Symfony Flash Message

Controller.php

<?php
$this->get('session')->getFlashBag()->add(
    'notice',
    array(
        'type' => 'info',
        'class' => 'alert alert-info fade in',
        'title' => 'Message flash :',
        'dismissible' => 'alert-dismissible',
        'buttonClose' => '<button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>',
        'message' => 'La page de contact n\'est pas encore disponible, merci de revenir plus tard.'
    )
);
?>

html.twig

{% for flashMessage in app.session.flashbag.get('notice') %}
    <div class="{{ (flashMessage.dismissible is defined) ? flashMessage.class : 'alert' }} {{ (flashMessage.dismissible is defined) ? flashMessage.dismissible : '' }}" role="alert">
      {{ (flashMessage.buttonClose is defined) ? flashMessage.buttonClose|raw : '' }}
      <strong>{{ flashMessage.title }}</strong> {{ flashMessage.message }}
    </div>
{% endfor %}