current website language is calculated model-side

app/controllers/admin/communication/websites/application_controller.rb

@@ -7,11 +7,7 @@ class Admin::Communication::Websites::ApplicationController < Admin::Communicati
   protected
 
   def current_website_language
-    @current_website_language ||= begin
-      language = @website.languages.find_by(iso_code: params[:lang])
-      language ||= @website.default_language
-      language
-    end
+    @current_website_language ||= @website.best_language_for(params[:lang])
   end
   helper_method :current_website_language
 

app/models/communication/website.rb

@@ -98,6 +98,12 @@ class Communication::Website < ApplicationRecord
     dependencies
   end
 
+  def best_language_for(iso_code)
+    # We look for the language by the ISO code in the websites languages.
+    # If not found, we fallback to the default language.
+    languages.find_by(iso_code: iso_code) || default_language
+  end
+
   protected
 
   def languages_must_include_default_language