add link to messages in a group

templates/group/group_view.twig

@@ -12,6 +12,9 @@
       <div class="description" id="description">
         <p>{{group.description}}</p>
       </div>
+      {% if session.userId %}
+      <a href="/groups/{{group.getId}}/messages">Messages</a>
+      {% endif %}
       <div class="extra content" id="icons_users">
         <div class="ui small basic icon buttons">
           {% if group.checkAdmin(session.userId) %}
@@ -23,10 +26,10 @@
           </form>
           <button class="ui button" id="add-user-button"><i class="user plus icon"></i> Add a member </button>
           {% endif %}
-          {% if group.hasUser(session.userId) == false %}
-          <form action="/groups/{{group.getId}}/users/add" method="post">
-            <button type="submit" class="ui button"><i class="user plus icon"></i></button>
-          </form>
+          {% if session.userId and group.hasUser(session.userId) == false %}
+            <form action="/groups/{{group.getId}}/users/add" method="post">
+              <button type="submit" class="ui button"><i class="user plus icon"></i></button>
+            </form>
           {% endif %}
         </div>
       </div>