Improve the localization concern, moving to around_action

rails_docker.rb

@@ -65,7 +65,7 @@ def source_paths
   <<~EOT
 
     import 'translations/translations';
-    
+
     import 'initializers/';
     import 'screens/';
   EOT
@@ -175,14 +175,14 @@ def source_paths
   insert_into_file 'config/webpack/environment.js', after: "const { environment } = require('@rails/webpacker')\n" do
     <<~EOT
       const webpack = require('webpack');
-      
+
       const plugins = [
         new webpack.ProvidePlugin({
           // Translations
           I18n: 'i18n-js',
         })
       ]
-  
+
       environment.config.set('plugins', plugins);
     EOT
   end
@@ -195,4 +195,18 @@ def source_paths
 
     EOT
   end
+
+  # I18n configuration
+  # Remove the incorrect fallback configuration (was generated by Rails) - https://github.com/ruby-i18n/i18n/releases/tag/v1.1.0
+  gsub_file('config/environments/production.rb', 'config.i18n.fallbacks = true', '')
+
+  # Adding the correct fallback configuration along with default locale and available locales
+  environment do
+    <<~EOT
+      config.i18n.available_locales = ENV.fetch('AVAILABLE_LOCALES').split(', ')
+      config.i18n.default_locale = ENV.fetch('DEFAULT_LOCALE')
+      config.i18n.fallbacks = ENV.fetch('FALLBACK_LOCALES').split(', ')
+
+    EOT
+  end
 end

rails_docker/Dockerfile.tt

@@ -4,6 +4,9 @@ ARG RUBY_ENV=development
 ARG NODE_ENV=development
 ARG BUILD_ENV=development
 ARG ASSET_HOST=http://localhost
+ARG AVAILABLE_LOCALES
+ARG DEFAULT_LOCALE
+ARG FALLBACK_LOCALES
 
 # Define all the envs here
 ENV RACK_ENV=$RUBY_ENV \

rails_docker/docker-compose.yml.tt

@@ -25,6 +25,9 @@ services:
         - NODE_ENV=production
         - BUILD_ENV=production
         - ASSET_HOST=
+        - AVAILABLE_LOCALES
+        - DEFAULT_LOCALE
+        - FALLBACK_LOCALES
     image: ${DOCKER_IMAGE}:${BRANCH_TAG}
     container_name: <%= APP_NAME %>_web
     command: bin/start.sh

shared/app/controllers/concerns/localization.rb

@@ -2,12 +2,18 @@ module Localization
   extend ActiveSupport::Concern
 
   included do
-    before_action :set_locale
+    around_action :switch_locale
 
     protected
 
-    def set_locale
-      I18n.locale = params[:locale] || I18n.default_locale
+    def switch_locale(&action)
+      locale = extract_locale_from_param || I18n.default_locale
+
+      I18n.with_locale(locale, &action)
+    end
+
+    def extract_locale_from_param
+      I18n.locale_available?(params[:locale]) ? params[:locale].to_sym : nil
     end
 
     private

shared/config/application.yml.tt

@@ -6,6 +6,9 @@ default: &default
   MAILER_DEFAULT_HOST: "localhost"
   MAILER_DEFAULT_PORT: "3000"
   MAILER_SENDER: "Test <noreply@nimblehq.co>"
+  AVAILABLE_LOCALES: "en"
+  DEFAULT_LOCALE: "en"
+  FALLBACK_LOCALES: "en"
 
 development:
   <<: *default