Locale can be selected at signup or changed in profile form

app/controllers/application_controller.rb

@@ -3,16 +3,20 @@ class ApplicationController < ActionController::Base
   rescue_from Pundit::NotAuthorizedError, with: :user_not_authorized
 
   before_action :configure_devise_parameters, if: :devise_controller?
-
+  before_action :set_locale
   protected
 
   def configure_devise_parameters
-    devise_parameter_sanitizer.permit(:sign_up, keys: [:tos_accepted])
-    devise_parameter_sanitizer.permit(:account_update, keys: [:notifications_enabled])
+    devise_parameter_sanitizer.permit(:sign_up, keys: [:tos_accepted, :locale])
+    devise_parameter_sanitizer.permit(:account_update, keys: [:notifications_enabled, :locale])
   end
 
   def user_not_authorized
     flash[:alert] = I18n.t("user_not_authorized", scope: :flashes)
     redirect_to(request.referrer || root_path)
   end
+
+  def set_locale
+    I18n.locale = current_user.try(:locale) || I18n.default_locale
+  end
 end

app/models/user.rb

@@ -12,6 +12,7 @@
 #  encrypted_password     :string(255)      default(""), not null
 #  last_sign_in_at        :datetime
 #  last_sign_in_ip        :string(255)
+#  locale                 :string(5)        default("en"), not null
 #  notifications_enabled  :boolean          default(TRUE), not null
 #  remember_created_at    :datetime
 #  reset_password_sent_at :datetime
@@ -37,6 +38,7 @@ class User < ApplicationRecord
 
   has_many :checks
   validates :tos_accepted, acceptance: true
+  validates :locale, inclusion: { in: I18n.available_locales }
 
   scope :notifications_disabled, -> { where(notifications_enabled: false) }
 

app/views/devise/registrations/edit.html.erb

@@ -24,6 +24,8 @@
       <%= f.input :password_confirmation, autocomplete: "off" %>
     </div>
 
+    <%= f.input :locale, label: t('.locale'), collection: I18n.available_locales, selected: resource.locale %>
+
     <%= f.input :notifications_enabled %>
 
     <%= f.button :submit, t('.update'), class: "btn-primary" %>

app/views/devise/registrations/new.html.erb

@@ -9,6 +9,8 @@
 
     <%= f.input :password_confirmation, autocomplete: "off" %>
 
+    <%= f.input :locale, label: t('.locale'), collection: I18n.available_locales, selected: I18n.default_locale %>
+
     <%= f.input :tos_accepted, label: t('.tos_acceptance_html') %>
 
     <%= f.button :submit, t('.sign_up'), class: "btn-primary" %>

db/migrate/20180613055303_add_locale_to_users.rb

@@ -0,0 +1,5 @@
+class AddLocaleToUsers < ActiveRecord::Migration[5.2]
+  def change
+    add_column :users, :locale, :string, null: false, default: "en", limit: 5
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2018_06_02_154319) do
+ActiveRecord::Schema.define(version: 2018_06_13_055303) do
 
   create_table "check_logs", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
     t.bigint "check_id"
@@ -72,6 +72,7 @@ ActiveRecord::Schema.define(version: 2018_06_02_154319) do
     t.datetime "updated_at", null: false
     t.boolean "tos_accepted", default: false, null: false
     t.boolean "notifications_enabled", default: true, null: false
+    t.string "locale", limit: 5, default: "en", null: false
     t.index ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true
     t.index ["email"], name: "index_users_on_email", unique: true
     t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true

test/factories/users.rb

@@ -12,6 +12,7 @@
 #  encrypted_password     :string(255)      default(""), not null
 #  last_sign_in_at        :datetime
 #  last_sign_in_ip        :string(255)
+#  locale                 :string(5)        default("en"), not null
 #  notifications_enabled  :boolean          default(TRUE), not null
 #  remember_created_at    :datetime
 #  reset_password_sent_at :datetime
@@ -28,6 +29,7 @@
 #  index_users_on_email                 (email) UNIQUE
 #  index_users_on_reset_password_token  (reset_password_token) UNIQUE
 #
+
 require "securerandom"
 
 FactoryBot.define do
@@ -36,6 +38,7 @@ FactoryBot.define do
     password "password"
     confirmed_at Time.new(2018, 4, 1, 12, 0, 0, "+02:00")
     notifications_enabled true
+    locale "en"
     tos_accepted true
   end
 end

test/models/user_test.rb

@@ -12,6 +12,7 @@
 #  encrypted_password     :string(255)      default(""), not null
 #  last_sign_in_at        :datetime
 #  last_sign_in_ip        :string(255)
+#  locale                 :string(5)        default("en"), not null
 #  notifications_enabled  :boolean          default(TRUE), not null
 #  remember_created_at    :datetime
 #  reset_password_sent_at :datetime