Translate Rails flash key to metronic theme alert class

app_views_application__flashes.html.erb

<% #  Metronic theme alert classes can be used to style Rails 4 flash messages, for example like this. Render this partial from a page layout or page body. %>

<% if flash.any? %>
  <div class="alerts">
    <% user_facing_flashes.each do |key, value| -%>
      <% # translate flash key to metronic alert class %>
      <% # http://www.keenthemes.com/preview/metronic/theme/admin_1/ui_alerts_api.html %>
      <% alert_class = {'alert' => 'alert-warning', 'notice' => 'alert-info'}[key] %>
      <div class="alert <%= alert_class %>"><%= value %></div>
    <% end -%>
  </div>
<% end %>