiveSupport::Cache::FileStore.new(cache_path)
-        @cache.clear
+        # clear expired captcha cache files on Process restart
+        @cache.cleanup
         @cache
       end
 

lib/rucaptcha/captcha.rb

@@ -77,7 +77,7 @@ module RuCaptcha
           png_file_path
         else
           command.strip!
-          out, err, st = Open3.capture3(command)
+          out, err, _st = Open3.capture3(command)
           raise "RuCaptcha: #{err.strip}" if err.present?
           out
         end

lib/rucaptcha/engine.rb

@@ -1,5 +1,12 @@
 module RuCaptcha
   class Engine < ::Rails::Engine
     isolate_namespace RuCaptcha
+
+    initializer 'rucaptcha.prepend.cache' do
+      # enable cache if cache_limit less than 1
+      if RuCaptcha.config.cache_limit >= 1
+        RuCaptcha::Captcha.send(:prepend, RuCaptcha::Cache)
+      end
+    end
   end
 end

lib/rucaptcha/version.rb

@@ -1,3 +1,3 @@
 module RuCaptcha
-  VERSION = '0.4.5'
+  VERSION = '0.5.0'
 end