Simple way to handle Bootstrap flash messages when using AJAX and the twitter-bootstrap-rails gem.

ajax.js.erb

// The below must be included somewhere in in .js.erb file.
...
$('#bootstrap-flash').html("<%= j (bootstrap_flash) %>");
...

application.html.erb

Before:

...
<div class="col-lg-12">=
  <%= bootstrap_flash %>
  <%= yield %>
</div>
...

After:
...
<div class="col-lg-12">
  <div id="bootstrap-flash">
    <%= bootstrap_flash %>
  </div>
  <%= yield %>
</div>
...

Just to add, in the controller action (e.g. destroy) for an address model, you need to add ".now" after flash so that the notification does not repair when you refresh the page. See below:

def destroy
@address = Address.destroy(params[:id])
respond_to do |wants|
wants.html { redirect_to addresses_path }
wants.js { flash.now[:danger] = "Address deleted." }
end
end