feat: add & expose courseware.use_learning_sequences_api flag

lms/djangoapps/courseware/toggles.py

@@ -25,6 +25,23 @@
     WAFFLE_FLAG_NAMESPACE, 'use_legacy_frontend', __name__
 )
 
+# .. toggle_name: courseware.use_learning_sequences_api
+# .. toggle_implementation: CourseWaffleFlag
+# .. toggle_default: False
+# .. toggle_description: When enbled, frontend-app-learning's courseware pages should use the
+#   new Learning Sequences API (from ``openedx.core.djangoapps.content.learning_sequences``)
+#   instead of the Course Blocks API (from ``lms.djangoapps.course_api.blocks``)
+#   in order to load course structure data.
+# .. toggle_warnings: As of 2021-06-25, the frontend-app-learning changes necessary to honor this
+#   flag's value have not yet been implemented. We expect that they will be implemented in
+#   the coming weeks.
+# .. toggle_use_cases: temporary
+# .. toggle_creation_date: 2021-06-25
+# .. toggle_target_removal_date: 2021-09-01
+COURSEWARE_USE_LEARNING_SEQUENCES_API = CourseWaffleFlag(
+    WAFFLE_FLAG_NAMESPACE, 'use_learning_sequences_api', __name__
+)
+
 # .. toggle_name: courseware.microfrontend_course_team_preview
 # .. toggle_implementation: CourseWaffleFlag
 # .. toggle_default: False

openedx/core/djangoapps/courseware_api/serializers.py

@@ -116,6 +116,7 @@ class CourseInfoSerializer(serializers.Serializer):  # pylint: disable=abstract-
     verify_identity_url = AbsoluteURLField()
     verification_status = serializers.CharField()
     linkedin_add_to_profile_url = serializers.URLField()
+    is_learning_sequences_api_enabled = serializers.BooleanField()
     is_mfe_special_exams_enabled = serializers.BooleanField()
     is_mfe_proctored_exams_enabled = serializers.BooleanField()
     user_needs_integrity_signature = serializers.BooleanField()

openedx/core/djangoapps/courseware_api/tests/test_views.py

@@ -28,6 +28,7 @@
     COURSEWARE_MICROFRONTEND_PROGRESS_MILESTONES_STREAK_CELEBRATION,
     COURSEWARE_MICROFRONTEND_SPECIAL_EXAMS,
     COURSEWARE_MICROFRONTEND_PROCTORED_EXAMS,
+    COURSEWARE_USE_LEARNING_SEQUENCES_API,
 )
 from lms.djangoapps.experiments.testutils import override_experiment_waffle_flag
 from lms.djangoapps.experiments.utils import STREAK_DISCOUNT_EXPERIMENT_FLAG
@@ -294,6 +295,17 @@ def test_can_load_courseware(
         else:
             assert not response.data['can_load_courseware']['has_access']
 
+    @ddt.data(True, False)
+    def test_is_learning_sequences_api_enabled(self, enable_new_api):
+        """
+        Test that the Courseware API exposes the Learning Sequences API flag.
+        """
+        with override_waffle_flag(COURSEWARE_USE_LEARNING_SEQUENCES_API, active=enable_new_api):
+            response = self.client.get(self.url)
+            assert response.status_code == 200
+            courseware_data = response.json()
+            assert courseware_data['is_learning_sequences_api_enabled'] is enable_new_api
+
     def test_streak_data_in_response(self):
         """ Test that metadata endpoint returns data for the streak celebration """
         CourseEnrollment.enroll(self.user, self.course.id, 'audit')

openedx/core/djangoapps/courseware_api/views.py

@@ -40,6 +40,7 @@
     course_exit_page_is_active,
     mfe_special_exams_is_active,
     mfe_proctored_exams_is_active,
+    COURSEWARE_USE_LEARNING_SEQUENCES_API,
 )
 from lms.djangoapps.courseware.views.views import get_cert_data
 from lms.djangoapps.grades.api import CourseGradeFactory
@@ -121,6 +122,23 @@ def is_microfrontend_enabled_for_user(self):
             is_course_staff=self.original_user_is_staff
         )
 
+    @property
+    def is_learning_sequences_api_enabled(self):
+        """
+        Should the Learning Sequences API be used to load course structure data?
+
+        Courseware views in frontend-app-learning need to load course structure data
+        from the backend to display feaures like breadcrumbs, the smart "Next"
+        button, etc. This has been done so far using the Course Blocks API.
+
+        Over the next few weeks (starting 2021-06-25), we will be incrementally
+        transitioning said views to instead use the Learning Sequences API,
+        which we expect to be significantly faster. Once the transition is in
+        progress, this function will surface to frontend-app-learning whether
+        the old Course Blocks API or Learning Sequences API should be used.
+        """
+        return COURSEWARE_USE_LEARNING_SEQUENCES_API.is_enabled(self.course_key)
+
     @property
     def is_mfe_special_exams_enabled(self):
         return settings.FEATURES.get('ENABLE_SPECIAL_EXAMS', False) and mfe_special_exams_is_active(self.course_key)