get the course from CourseOverview table instead of Modulestore in certificates/signals.py.

lms/djangoapps/certificates/signals.py

@@ -5,13 +5,13 @@ from celery.task import task
 from django.dispatch.dispatcher import receiver
 
 from certificates.models import CertificateGenerationCourseSetting
+from openedx.core.djangoapps.content.course_overviews.models import CourseOverview, COURSE_OVERVIEW_UPDATED
 from opaque_keys.edx.keys import CourseKey
-from xmodule.modulestore.django import modulestore, SignalHandler
 
 
-@receiver(SignalHandler.course_published)
+@receiver(COURSE_OVERVIEW_UPDATED)
 def _listen_for_course_publish(sender, course_key, **kwargs):  # pylint: disable=unused-argument
-    """ Catches the signal that a course has been published in Studio and
+    """ Catches the signal that a course overview table has been updated in database and
     enable/disable the self-generated certificates according to course-pacing.
     """
     set_self_generated_certs.delay(unicode(course_key))
@@ -23,5 +23,5 @@ def set_self_generated_certs(course_key):
     Enable or disable self-generated certificates for a course according to pacing.
     """
     course_key = CourseKey.from_string(course_key)
-    course = modulestore().get_course(course_key)
+    course = CourseOverview.get_from_id(course_key)
     CertificateGenerationCourseSetting.set_enabled_for_course(course_key, course.self_paced)

openedx/core/djangoapps/content/course_overviews/models.py

@@ -10,6 +10,7 @@ from django.db import models, transaction
 from django.db.models.fields import BooleanField, DateTimeField, DecimalField, TextField, FloatField, IntegerField
 from django.db.utils import IntegrityError
 from django.template import defaultfilters
+from django.dispatch import Signal
 
 from ccx_keys.locator import CCXLocator
 from model_utils.models import TimeStampedModel
@@ -26,6 +27,7 @@ from xmodule.modulestore.django import modulestore
 from openedx.core.djangoapps.xmodule_django.models import CourseKeyField, UsageKeyField
 from openedx.core.lib.xblock_fields.inherited_fields import DEFAULT_START_DATE
 
+COURSE_OVERVIEW_UPDATED = Signal(providing_args=["course_key"])
 log = logging.getLogger(__name__)
 
 
@@ -646,6 +648,12 @@ class CourseOverview(TimeStampedModel):
         """Represent ourselves with the course key."""
         return unicode(self.id)
 
+    def send_signal(self):
+        """
+        Sends out the signal that course_overview table has been updated.
+        """
+        COURSE_OVERVIEW_UPDATED.send(sender=None, course_key=self.id)
+
 
 class CourseOverviewTab(models.Model):
     """

openedx/core/djangoapps/content/course_overviews/signals.py

@@ -11,9 +11,11 @@ from xmodule.modulestore.django import SignalHandler
 def _listen_for_course_publish(sender, course_key, **kwargs):  # pylint: disable=unused-argument
     """
     Catches the signal that a course has been published in Studio and
-    updates the corresponding CourseOverview cache entry.
+    updates the corresponding CourseOverview cache entry. Also sends out
+    the signal that course_overview table has been updated.
     """
-    CourseOverview.load_from_module_store(course_key)
+    course_overview = CourseOverview.load_from_module_store(course_key)
+    course_overview.send_signal()
 
 
 @receiver(SignalHandler.course_deleted)