Refactor Course Catalog fields in CourseDescriptor

common/lib/xmodule/xmodule/course_metadata_utils.py

@@ -5,9 +5,10 @@ This is a place to put simple functions that operate on course metadata. It
 allows us to share code between the CourseDescriptor and CourseOverview
 classes, which both need these type of functions.
 """
-from datetime import datetime
-from datetime import timedelta
 from base64 import b32encode
+from datetime import datetime, timedelta
+import dateutil.parser
+from math import exp
 
 from django.utils.timezone import UTC
 
@@ -222,3 +223,43 @@ def may_certify_for_course(certificates_display_behavior, certificates_show_befo
         or certificates_show_before_end
     )
     return show_early or has_ended
+
+
+def sorting_score(start, advertised_start, announcement):
+    """
+    Returns a tuple that can be used to sort the courses according
+    to how "new" they are. The "newness" score is computed using a
+    heuristic that takes into account the announcement and
+    (advertised) start dates of the course if available.
+
+    The lower the number the "newer" the course.
+    """
+    # Make courses that have an announcement date have a lower
+    # score than courses than don't, older courses should have a
+    # higher score.
+    announcement, start, now = sorting_dates(start, advertised_start, announcement)
+    scale = 300.0  # about a year
+    if announcement:
+        days = (now - announcement).days
+        score = -exp(-days / scale)
+    else:
+        days = (now - start).days
+        score = exp(days / scale)
+    return score
+
+
+def sorting_dates(start, advertised_start, announcement):
+    """
+    Utility function to get datetime objects for dates used to
+    compute the is_new flag and the sorting_score.
+    """
+    try:
+        start = dateutil.parser.parse(advertised_start)
+        if start.tzinfo is None:
+            start = start.replace(tzinfo=UTC())
+    except (ValueError, AttributeError):
+        start = start
+
+    now = datetime.now(UTC())
+
+    return announcement, start, now

common/lib/xmodule/xmodule/course_module.py

@@ -3,12 +3,10 @@ Django module container for classes and operations related to the "Course Module
 """
 import logging
 from cStringIO import StringIO
-from math import exp
 from lxml import etree
 from path import Path as path
 import requests
 from datetime import datetime
-import dateutil.parser
 from lazy import lazy
 
 from xmodule import course_metadata_utils
@@ -1264,7 +1262,9 @@ class CourseDescriptor(CourseFields, SequenceDescriptor, LicenseMixin):
         flag = self.is_new
         if flag is None:
             # Use a heuristic if the course has not been flagged
-            announcement, start, now = self._sorting_dates()
+            announcement, start, now = course_metadata_utils.sorting_dates(
+                self.start, self.advertised_start, self.announcement
+            )
             if announcement and (now - announcement).days < 30:
                 # The course has been announced for less that month
                 return True
@@ -1284,41 +1284,11 @@ class CourseDescriptor(CourseFields, SequenceDescriptor, LicenseMixin):
         Returns a tuple that can be used to sort the courses according
         the how "new" they are. The "newness" score is computed using a
         heuristic that takes into account the announcement and
-        (advertized) start dates of the course if available.
+        (advertised) start dates of the course if available.
 
         The lower the number the "newer" the course.
         """
-        # Make courses that have an announcement date shave a lower
-        # score than courses than don't, older courses should have a
-        # higher score.
-        announcement, start, now = self._sorting_dates()
-        scale = 300.0  # about a year
-        if announcement:
-            days = (now - announcement).days
-            score = -exp(-days / scale)
-        else:
-            days = (now - start).days
-            score = exp(days / scale)
-        return score
-
-    def _sorting_dates(self):
-        # utility function to get datetime objects for dates used to
-        # compute the is_new flag and the sorting_score
-
-        announcement = self.announcement
-        if announcement is not None:
-            announcement = announcement
-
-        try:
-            start = dateutil.parser.parse(self.advertised_start)
-            if start.tzinfo is None:
-                start = start.replace(tzinfo=UTC())
-        except (ValueError, AttributeError):
-            start = self.start
-
-        now = datetime.now(UTC())
-
-        return announcement, start, now
+        return course_metadata_utils.sorting_score(self.start, self.advertised_start, self.announcement)
 
     @lazy
     def grading_context(self):

common/lib/xmodule/xmodule/tests/test_course_module.py

@@ -150,14 +150,14 @@ class IsNewCourseTestCase(unittest.TestCase):
 
         # Needed for test_is_newish
         datetime_patcher = patch.object(
-            xmodule.course_module, 'datetime',
+            xmodule.course_metadata_utils, 'datetime',
             Mock(wraps=datetime)
         )
         mocked_datetime = datetime_patcher.start()
         mocked_datetime.now.return_value = NOW
         self.addCleanup(datetime_patcher.stop)
 
-    @patch('xmodule.course_module.datetime.now')
+    @patch('xmodule.course_metadata_utils.datetime.now')
     def test_sorting_score(self, gmtime_mock):
         gmtime_mock.return_value = NOW
 
@@ -208,7 +208,7 @@ class IsNewCourseTestCase(unittest.TestCase):
         (xmodule.course_module.CourseFields.start.default, 'January 2014', 'January 2014', False, 'January 2014'),
     ]
 
-    @patch('xmodule.course_module.datetime.now')
+    @patch('xmodule.course_metadata_utils.datetime.now')
     def test_start_date_text(self, gmtime_mock):
         gmtime_mock.return_value = NOW
         for s in self.start_advertised_settings:
@@ -216,7 +216,7 @@ class IsNewCourseTestCase(unittest.TestCase):
             print "Checking start=%s advertised=%s" % (s[0], s[1])
             self.assertEqual(d.start_datetime_text(), s[2])
 
-    @patch('xmodule.course_module.datetime.now')
+    @patch('xmodule.course_metadata_utils.datetime.now')
     def test_start_date_time_text(self, gmtime_mock):
         gmtime_mock.return_value = NOW
         for setting in self.start_advertised_settings: