Rails flash message using Twitter Bootstrap 3

_flash_messages.html.erb

<% flash.each do |type, message| %>
  <div class="alert <%= alert_class_for(type) %> alert-dismissable fade in">
    <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
    <%= message %>
  </div>
<% end %>

application.html.erb

<%= render partial: "shared/flash_messages", flash: flash %>

application_helper.rb

def alert_class_for(flash_type)
  {
    :success => 'alert-success',
    :error => 'alert-danger',
    :alert => 'alert-warning',
    :notice => 'alert-info'
  }[flash_type.to_sym] || flash_type.to_s
end