Pwattenberger/sailthru enroll (#12816)

* Partial changes for purchase tracking

* Continued changes for purchase tracking

* Clean up code quality issues

* Clean up code quality issues

* Responses to code review

* Fix code quality flaged issues

* Fix code quality flaged issues

* Fix code quality flaged issues

* Fix problem processing sailthru_content cookie

common/djangoapps/student/models.py

@@ -61,10 +61,32 @@ from util.milestones_helpers import is_entrance_exams_enabled
 
 
 UNENROLL_DONE = Signal(providing_args=["course_enrollment", "skip_refund"])
+ENROLL_STATUS_CHANGE = Signal(providing_args=["event", "user", "course_id", "mode", "cost", "currency"])
 log = logging.getLogger(__name__)
 AUDIT_LOG = logging.getLogger("audit")
 SessionStore = import_module(settings.SESSION_ENGINE).SessionStore  # pylint: disable=invalid-name
 
+# enroll status changed events - signaled to email_marketing.  See email_marketing.tasks for more info
+
+
+# ENROLL signal used for free enrollment only
+class EnrollStatusChange(object):
+    """
+    Possible event types for ENROLL_STATUS_CHANGE signal
+    """
+    # enroll for a course
+    enroll = 'enroll'
+    # unenroll for a course
+    unenroll = 'unenroll'
+    # add an upgrade to cart
+    upgrade_start = 'upgrade_start'
+    # complete an upgrade purchase
+    upgrade_complete = 'upgrade_complete'
+    # add a paid course to the cart
+    paid_start = 'paid_start'
+    # complete a paid course purchase
+    paid_complete = 'paid_complete'
+
 UNENROLLED_TO_ALLOWEDTOENROLL = 'from unenrolled to allowed to enroll'
 ALLOWEDTOENROLL_TO_ENROLLED = 'from allowed to enroll to enrolled'
 ENROLLED_TO_ENROLLED = 'from enrolled to enrolled'
@@ -1113,6 +1135,7 @@ class CourseEnrollment(models.Model):
                 UNENROLL_DONE.send(sender=None, course_enrollment=self, skip_refund=skip_refund)
 
                 self.emit_event(EVENT_NAME_ENROLLMENT_DEACTIVATED)
+                self.send_signal(EnrollStatusChange.unenroll)
 
                 dog_stats_api.increment(
                     "common.student.unenrollment",
@@ -1125,6 +1148,24 @@ class CourseEnrollment(models.Model):
             # mode has changed from its previous setting
             self.emit_event(EVENT_NAME_ENROLLMENT_MODE_CHANGED)
 
+    def send_signal(self, event, cost=None, currency=None):
+        """
+        Sends a signal announcing changes in course enrollment status.
+        """
+        ENROLL_STATUS_CHANGE.send(sender=None, event=event, user=self.user,
+                                  mode=self.mode, course_id=self.course_id,
+                                  cost=cost, currency=currency)
+
+    @classmethod
+    def send_signal_full(cls, event, user=user, mode=mode, course_id=course_id, cost=None, currency=None):
+        """
+        Sends a signal announcing changes in course enrollment status.
+        This version should be used if you don't already have a CourseEnrollment object
+        """
+        ENROLL_STATUS_CHANGE.send(sender=None, event=event, user=user,
+                                  mode=mode, course_id=course_id,
+                                  cost=cost, currency=currency)
+
     def emit_event(self, event_name):
         """
         Emits an event to explicitly track course enrollment and unenrollment.

common/djangoapps/student/views.py

@@ -112,7 +112,7 @@ from student.helpers import (
     DISABLE_UNENROLL_CERT_STATES,
 )
 from student.cookies import set_logged_in_cookies, delete_logged_in_cookies
-from student.models import anonymous_id_for_user, UserAttribute
+from student.models import anonymous_id_for_user, UserAttribute, EnrollStatusChange
 from shoppingcart.models import DonationConfiguration, CourseRegistrationCode
 
 from embargo import api as embargo_api
@@ -1065,7 +1065,8 @@ def change_enrollment(request, check_access=True):
             try:
                 enroll_mode = CourseMode.auto_enroll_mode(course_id, available_modes)
                 if enroll_mode:
-                    CourseEnrollment.enroll(user, course_id, check_access=check_access, mode=enroll_mode)
+                    enrollment = CourseEnrollment.enroll(user, course_id, check_access=check_access, mode=enroll_mode)
+                    enrollment.send_signal(EnrollStatusChange.enroll)
             except Exception:  # pylint: disable=broad-except
                 return HttpResponseBadRequest(_("Could not enroll"))