Don't show iCal link for courses without start/end times

Full-day events don't show up well in the iCal export. That would
be nice to fix, but for now, let's just not show them.

Author: encukou

naucse/routes.py

@@ -333,13 +333,12 @@ def course_calendar_ics(course):
     if not course.start_date:
         abort(404)
     calendar = ics.Calendar()
-    for session in course.sessions.values():        
+    for session in course.sessions.values():
         if session.start_time:
             start_time = session.start_time
             end_time = session.end_time
         else:
-            start_time = datetime.datetime.combine(session.date, datetime.time())
-            end_time = None
+            abort(404)
         cal_event = ics.Event(
             name = session.title,
             begin = start_time,

naucse/templates/course_calendar.html

@@ -28,10 +28,14 @@ <h1>{{ course.title }}</h1>
     {% if course.subtitle is defined and course.subtitle != None %}
         <h2>{{ course.subtitle }}</h2>
     {% endif%}
-    <div>
-      Přidej si kurz do svého kalendáře:
-      <a href="{{ url_for('course_calendar_ics', course=course) }}">iCal</a>
-    </div>
+    {% if course.default_start_time %}
+        <div>
+            Přidej si kurz do svého kalendáře:
+            <a href="{{ url_for('course_calendar_ics', course=course) }}">iCal</a>
+        </div>
+    {% else %}
+        <!-- iCal link missing because course doesn't have info about start/end times. -->
+    {% endif%}
     {% if course.start_date %}
         {% for year, month in months %}
             <h3 class="calendar-heading">