display certificate generate history in reverse chronological order

lms/djangoapps/certificates/models.py

@@ -294,9 +294,9 @@ class CertificateGenerationHistory(TimeStampedModel):
                 [CertificateStatuses.readable_statuses.get(status, "") for status in statuses]
             )
 
-        # If statuses_to_regenerate is not present in task_input then, certificate generation task was run to
-        # generate certificates for white listed students
-        return "for exceptions"
+        # If students is present in task_input then, certificate generation task was run to
+        # generate certificates for white listed students otherwise it is for all students.
+        return "For exceptions" if 'students' in task_input_json else "All learners"
 
     class Meta(object):
         app_label = "certificates"

lms/djangoapps/instructor/views/api.py

@@ -92,7 +92,7 @@ from instructor.views import INVOICE_KEY
 from submissions import api as sub_api  # installed from the edx-submissions repository
 
 from certificates import api as certs_api
-from certificates.models import CertificateWhitelist, GeneratedCertificate
+from certificates.models import CertificateWhitelist, GeneratedCertificate, CertificateStatuses
 
 from bulk_email.models import CourseEmail
 from student.models import get_user_by_username_or_email
@@ -2708,7 +2708,7 @@ def start_certificate_regeneration(request, course_id):
         )
 
     # Check if the selected statuses are allowed
-    allowed_statuses = GeneratedCertificate.get_unique_statuses(course_key=course_key, flat=True)
+    allowed_statuses = [CertificateStatuses.downloadable, CertificateStatuses.error, CertificateStatuses.notpassing]
     if not set(certificates_statuses).issubset(allowed_statuses):
         return JsonResponse(
             {'message': _('Please select certificate statuses from the list only.')},
@@ -2789,11 +2789,18 @@ def add_certificate_exception(course_key, student, certificate_exception):
         }
     )
 
+    generated_certificate = GeneratedCertificate.objects.filter(
+        user=student,
+        course_id=course_key,
+        status=CertificateStatuses.downloadable,
+    ).first()
+
     exception = dict({
         'id': certificate_white_list.id,
         'user_email': student.email,
         'user_name': student.username,
         'user_id': student.id,
+        'certificate_generated': generated_certificate and generated_certificate.created_date.strftime("%B %d, %Y"),
         'created': certificate_white_list.created.strftime("%A, %B %d, %Y"),
     })
 

lms/djangoapps/instructor/views/instructor_dashboard.py

@@ -324,7 +324,8 @@ def _section_certificates(course):
         'active_certificate': certs_api.get_active_web_certificate(course),
         'certificate_statuses_with_count': certificate_statuses_with_count,
         'status': CertificateStatuses,
-        'certificate_generation_history': CertificateGenerationHistory.objects.filter(course_id=course.id),
+        'certificate_generation_history':
+            CertificateGenerationHistory.objects.filter(course_id=course.id).order_by("-created"),
         'urls': {
             'generate_example_certificates': reverse(
                 'generate_example_certificates',