Add Adhoc frequency

For the irc-meetings we would like to list the possiblity of a meeting
but not actually formally schedule it. This change allows for an AdHoc
meeting which is essentially a noop in the ical generation

Change-Id: I843b5b3f2a6e5a74b85b13b86c8d16125a1ac7c7

yaml2ical/ical.py

@@ -81,6 +81,11 @@ class Yaml2IcalCalendar(icalendar.Calendar):
                 # get starting date
                 next_meeting = sch.recurrence.next_occurence(sch.start_date,
                                                              sch.day)
+                # NOTE(aschultz): to handle adhoc meetings, we check to make
+                # sure there is a next meeting before trying to add it to the
+                # the calendar
+                if next_meeting is None:
+                    return
                 next_meeting_date = datetime.datetime(next_meeting.year,
                                                       next_meeting.month,
                                                       next_meeting.day,

yaml2ical/recurrence.py

@@ -78,8 +78,32 @@ class BiWeeklyRecurrence(object):
         return "Every two weeks (on %s weeks)" % self.style
 
 
+class AdhocRecurrence(object):
+    """Meetings occuring as needed.
+
+    Effectively this is a noop recurrance as next_occurance is always None
+    """
+    def __init__(self):
+        pass
+
+    def next_occurence(self, current_date, day):
+        """Calculate the next adhoc meeting.
+
+        :param current_date: the current date
+        :param day: scheduled day of the meeting
+        :returns: datetime object of next meeting
+        """
+        return None
+
+    def rrule(self):
+        return {'freq': 'adhoc', 'interval': 0}
+
+    def __str__(self):
+        return "Occurs as needed, no fixed schedule."
+
 supported_recurrences = {
     'weekly': WeeklyRecurrence(),
     'biweekly-odd': BiWeeklyRecurrence(style='odd'),
     'biweekly-even': BiWeeklyRecurrence(),
+    'adhoc': AdhocRecurrence(),
 }

yaml2ical/tests/sample_data.py

@@ -258,3 +258,17 @@ chair: Shannon Stacker
 description: >
     Weekly short meeting for Subteam project.
 """
+
+# adhoc meeting
+ADHOC_MEETING = """
+project: OpenStack Random Meeting
+schedule:
+  - time: '1200'
+    day: Monday
+    start_date: 20150801
+    irc: openstack-meeting
+    frequency: adhoc
+chair: Shannon Stacker
+description: >
+    Adhoc random meeting for Subteam project.
+"""

yaml2ical/tests/test_meeting.py

@@ -116,6 +116,13 @@ class MeetingTestCase(unittest.TestCase):
         for p in patterns:
             self.assertNotEqual(None, p.match(cal_str))
 
+    def test_adhoc_meeting(self):
+        meeting_yaml = sample_data.ADHOC_MEETING
+        m = meeting.load_meetings(meeting_yaml)[0]
+        cal = ical.Yaml2IcalCalendar()
+        cal.add_meeting(m)
+        self.assertEqual(cal, ical.Yaml2IcalCalendar())
+
     def test_skip_meeting_missing_skip_date(self):
         self.assertRaises(KeyError,
                           meeting.load_meetings,

yaml2ical/tests/test_recurrence.py

@@ -37,3 +37,8 @@ class RecurrenceTestCase(unittest.TestCase):
         self.assertEqual(
             datetime.datetime(2014, 10, 15, 2, 47, 28, 832666),
             self.next_meeting(recurrence.BiWeeklyRecurrence(style='even')))
+
+    def test_next_adhoc(self):
+        self.assertEqual(
+            None,
+            self.next_meeting(recurrence.AdhocRecurrence()))