webservice/application/views/helpers/ProfileLink.php

<?php

class Zend_View_Helper_ProfileLink extends Zend_View_Helper_Abstract
{
    public function profileLink()
    {
        $auth = Zend_Auth::getInstance();
        if ($auth->hasIdentity()) {
            $username = $auth->getIdentity()->username;
            $logoutUrl = $this->view->url(array(
                'controller' => 'user',
                'action' => 'logout'
            ), null, true);
            return '<a href="'.$logoutUrl.'" title="Se déconnecter" class="navbar-link">Déconnexion : ' . $username .  '</a>';
        }
    }
}