detect users preferred language

Gemfile

@@ -56,6 +56,9 @@ gem 'bigbluebutton-api-ruby'
 gem 'bootstrap', '~> 4.1.1'
 gem 'tabler-rubygem'
 
+# For detecting the users preferred language.
+gem 'http_accept_language'
+
 # Use Capistrano for deployment
 # gem 'capistrano-rails', group: :development
 

Gemfile.lock

@@ -83,6 +83,7 @@ GEM
     globalid (0.4.1)
       activesupport (>= 4.2.0)
     hashie (3.5.7)
+    http_accept_language (2.1.1)
     i18n (1.0.1)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.1)
@@ -274,6 +275,7 @@ DEPENDENCIES
   dotenv-rails
   factory_bot_rails
   faker
+  http_accept_language
   jbuilder (~> 2.5)
   jquery-rails
   listen (~> 3.0.5)

app/controllers/application_controller.rb

@@ -6,16 +6,22 @@ class ApplicationController < ActionController::Base
   include SessionsHelper
 
   before_action :migration_error?
+  before_action :set_locale
+
+  protect_from_forgery with: :exception
+
+  MEETING_NAME_LIMIT = 90
+  USER_NAME_LIMIT = 30
 
   # Show an information page when migration fails and there is a version error.
   def migration_error?
     render :migration_error unless ENV["DB_MIGRATE_FAILED"].blank?
   end
 
-  protect_from_forgery with: :exception
-
-  MEETING_NAME_LIMIT = 90
-  USER_NAME_LIMIT = 30
+  # Sets the appropriate locale.
+  def set_locale
+    I18n.locale = http_accept_language.language_region_compatible_from(I18n.available_locales)
+  end
 
   def meeting_name_limit
     MEETING_NAME_LIMIT

config/application.rb

@@ -17,9 +17,16 @@ module Greenlight
     # Use custom error routes.
     config.exceptions_app = routes
 
+    # Configure I18n localization.
+    config.i18n.available_locales = %w(en)
+    config.i18n.default_locale = "en"
+
+    # Check if a loadbalancer is configured.
     config.loadbalanced_configuration = ENV["LOADBALANCER_ENDPOINT"].present? && ENV["LOADBALANCER_SECRET"].present?
+
     # The default callback url that bn launcher will redirect to
     config.gl_callback_url = ENV["GL_CALLBACK_URL"]
+
     # Setup BigBlueButton configuration.
     if config.loadbalanced_configuration
       # Fetch credentials from a loadbalancer based on provider.