app/templates/client/directives(auth)/nav-bar/nav-bar.html
<nav>
<ul>
<li>
<a href="/">home</a>
</li>
<li ng-if="!Auth.isLogged()">
<a href="/signup">signup</a>
</li>
<li ng-if="!Auth.isLogged()">
<a href="/login">login</a>
</li>
<li ng-if="Auth.isLogged()">
<a href="" ng-click="Auth.logout()">logout</a>
</li>
<li>
<pre>logged in: {{ Auth.isLogged() }}</pre>
</li>
</ul>
</nav>