Rails flash messages using Twitter Bootstrap

_flash_messages.html.erb

<% flash.each do |type, message| %>
  <div class="alert <%= bootstrap_class_for(type) %> fade in">
    <button class="close" data-dismiss="alert">×</button>
    <%= message %>
  </div>
<% end %>

application.html.erb

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

application_helper.rb

module ApplicationHelper
  def bootstrap_class_for(flash_type)
    case flash_type
    when "success" then "alert-success" # Green
    when "error"   then "alert-danger" # Red
    when "alert"   then "alert-warning" # Yellow
    when "notice"  then "alert-info" # Blue
    else flash_type.to_s
    end
  end
end