{% if user.is_authenticated %}
<span class="user_name">{{ user.get_full_name }}</span> | 
<a href='{% url django.contrib.auth.views.logout %}?next_page={{request.get_full_path}}'>Wyloguj</a>
{% else %}
<a href='{% url django.contrib.auth.views.login %}?next_page={{request.get_full_path}}'>Logowanie</a>
{% endif %}