Use datetime objects in time field in event tracking

common/djangoapps/track/backends/django.py

@@ -11,8 +11,6 @@ from __future__ import absolute_import
 
 import logging
 
-import dateutil
-
 from django.db import models
 
 from track.backends import BaseBackend
@@ -77,7 +75,6 @@ class DjangoBackend(BaseBackend):
         self.name = name
 
     def send(self, event):
-        event['time'] = dateutil.parser.parse(event['time'])
         field_values = {x: event.get(x, '') for x in LOGFIELDS}
         tldat = TrackingLog(**field_values)
         try:

common/djangoapps/track/backends/logger.py

@@ -8,7 +8,7 @@ import json
 from django.conf import settings
 
 from track.backends import BaseBackend
-
+from track.utils import DateTimeJSONEncoder
 
 log = logging.getLogger('track.backends.logger')
 
@@ -33,7 +33,7 @@ class LoggerBackend(BaseBackend):
         self.event_logger = logging.getLogger(name)
 
     def send(self, event):
-        event_str = json.dumps(event)
+        event_str = json.dumps(event, default=DateTimeJSONEncoder)
 
         # TODO: remove trucation of the serialized event, either at a
         # higher level during the emittion of the event, or by

common/djangoapps/track/tests/test_util.py

@@ -0,0 +1,37 @@
+from datetime import datetime
+import json
+
+from pytz import UTC
+
+from django.test import TestCase
+
+from track.utils import DateTimeJSONEncoder
+
+
+class TestDateTimeJSONEncoder(TestCase):
+    def test_datetime_encoding(self):
+        a_naive_datetime = datetime(2012, 05, 01, 07, 27, 10, 20000)
+        a_tz_datetime = datetime(2012, 05, 01, 07, 27, 10, 20000, tzinfo=UTC)
+        a_date = a_naive_datetime.date()
+        an_iso_datetime = '2012-05-01T07:27:10.020000+00:00'
+        an_iso_date = '2012-05-01'
+
+        obj = {
+            'number': 100,
+            'string': 'hello',
+            'object': {'a': 1},
+            'a_datetime': a_naive_datetime,
+            'a_tz_datetime': a_tz_datetime,
+            'a_date': a_date,
+        }
+
+        to_json = json.dumps(obj, cls=DateTimeJSONEncoder)
+        from_json = json.loads(to_json)
+
+        self.assertEqual(from_json['number'], 100)
+        self.assertEqual(from_json['string'], 'hello')
+        self.assertEqual(from_json['object'], {'a': 1})
+
+        self.assertEqual(from_json['a_datetime'], an_iso_datetime)
+        self.assertEqual(from_json['a_tz_datetime'], an_iso_datetime)
+        self.assertEqual(from_json['a_date'], an_iso_date)

common/djangoapps/track/utils.py

@@ -0,0 +1,30 @@
+"""Utility functions and classes for track backends"""
+
+from datetime import datetime, date
+import json
+
+from pytz import UTC
+
+
+class DateTimeJSONEncoder(json.JSONEncoder):
+    """JSON encoder aware of datetime.datetime and datetime.date objects"""
+
+    def default(self, obj):  # pylint: disable=method-hidden
+        """
+        Serialize datetime and date objects of iso format.
+
+        datatime objects are converted to UTC.
+        """
+
+        if isinstance(obj, datetime):
+            if obj.tzinfo is None:
+                # Localize to UTC naive datetime objects
+                obj = UTC.localize(obj)
+            else:
+                # Convert to UTC datetime objects from other timezones
+                obj = obj.astimezone(UTC)
+            return obj.isoformat()
+        elif isinstance(obj, date):
+            return obj.isoformat()
+
+        return super(DateTimeJSONEncoder, self).default(obj)

common/djangoapps/track/views.py

@@ -1,15 +1,11 @@
-import json
-import logging
 import datetime
 
-import dateutil.parser
 import pytz
 from pytz import UTC
 
 from django.contrib.auth.decorators import login_required
 from django.http import HttpResponse
 from django.shortcuts import redirect
-from django.conf import settings
 
 from django_future.csrf import ensure_csrf_cookie
 
@@ -56,7 +52,7 @@ def user_track(request):
         "event": request.REQUEST['event'],
         "agent": agent,
         "page": request.REQUEST['page'],
-        "time": datetime.datetime.now(UTC).isoformat(),
+        "time": datetime.datetime.now(UTC),
         "host": request.META['SERVER_NAME'],
     }
 
@@ -85,7 +81,7 @@ def server_track(request, event_type, event, page=None):
         "event": event,
         "agent": agent,
         "page": page,
-        "time": datetime.datetime.now(UTC).isoformat(),
+        "time": datetime.datetime.now(UTC),
         "host": request.META['SERVER_NAME'],
     }
 
@@ -130,7 +126,7 @@ def task_track(request_info, task_info, event_type, event, page=None):
         "event": full_event,
         "agent": request_info.get('agent', 'unknown'),
         "page": page,
-        "time": datetime.datetime.utcnow().isoformat(),
+        "time": datetime.datetime.now(UTC),
         "host": request_info.get('host', 'unknown')
     }