add language dropdown

Gemfile.lock

@@ -191,6 +191,8 @@ GEM
     net-smtp (0.3.3)
       net-protocol
     nio4r (2.5.9)
+    nokogiri (1.15.4-x86_64-darwin)
+      racc (~> 1.4)
     nokogiri (1.15.4-x86_64-linux)
       racc (~> 1.4)
     orm_adapter (0.5.0)
@@ -340,6 +342,7 @@ GEM
       actionpack (>= 5.2)
       activesupport (>= 5.2)
       sprockets (>= 3.0.0)
+    sqlite3 (1.6.4-x86_64-darwin)
     sqlite3 (1.6.4-x86_64-linux)
     stimulus-rails (1.2.2)
       railties (>= 6.0.0)
@@ -375,6 +378,7 @@ GEM
     zeitwerk (2.6.11)
 
 PLATFORMS
+  x86_64-darwin-22
   x86_64-linux
 
 DEPENDENCIES

app/controllers/application_controller.rb

@@ -1,14 +1,32 @@
 class ApplicationController < ActionController::Base
   before_action :configure_permitted_parameters, if: :devise_controller?
+  before_action :set_current_locale
+  helper_method :current_locale
 
   rescue_from ActionPolicy::Unauthorized do |_e|
     redirect_to root_path
   end
 
+  def set_current_locale
+    Current.locale = extract_locale_from_user || extract_locale_from_session || I18n.default_locale
+  end
+
   private
 
   def configure_permitted_parameters
     devise_parameter_sanitizer.permit(:sign_up, keys: %i[name avatar])
     devise_parameter_sanitizer.permit(:account_update, keys: %i[name avatar])
   end
+
+  def current_locale
+    Current.locale
+  end
+
+  def extract_locale_from_user
+    current_user&.locale if defined?(current_user) && current_user&.locale
+  end
+
+  def extract_locale_from_session
+    session[:locale]
+  end
 end

app/controllers/pages_controller.rb

@@ -1,3 +1,33 @@
 class PagesController < ApplicationController
   def welcome; end
+
+  def switch_locale
+    Current.locale = locale
+    I18n.locale = Current.locale
+    store_locale
+
+    redirect_back(fallback_location: root_path)
+  end
+
+  private
+
+  def params_locale
+    params[:locale].to_sym
+  end
+
+  def default_locale
+    @default_locale ||= current_user&.locale || I18n.default_locale
+  end
+
+  def locale
+    I18n.available_locales.include?(params_locale) ? params_locale : default_locale
+  end
+
+  def store_locale
+    if user_signed_in?
+      current_user.update(locale: I18n.locale)
+    else
+      session[:locale] = I18n.locale
+    end
+  end
 end

app/helpers/navbar_helper.rb

@@ -0,0 +1,11 @@
+module NavbarHelper
+  def selected_language_icon
+    Rails.cache.fetch("selected_language_name/#{current_locale}", expires_in: 1.day) do
+      image_tag "icons/#{current_locale}.svg", size: "23", class: "rounded-2", title: t("navbar.language")
+    end
+  end
+
+  def next_locale
+    I18n.locale == :ru ? :en : :ru
+  end
+end

app/models/current.rb

@@ -0,0 +1,3 @@
+class Current < ActiveSupport::CurrentAttributes
+  thread_mattr_accessor :locale
+end

app/models/user.rb

@@ -30,10 +30,29 @@ class User < ApplicationRecord
                                     foreign_key: :recipient_id, dependent: :destroy, inverse_of: :recipient
 
   enum :role, %i[applicant company moderator admin]
+  # Нежелательное использование колбека в модели, но это врменное решение до определения логики devise
+  before_validation :set_name, if: -> { name.blank? }, on: :create
 
   validates :locale, presence: true
 
   def owner?(vacancy)
     id == vacancy.user_id
   end
+
+  def display_name
+    name || name_from_email
+  end
+
+  private
+
+  def set_name
+    self.name = name_from_email
+  end
+
+  def name_from_email
+    name_part = email.split("@").first
+    return name_part if [".", "_", "-"].include?(name_part[1])
+
+    name_part.humanize
+  end
 end

