Add language detection (#1772)

* Add language detection via WhatLanguage and (de)serialization of it through Atom

* Fix default language in ProcessFeedService

* Re-add newline before 'react-rails' Gem to fix groupings

Fixes Code Climate issue

2 files changed, 10 insertions, 0 deletions

diff --git a/app/services/post_status_service.rb b/app/services/post_status_service.rb
index 221aa42a3..d8202bea8 100644
--- a/app/services/post_status_service.rb
+++ b/app/services/post_status_service.rb
@@ -19,6 +19,7 @@ class PostStatusService < BaseService
                                       sensitive: options[:sensitive],
                                       spoiler_text: options[:spoiler_text] || '',
                                       visibility: options[:visibility],
+                                      language: detect_language(text),
                                       application: options[:application])
 
     attach_media(status, media)
@@ -51,6 +52,10 @@ class PostStatusService < BaseService
     media.update(status_id: status.id)
   end
 
+  def detect_language(text)
+    WhatLanguage.new(:all).language_iso(text)
+  end
+
   def process_mentions_service
     @process_mentions_service ||= ProcessMentionsService.new
   end
diff --git a/app/services/process_feed_service.rb b/app/services/process_feed_service.rb
index 64a531e74..98d92f630 100644
--- a/app/services/process_feed_service.rb
+++ b/app/services/process_feed_service.rb
@@ -119,6 +119,7 @@ class ProcessFeedService < BaseService
         spoiler_text: content_warning(entry),
         created_at: published(entry),
         reply: thread?(entry),
+        language: content_language(entry),
         visibility: visibility_scope(entry)
       )
 
@@ -238,6 +239,10 @@ class ProcessFeedService < BaseService
       xml.at_xpath('./xmlns:content', xmlns: TagManager::XMLNS).content
     end
 
+    def content_language(xml = @xml)
+      xml.at_xpath('./xmlns:content', xmlns: TagManager::XMLNS)['xml:lang']&.presence || 'en'
+    end
+
     def content_warning(xml = @xml)
       xml.at_xpath('./xmlns:summary', xmlns: TagManager::XMLNS)&.content || ''
     end