Change Foundation text direction in RTL languages

This way, when the language is written form right-to-left, elements
using Foundation mixins/classes will float to the opposite direction as
they do in left-to-right languages. The same will apply to text
alignment.

To offer full support for RTL languages, we need to change every single
reference to `float: left`, `float: right`, `text-align: left`,
`text-align: right`, and possible adjust other properties like `left`,
`margin-left`, `padding-left` or `border-left`. In the meantime, we at
least partially support these languages.

Replacing `float` with `flex` when possible would also improve RTL
support.

app/assets/stylesheets/application-rtl.scss

@@ -0,0 +1,3 @@
+$global-text-direction: rtl;
+
+@import "application";

app/helpers/application_helper.rb

@@ -6,6 +6,10 @@ module ApplicationHelper
     url_for(request.query_parameters.merge(query_parameters).merge(only_path: true))
   end
 
+  def rtl?
+    %i[ar fa he].include?(I18n.locale)
+  end
+
   def markdown(text)
     return text if text.blank?
 

app/views/layouts/_common_head.html.erb

@@ -2,7 +2,11 @@
 <meta name="viewport" content="width=device-width, initial-scale=1.0" />
 <meta http-equiv="X-UA-Compatible" content="IE=edge" />
 <title><%= content_for?(:title) ? yield(:title) : default_title %></title>
-<%= stylesheet_link_tag "application" %>
+<% if rtl? %>
+  <%= stylesheet_link_tag "application-rtl" %>
+<% else %>
+  <%= stylesheet_link_tag "application" %>
+<% end %>
 <%= javascript_include_tag "application", "data-turbolinks-track" => "reload" %>
 <%= csrf_meta_tags %>
 <%= favicon_link_tag "favicon.ico" %>

config/initializers/assets.rb

@@ -12,6 +12,7 @@ Rails.application.config.assets.version = "1.0"
 Rails.application.config.assets.precompile += %w[ckeditor/config.js]
 Rails.application.config.assets.precompile += %w[stat_graphs.js]
 Rails.application.config.assets.precompile += %w[dashboard_graphs.js]
+Rails.application.config.assets.precompile += %w[application-rtl.css]
 Rails.application.config.assets.precompile += %w[print.css]
 Rails.application.config.assets.precompile += %w[pdf_fonts.css]
 Rails.application.config.assets.precompile += %w[sdg/*.png]