begin fixing issue 160 - try to not rely on start/end and other attrs…

… actually be set. Refs #160

plone/app/event/base.py

@@ -788,8 +788,13 @@ def dates_for_display(occurrence):
         acc = IEventAccessor(occurrence)
 
     # this needs to separate date and time as ulocalized_time does
-    DT_start = DT(acc.start)
-    DT_end = DT(acc.end)
+    _start = acc.start
+    _end = acc.end
+    _whole_day = acc.whole_day
+    _open_end = acc.open_end
+
+    DT_start = DT(_start)
+    DT_end = DT(_end)
     start_date = ulocalized_time(
         DT_start, long_format=False, time_only=None, context=occurrence
     )
@@ -803,19 +808,17 @@ def dates_for_display(occurrence):
         DT_end, long_format=False, time_only=True, context=occurrence
     )
 
-    same_day = is_same_day(acc.start, acc.end)
-    same_time = is_same_time(acc.start, acc.end)
+    same_day = is_same_day(_start, _end) if _start and _end else None
+    same_time = is_same_time(_start, _end) if _start and _end else None
 
     # set time fields to None for whole day events
-    if acc.whole_day:
+    if _whole_day:
         start_time = end_time = None
-    if acc.open_end:
+    if _open_end:
         end_time = None
 
-    start_iso = acc.whole_day and acc.start.date().isoformat()\
-        or acc.start.isoformat()
-    end_iso = acc.whole_day and acc.end.date().isoformat()\
-        or acc.end.isoformat()
+    start_iso = None if not _start else _start.date().isoformat() if _whole_day else _start.isoformat()  # noqa
+    end_iso = None if not _end else _end.date().isoformat() if _whole_day else end.isoformat()  # noqa
 
     return dict(
         # Start

plone/app/event/browser/event_summary.pt

@@ -26,8 +26,8 @@
     <tal:cond condition="python:'date' not in excludes">
       <dt i18n:translate="event_when">When</dt>
       <dd tal:define="start_tzname data/timezone;
-                      start_utcdelta python:data.start.tzinfo.utcoffset(data.start);
-                      start_utcoffset python:(start_utcdelta.days*86400+start_utcdelta.seconds)*100/60/60;">
+                      start_utcdelta python:data.start.tzinfo.utcoffset(data.start) if data.start else None;
+                      start_utcoffset python:(start_utcdelta.days*86400+start_utcdelta.seconds)*100/60/60 if start_utcdelta else 0;">
         <tal:date replace="structure python:view.formatted_date(context)" />
         <span class="timezone" tal:condition="start_tzname">
          (<tal:tzname replace="start_tzname">timezone name</tal:tzname> / UTC<tal:tzoffset replace="start_utcoffset" />)

plone/app/event/dx/behaviors.py

@@ -667,7 +667,7 @@ def url(self):
 
     @property
     def created(self):
-        return utc(self.context.creation_date)
+        return utc(getattr(self.context, 'creation_date', None))
 
     @property
     def duration(self):
@@ -690,7 +690,7 @@ def description(self, value):
 
     @property
     def last_modified(self):
-        return utc(self.context.modification_date)
+        return utc(getattr(self.context, 'modification_date', None))
     @last_modified.setter
     def last_modified(self, value):
         tz = default_timezone(self.context, as_tzinfo=True)

plone/app/event/ical/exporter.py

@@ -86,7 +86,8 @@ def construct_icalendar(context, events):
 
 
 def add_to_zones_map(tzmap, tzid, dt):
-    if tzid.lower() == 'utc' or not is_datetime(dt):
+
+    if not tzid or not is_datetime(dt) or tzid.lower() == 'utc':
         # no need to define UTC nor timezones for date objects.
         return tzmap
     null = datetime(1, 1, 1)