UPD: trainer email address is now optional.

dav_events/templates/dav_events/event_list.html

@@ -51,10 +51,13 @@
                     <a href="{% url 'dav_events:event_detail' event.pk %}">{{ event.title }}</a>
                 </td>
                 <td>
-                    {% if event.owner.get_full_name %}
-                    {{ event.owner.get_full_name }}<br />{{ event.owner.email }}
+                    {{ event.get_trainer_full_name }}
+                    {% if event.trainer_email %}
+                        <br />{{ event.trainer_email}}
+                    {% elif event.trainer_phone %}
+                        <br />{{ event.trainer_phone}}
                     {% else %}
-                    {{ event.owner }}
+                        <br /><span class="text-danger">{% trans 'Weder E-Mail-Adresse noch Telefonnummer!' %}</span>
                     {% endif %}
                 </td>
                 <td data-order="{{ event.first_day|date:'U' }}">