Add string decoding support and tests to xblock.mixin.DateTuple

cms/lib/xblock/mixin.py

@@ -3,17 +3,50 @@ Mixin defining common Studio functionality
 """
 
 import datetime
+import dateutil.parser
+import logging
 import time
 
+from pytz import UTC
+
 from xblock.fields import Scope, Field, Integer, XBlockMixin
 
+log = logging.getLogger(__name__)
+
 
 class DateTuple(Field):
     """
     Field that stores datetime objects as time tuples
     """
+    # See note below about not defaulting these
+    CURRENT_YEAR = datetime.datetime.now(UTC).year
+    PREVENT_DEFAULT_DAY_MON_SEED1 = datetime.datetime(CURRENT_YEAR, 1, 1, tzinfo=UTC)
+    PREVENT_DEFAULT_DAY_MON_SEED2 = datetime.datetime(CURRENT_YEAR, 2, 2, tzinfo=UTC)
+
+    MUTABLE = False
+
+    def _parse_date_wo_default_month_day(self, field):
+        """
+        Parse the field as an iso string but prevent dateutils from defaulting the day or month while
+        allowing it to default the other fields.
+        """
+        # It's not trivial to replace dateutil b/c parsing timezones as Z, +03:30, -400 is hard in python
+        # however, we don't want dateutil to default the month or day (but some tests at least expect
+        # us to default year); so, we'll see if dateutil uses the defaults for these the hard way
+        result = dateutil.parser.parse(field, default=self.PREVENT_DEFAULT_DAY_MON_SEED1)
+        result_other = dateutil.parser.parse(field, default=self.PREVENT_DEFAULT_DAY_MON_SEED2)
+        if result != result_other:
+            log.warning("Field {0} is missing month or day".format(self._name, field))
+            return None
+        if result.tzinfo is None:
+            result = result.replace(tzinfo=UTC)
+        return result
+
     def from_json(self, value):
-        return datetime.datetime(*value[0:6])
+        if value is None:
+            return None
+
+        return datetime.datetime(*value[0:6]).replace(tzinfo=UTC)
 
     def to_json(self, value):
         if value is None:
@@ -22,13 +55,24 @@ class DateTuple(Field):
         return list(value.timetuple())
 
     def enforce_type(self, value):
-        if isinstance(value, datetime.datetime) or value is None:
+        if value == "" or value is None:
+            return None
+
+        if isinstance(value, datetime.datetime):
+            if value.tzinfo is None:
+                value = value.replace(tzinfo=UTC)
             return value
 
-        if isinstance(value, (tuple, time.struct_time)):
-            return datetime.datetime(*value[0:6])
+        if isinstance(value, tuple):
+            return datetime.datetime(*value[0:6]).replace(tzinfo=UTC)
+
+        if isinstance(value, time.struct_time):
+            return datetime.datetime.fromtimestamp(time.mktime(value), UTC)
+
+        if isinstance(value, basestring):
+            return self._parse_date_wo_default_month_day(value)
 
-        raise TypeError("Value should be datetime, a timetuple or None, not {}".format(type(value)))
+        raise TypeError("Value should be datetime, timetuple, str or None, not {}".format(type(value)))
 
 
 class CmsBlockMixin(XBlockMixin):

cms/lib/xblock/test/test_mixin.py

+import unittest
+import datetime
+import time
+
+from pytz import UTC
+
+from cms.lib.xblock.mixin import DateTuple
+
+class DateTupleTest(unittest.TestCase):
+    datetuple = DateTuple()
+
+    def test_from_json(self):
+        '''Test conversion from iso compatible date strings to struct_time'''
+        self.assertEqual(
+            DateTupleTest.datetuple.from_json((2014, 5, 9, 21, 1, 27)),
+            datetime.datetime(2014, 5, 9, 21, 1, 27, tzinfo=UTC))
+        self.assertIsNone(DateTupleTest.datetuple.from_json(None))
+
+    def test_enforce_type(self):
+        self.assertEqual(DateTupleTest.datetuple.enforce_type(
+            (2014, 5, 9, 21, 1, 27)),
+            datetime.datetime(2014, 5, 9, 21, 1, 27, tzinfo=UTC))
+        self.assertEqual(DateTupleTest.datetuple.enforce_type(
+            time.struct_time((2014, 5, 9, 21, 1, 27, 0, 0, 0))),
+            datetime.datetime(2014, 5, 9, 21, 1, 27, tzinfo=UTC))
+        self.assertEqual(DateTupleTest.datetuple.enforce_type(
+            datetime.datetime(2014, 5, 9, 21, 1, 27)),
+            datetime.datetime(2014, 5, 9, 21, 1, 27, tzinfo=UTC))
+        self.assertEqual(DateTupleTest.datetuple.enforce_type(
+            "2013-01-01T00:00:00Z"),
+            datetime.datetime(2013, 1, 1, 00, 00, 00, tzinfo=UTC))
+        self.assertEqual(DateTupleTest.datetuple.enforce_type(
+            "2013-01-01 11:44:22"),
+            datetime.datetime(2013, 1, 1, 11, 44, 22, tzinfo=UTC))
+        self.assertEqual(DateTupleTest.datetuple.enforce_type(
+            "2012-12-31T23:59"),
+            datetime.datetime(2012, 12, 31, 23, 59, 00, tzinfo=UTC))
+        self.assertIsNone(DateTupleTest.datetuple.enforce_type(None))
+        self.assertIsNone(DateTupleTest.datetuple.enforce_type(""))
+
+    def test_to_json(self):
+        self.assertEqual(DateTupleTest.datetuple.to_json(
+            datetime.datetime(2014, 5, 9, 21, 1, 27, tzinfo=UTC))[:6],
+            [2014, 5, 9, 21, 1, 27])
+        self.assertIsNone(DateTupleTest.datetuple.to_json(None))