Delay loading of Active Record (#244)

Referencing `ActiveRecord::Base` as soon as the gem is required cause
Active Record being loaded earlier than it should and some Rails
configurations not to take effect.

Ref: rails/rails#49827
Ref: mastodon/mastodon#28609

cc @ClearlyClaire @mjankowski

Co-authored-by: Jean Boussier <[email protected]>

lib/rails-settings-cached.rb

@@ -9,14 +9,21 @@
 require_relative "rails-settings/fields/integer"
 require_relative "rails-settings/fields/string"
 
-require_relative "rails-settings/base"
 require_relative "rails-settings/configuration"
 require_relative "rails-settings/request_cache"
 require_relative "rails-settings/middleware"
 require_relative "rails-settings/railtie"
 require_relative "rails-settings/version"
 
 module RailsSettings
+  class ProtectedKeyError < RuntimeError
+    def initialize(key)
+      super("Can't use #{key} as setting key.")
+    end
+  end
+
+  autoload :Base, "rails-settings/base"
+
   module Fields
   end
 end

lib/rails-settings/base.rb

@@ -1,16 +1,12 @@
 # frozen_string_literal: true
 
 module RailsSettings
-  class ProtectedKeyError < RuntimeError
-    def initialize(key)
-      super("Can't use #{key} as setting key.")
-    end
-  end
-
   class Base < ActiveRecord::Base
     PROTECTED_KEYS = %w[var value]
     self.table_name = table_name_prefix + "settings"
 
+    after_commit :clear_cache, on: %i[create update destroy]
+
     # get the value field, YAML decoded
     def value
       # rubocop:disable Security/YAMLLoad

lib/rails-settings/railtie.rb

@@ -2,10 +2,6 @@
 
 module RailsSettings
   class Railtie < Rails::Railtie
-    initializer "rails_settings.active_record.initialization" do
-      RailsSettings::Base.after_commit :clear_cache, on: %i[create update destroy]
-    end
-
     initializer "rails_settings.configure_rails_initialization" do |app|
       app.middleware.use RailsSettings::Middleware
     end