Enable RTL direction in emails.

app/helpers/application_helper.rb

@@ -32,7 +32,7 @@ module ApplicationHelper
   end
 
   def html_classes
-    "#{mobile_view? ? 'mobile-view' : 'desktop-view'} #{mobile_device? ? 'mobile-device' : 'not-mobile-device'} #{rtl_view? ? 'rtl' : ''}"
+    "#{mobile_view? ? 'mobile-view' : 'desktop-view'} #{mobile_device? ? 'mobile-device' : 'not-mobile-device'} #{RTL.html_class}"
   end
 
   def escape_unicode(javascript)
@@ -124,21 +124,6 @@ module ApplicationHelper
     MobileDetection.mobile_device?(request.user_agent)
   end
 
-  def rtl_view?
-     site_default_rtl? || current_user_rtl?
-  end
-
-  def current_user_rtl?
-    SiteSetting.allow_user_locale && current_user.try(:locale).in?(rtl_locales)
-  end
-
-  def site_default_rtl?
-    !SiteSetting.allow_user_locale && SiteSetting.default_locale.in?(rtl_locales)
-  end
-
-  def rtl_locales
-    %w(he ar)
-  end
 
   def customization_disabled?
     controller.class.name.split("::").first == "Admin" || session[:disable_customization]

app/mailers/user_notifications.rb

@@ -198,7 +198,7 @@ class UserNotifications < ActionMailer::Base
     html = UserNotificationRenderer.new(Rails.configuration.paths["app/views"]).render(
       template: 'email/notification',
       format: :html,
-      locals: { context_posts: context_posts, post: post, top: top ? PrettyText.cook(top).html_safe : nil }
+      locals: { context_posts: context_posts, post: post, top: top ? PrettyText.cook(top).html_safe : nil, classes: RTL.html_class }
     )
 
     template = "user_notifications.user_#{notification_type}"

app/models/rtl.rb

@@ -0,0 +1,23 @@
+class RTL
+
+  def self.enabled?
+    site_locale_rtl? || current_user_rtl?
+  end
+
+  def self.current_user_rtl?
+    SiteSetting.allow_user_locale && current_user.try(:locale).in?(rtl_locales)
+  end
+
+  def self.site_locale_rtl?
+    !SiteSetting.allow_user_locale && SiteSetting.default_locale.in?(rtl_locales)
+  end
+
+  def self.rtl_locales
+    %w(he ar)
+  end
+
+  def self.html_class
+    enabled? ? 'rtl' : ''
+  end
+
+end

app/views/email/notification.html.erb

@@ -1,4 +1,4 @@
-<div id='main'>
+<div id='main' class=<%= classes %>>
 
 <% if top.present? %>
   <div><%= top %></div>

lib/email/styles.rb

@@ -53,6 +53,7 @@ module Email
       style('.user-avatar', 'vertical-align:top;width:55px;')
       style('.user-avatar img', nil, width: '45', height: '45')
       style('hr', 'background-color: #ddd; height: 1px; border: 1px;')
+      style('.rtl', 'direction: rtl;')
       # we can do this but it does not look right
       # style('#main', 'font-family:"Helvetica Neue", Helvetica, Arial, sans-serif')
       style('td.body', 'padding-top:5px;', colspan: "2")