Relative paths

app/assets/javascripts/components/transaction_form.jsx.coffee

@@ -184,7 +184,7 @@ Step = React.createFactory React.createClass
 
     div id: 'transaction-form',
       h3 null, 'Transfer some money'
-      form ref: 'form', action: '/transactions', acceptCharset: 'UTF-8', method: 'post',
+      form ref: 'form', action: "#{@window.base_url}/transactions", acceptCharset: 'UTF-8', method: 'post',
         Step step: 1, title: 'What do you want to do?',
           Action giving: giving, setAction: @setAction
         if step >= 2

app/views/layouts/application.html.haml

@@ -7,6 +7,8 @@
     = stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track' => true
     = javascript_include_tag 'application', 'data-turbolinks-track' => true
     = csrf_meta_tags
+    :javascript
+      window.base_url = "#{Rails.application.config.relative_url_root}"
   %body
     .pure-g
       = render 'menu' if current_user

config/environments/production.rb

@@ -76,4 +76,5 @@ Rails.application.configure do
 
   # Do not dump schema after migrations.
   config.active_record.dump_schema_after_migration = false
+  config.relative_url_root = "/tab"
 end