Enable conditional pre-start-date access to courses

LEARNER-1854

openedx/core/djangoapps/waffle_utils/__init__.py

@@ -247,6 +247,13 @@ class WaffleFlag(object):
         self.flag_name = flag_name
         self.flag_undefined_default = flag_undefined_default
 
+    @property
+    def namespaced_flag_name(self):
+        """
+        Returns the fully namespaced flag name.
+        """
+        return self.waffle_namespace._namespaced_name(self.flag_name)
+
     def is_enabled(self):
         """
         Returns whether or not the flag is enabled.

openedx/features/course_experience/__init__.py

@@ -18,6 +18,9 @@ UNIFIED_COURSE_TAB_FLAG = CourseWaffleFlag(WAFFLE_FLAG_NAMESPACE, 'unified_cours
 # Waffle flag to enable the sock on the footer of the home and courseware pages
 DISPLAY_COURSE_SOCK_FLAG = CourseWaffleFlag(WAFFLE_FLAG_NAMESPACE, 'display_course_sock')
 
+# Waffle flag to let learners access a course before its start date
+COURSE_PRE_START_ACCESS_FLAG = CourseWaffleFlag(WAFFLE_FLAG_NAMESPACE, 'pre_start_access')
+
 # Waffle flag to enable a review page link from the unified home page
 SHOW_REVIEWS_TOOL_FLAG = CourseWaffleFlag(WAFFLE_FLAG_NAMESPACE, 'show_reviews_tool')
 

openedx/features/course_experience/tests/views/test_course_home.py

@@ -2,8 +2,12 @@
 """
 Tests for the course home page.
 """
+import datetime
 import ddt
 import mock
+import pytz
+from waffle.testutils import override_flag
+
 from courseware.tests.factories import StaffFactory
 from django.conf import settings
 from django.core.urlresolvers import reverse
@@ -18,6 +22,7 @@ from xmodule.modulestore import ModuleStoreEnum
 from xmodule.modulestore.tests.django_utils import CourseUserType, SharedModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory, check_mongo_calls
 
+from ... import COURSE_PRE_START_ACCESS_FLAG
 from .helpers import add_course_mode
 from .test_course_updates import create_course_update
 
@@ -142,6 +147,26 @@ class TestCourseHomePage(CourseHomePageTestCase):
                 url = course_home_url(self.course)
                 self.client.get(url)
 
+    @mock.patch.dict('django.conf.settings.FEATURES', {'DISABLE_START_DATES': False})
+    def test_start_date_handling(self):
+        """
+        Verify that the course home page handles start dates correctly.
+        """
+        now = datetime.datetime.now(pytz.UTC)
+        tomorrow = now + datetime.timedelta(days=1)
+        self.course.start = tomorrow
+
+        # The course home page should 404 for a course starting in the future
+        url = course_home_url(self.course)
+        response = self.client.get(url)
+        self.assertRedirects(response, '/dashboard?notlive=Jan+01%2C+2030')
+
+        # With the Waffle flag enabled, the course should be visible
+        with override_flag(COURSE_PRE_START_ACCESS_FLAG.namespaced_flag_name, True):
+            url = course_home_url(self.course)
+            response = self.client.get(url)
+            self.assertEqual(response.status_code, 200)
+
 
 @ddt.ddt
 class TestCourseHomePageAccess(CourseHomePageTestCase):

openedx/features/course_experience/utils.py

@@ -71,9 +71,9 @@ def get_course_outline_block_tree(request, course_id):
         block_types_filter=['course', 'chapter', 'sequential']
     )
 
-    course_outline_root_block = all_blocks['blocks'][all_blocks['root']]
-    populate_children(course_outline_root_block, all_blocks['blocks'])
-    set_last_accessed_default(course_outline_root_block)
-    mark_last_accessed(request.user, course_key, course_outline_root_block)
-
+    course_outline_root_block = all_blocks['blocks'].get(all_blocks['root'], None)
+    if course_outline_root_block:
+        populate_children(course_outline_root_block, all_blocks['blocks'])
+        set_last_accessed_default(course_outline_root_block)
+        mark_last_accessed(request.user, course_key, course_outline_root_block)
     return course_outline_root_block

openedx/features/course_experience/views/course_home.py

@@ -83,14 +83,14 @@ class CourseHomeFragmentView(EdxFragmentView):
             return block
 
         course_outline_root_block = get_course_outline_block_tree(request, course_id)
-        last_accessed_block = get_last_accessed_block(course_outline_root_block)
+        last_accessed_block = get_last_accessed_block(course_outline_root_block) if course_outline_root_block else None
         has_visited_course = bool(last_accessed_block)
         if last_accessed_block:
             resume_course_url = last_accessed_block['lms_web_url']
         else:
-            resume_course_url = course_outline_root_block['lms_web_url']
+            resume_course_url = course_outline_root_block['lms_web_url'] if course_outline_root_block else None
 
-        return (has_visited_course, resume_course_url)
+        return has_visited_course, resume_course_url
 
     def _get_course_handouts(self, request, course):
         """
@@ -141,9 +141,6 @@ class CourseHomeFragmentView(EdxFragmentView):
         # Get the course tools enabled for this user and course
         course_tools = CourseToolsPluginManager.get_enabled_course_tools(request, course_key)
 
-        # Get the course tools enabled for this user and course
-        course_tools = CourseToolsPluginManager.get_enabled_course_tools(request, course_key)
-
         # Render the course home fragment
         context = {
             'request': request,

openedx/features/course_experience/views/course_outline.py

@@ -25,6 +25,8 @@ class CourseOutlineFragmentView(EdxFragmentView):
         course_overview = get_course_overview_with_access(request.user, 'load', course_key, check_if_enrolled=True)
 
         course_block_tree = get_course_outline_block_tree(request, course_id)
+        if not course_block_tree:
+            return None
 
         context = {
             'csrf': csrf(request)['csrf_token'],