Alert message helpers for Rails

_flash_messages.html.erb

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

application_helper.rb

module ApplicationHelper

  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

end