Highlight lessons with documentations. Advances #9.

biscuit/apps/alsijil/templates/alsijil/group_week.html

@@ -39,7 +39,13 @@
               </thead>
               <tbody>
                 {% for period in periods %}
-                  <tr>
+                  <tr class="
+                    {% if period.has_documentation %}
+                      table-success
+                    {% else %}
+                      table-warning
+                    {% endif %}
+                  ">
                     <td>{{ period.period.period }}</td>
                     <td>
                       <a href="{% url 'lesson_by_week_and_period' week period.id %}">