From afd386e098c46691cd1766097c1c5f89f40b4eef Mon Sep 17 00:00:00 2001
From: Daniel Miranda <danielkza2@gmail.com>
Date: Mon, 23 Mar 2015 14:46:28 -0300
Subject: [PATCH] Implement language detection from browser information

---
 Gemfile                                   |  3 +++
 Gemfile.lock                              |  2 ++
 app/controllers/application_controller.rb |  9 +++++----
 spec/controllers/home_controller_spec.rb  | 27 +++++++++++++++++++++++++--
 4 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/Gemfile b/Gemfile
index 66456e7..583a468 100644
--- a/Gemfile
+++ b/Gemfile
@@ -63,6 +63,9 @@ gem 'exception_notification', '~> 4.0.1'
 # Google Analytics
 gem 'google-analytics-rails', '~> 0.0.6'
 
+# Browser language detection
+gem 'http_accept_language'
+
 group :test do
   # Easier test writing
   gem "shoulda-matchers", '~> 2.8.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 979db6b..9c2f107 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -138,6 +138,7 @@ GEM
       activesupport (>= 4.1.0)
     google-analytics-rails (0.0.6)
     hike (1.2.3)
+    http_accept_language (2.0.5)
     i18n (0.7.0)
     jbuilder (2.2.12)
       activesupport (>= 3.0.0, < 5)
@@ -318,6 +319,7 @@ DEPENDENCIES
   exception_notification (~> 4.0.1)
   factory_girl_rails (~> 4.5.0)
   google-analytics-rails (~> 0.0.6)
+  http_accept_language
   jbuilder (~> 2.2.2)
   jquery-rails
   jquery-ui-rails (~> 5.0.0)
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 4160e67..d53225a 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -1,3 +1,5 @@
+require 'http_accept_language'
+
 class ApplicationController < ActionController::Base
   # Prevent CSRF attacks by raising an exception.
   # For APIs, you may want to use :null_session instead.
@@ -17,10 +19,9 @@ class ApplicationController < ActionController::Base
   end
 
   def set_locale
-    if (params[:locale])
-      I18n.locale = params[:locale]
-    else
-      I18n.locale = I18n.default_locale
+    compatible_locale = http_accept_language.compatible_language_from(I18n.available_locales)
+    unless compatible_locale.nil?
+      I18n.locale = compatible_locale
     end
   end
 end
diff --git a/spec/controllers/home_controller_spec.rb b/spec/controllers/home_controller_spec.rb
index 46904cb..1447db4 100644
--- a/spec/controllers/home_controller_spec.rb
+++ b/spec/controllers/home_controller_spec.rb
@@ -5,11 +5,34 @@ describe HomeController, :type => :controller do
     context '#index' do
       before :each do
         Project.expects(:latest).with(5).returns([])
+      end
 
-        get :index
+      describe 'Rendering' do
+        before :each do
+          get :index
+        end
+        it {is_expected.to render_template(:index)}
       end
 
-      it {is_expected.to render_template(:index)}
+      describe 'Language auto-detection' do
+        it 'should automatically use the language specified in the request headers' do
+          request.env['HTTP_ACCEPT_LANGUAGE'] = 'pt-BR'
+          get :index
+          expect(I18n.locale).to eq(:pt)
+        end
+
+        it 'should use a different region if still the best match' do
+          request.env['HTTP_ACCEPT_LANGUAGE'] = 'en-GB'
+          get :index
+          expect(I18n.locale).to eq(:en)
+        end
+
+        it 'should use the default language if no available language matches the requested one' do
+          request.env['HTTP_ACCEPT_LANGUAGE'] = 'de'
+          get :index
+          expect(I18n.locale).to eq(:en)
+        end
+      end
     end
   end
 end
--
libgit2 0.21.2