app/views/layouts/_header.html.slim

@@ -13,10 +13,18 @@ nav.navbar.navbar-expand-lg.bg-body-tertiary
         - if user_signed_in?
           li.nav-item
             = link_to "My Vacancies", my_vacancies_vacancies_path, class: "nav-link fs-4 text-black"
-      ul.navbar-nav.ms-3
+      ul.navbar-nav.ms-3.gap-1
+        li.nav-item[data-turbo="false"]
+          = link_to switch_locale_path(locale: next_locale), class: "btn btn-outline-primary border-0 me-2" do
+            = selected_language_icon
+
         li.nav-item.dropdown
           - if user_signed_in?
-            = link_to current_user.name? ? current_user.name : current_user.email, "#", class: "dropdown-toggle btn btn-outline-primary", id: "navbarDropdown", role: "button", "data-bs-toggle" => "dropdown", "aria-expanded" => "false"
+            = link_to "javascript:void(0);", 
+            class: "dropdown-toggle btn btn-outline-primary", id: "navbarDropdown", role: "button", 
+            "data-bs-toggle" => "dropdown", "aria-expanded" => "false" do
+              span.ms-1.me-2 
+                = current_user.display_name
             .dropdown-menu[aria-labelledby="navbarDropdown"]
               = link_to "Edit profile", edit_user_registration_path, class: "dropdown-item"
               .li.hr.dropdown-divider

config/locales/en.yml

@@ -31,3 +31,5 @@
 
 en:
   hello: "Hello world"
+  navbar:
+    language: Change language

config/locales/ru.yml

@@ -269,3 +269,6 @@ ru:
       long: "%d %B %Y, %H:%M"
       short: "%d %b, %H:%M"
     pm: вечера
+  navbar:
+    language: Смена языка
+

config/routes.rb

@@ -6,4 +6,6 @@
   resources :vacancies do
     get :my_vacancies, on: :collection
   end
+
+  get "/switch_locale/:locale", to: "pages#switch_locale", as: :switch_locale
 end

spec/requests/pages_controller_spec.rb

@@ -0,0 +1,72 @@
+require "rails_helper"
+
+describe PagesController, type: :request do
+  describe "GET /welcome" do
+    it "returns http status success" do
+      get root_url
+      expect(response).to have_http_status(:success)
+    end
+  end
+
+  describe "GET #switch_locale" do
+    let(:user) { create(:user) }
+
+    context "when user is signed in" do
+      before { sign_in user }
+
+      it "changes the I18n locale" do
+        get switch_locale_path(locale: "ru")
+        expect(I18n.locale).to eq(:ru)
+      end
+
+      it "changes the user locale" do
+        get switch_locale_path(locale: "ru")
+        expect(user.reload.locale).to eq("ru")
+      end
+
+      it "clears the session locale" do
+        get switch_locale_path(locale: "ru")
+        expect(session[:locale]).to be_nil
+      end
+
+      it "redirects back" do
+        get switch_locale_path(locale: "ru")
+        expect(response).to redirect_to(root_path)
+      end
+    end
+
+    context "when user is not signed in" do
+      it "changes the I18n locale" do
+        get switch_locale_path(locale: "ru")
+        expect(I18n.locale).to eq(:ru)
+      end
+
+      it "changes the session locale" do
+        get switch_locale_path(locale: "ru")
+        expect(session[:locale]).to eq(:ru)
+      end
+
+      it "redirects back" do
+        get switch_locale_path(locale: "ru")
+        expect(response).to redirect_to(root_path)
+      end
+    end
+
+    context "when the requested locale is not available" do
+      it "falls back to the default I18n locale" do
+        get switch_locale_path(locale: "invalid_locale")
+        expect(I18n.locale).to eq(:en)
+      end
+
+      it "falls back to the default session locale" do
+        get switch_locale_path(locale: "invalid_locale")
+        expect(session[:locale]).to eq(:en)
+      end
+
+      it "redirects back" do
+        get switch_locale_path(locale: "invalid_locale")
+        expect(response).to redirect_to(root_path)
+      end
+    end
+  end
+end