diff --git a/common/djangoapps/student/models.py b/common/djangoapps/student/models.py
index 89e81d65292a018612f972bd54ab68fa62753d47..056b5141801c78a99d435ad91b2f9d9e6fc635e9 100644
--- a/common/djangoapps/student/models.py
+++ b/common/djangoapps/student/models.py
@@ -589,6 +589,22 @@ class LoginFailures(models.Model):
return
+class CourseEnrollmentException(Exception):
+ pass
+
+class NonExistentCourseError(CourseEnrollmentException):
+ pass
+
+class EnrollmentClosedError(CourseEnrollmentException):
+ pass
+
+class CourseFullError(CourseEnrollmentException):
+ pass
+
+class AlreadyEnrolledError(CourseEnrollmentException):
+ pass
+
+
class CourseEnrollment(models.Model):
"""
Represents a Student's Enrollment record for a single Course. You should
@@ -795,10 +811,59 @@ class CourseEnrollment(models.Model):
until we have these mapped out.
It is expected that this method is called from a method which has already
- verified the user authentication and access.
+ verified the user authentication.
Also emits relevant events for analytics purposes.
"""
+
+ # All the server-side checks for whether a user is allowed to enroll.
+ try:
+ course_id = SlashSeparatedCourseKey.from_deprecated_string(request.POST.get("course_id"))
+ except InvalidKeyError:
+ log.warning(
+ "User {username} tried to {action} with invalid course id: {course_id}".format(
+ username=user.username,
+ action=action,
+ course_id=request.POST.get("course_id")
+ )
+ )
+ raise CourseEnrollmentException
+ try:
+ course = modulestore().get_course(course_id)
+ except ItemNotFoundError:
+ log.warning(
+ "User {0} failed to enroll in non-existent course {1}".format(
+ user.username,
+ course_id
+ )
+ )
+ raise NonExistentCourseError
+ if not has_access(user, 'enroll', course):
+ log.warning(
+ "User {0} failed to enroll in course {1} because enrollment is closed".format(
+ user.username,
+ course_id
+ )
+ )
+ raise EnrollmentClosedError
+ if CourseEnrollment.is_course_full(course):
+ log.warning(
+ "User {0} failed to enroll in full course {1}".format(
+ user.username,
+ course_id
+ )
+ )
+ raise CourseFullError
+ if CourseEnrollment.is_enrolled(user, course_id):
+ log.warning(
+ "User {0} attempted to enroll in {1}, but they were already enrolled".format(
+ user.username,
+ course_id
+ )
+ )
+ raise AlreadyEnrolledError
+
+ # User is allowed to enroll if they've reached this point.
enrollment = cls.get_or_create_enrollment(user, course_key)
enrollment.update_enrollment(is_active=True, mode=mode)
return enrollment
diff --git a/common/djangoapps/student/views.py b/common/djangoapps/student/views.py
index 093f2f5360563658d80a317c980d8f50a3c65388..c43ae54f6f05d88254ab59a6b0a5c4d0097d9bb5 100644
--- a/common/djangoapps/student/views.py
+++ b/common/djangoapps/student/views.py
@@ -661,20 +661,19 @@ def change_enrollment(request, auto_register=False):
Response
"""
+ # Get the user
user = request.user
+ # Ensure we received a course_id
action = request.POST.get("enrollment_action")
if 'course_id' not in request.POST:
return HttpResponseBadRequest(_("Course id not specified"))
- try:
- course_id = SlashSeparatedCourseKey.from_deprecated_string(request.POST.get("course_id"))
- except InvalidKeyError:
- log.warning("User {username} tried to {action} with invalid course id: {course_id}".format(
- username=user.username, action=action, course_id=request.POST.get("course_id")
- ))
- return HttpResponseBadRequest(_("Invalid course id"))
+ # Ensure the user is authenticated
+ if not user.is_authenticated():
+ return HttpResponseForbidden()
+ # Sets the auto_register flag, if that's desired
# TODO (ECOM-16): Remove this once the auto-registration A/B test completes
# If a user is in the experimental condition (auto-registration enabled),
# immediately set a session flag so they stay in the experimental condition.
@@ -686,6 +685,7 @@ def change_enrollment(request, auto_register=False):
if request.session.get('auto_register') and not auto_register:
auto_register = True
+ # Don't execute auto-register for the set of courses excluded from auto-registration
# TODO (ECOM-16): Remove this once the auto-registration A/B test completes
# We've agreed to exclude certain courses from the A/B test. If we find ourselves
# registering for one of these courses, immediately switch to the control.
@@ -694,34 +694,7 @@ def change_enrollment(request, auto_register=False):
if 'auto_register' in request.session:
del request.session['auto_register']
- if not user.is_authenticated():
- return HttpResponseForbidden()
-
if action == "enroll":
- # Make sure the course exists
- # We don't do this check on unenroll, or a bad course id can't be unenrolled from
- try:
- course = modulestore().get_course(course_id)
- except ItemNotFoundError:
- log.warning("User {0} tried to enroll in non-existent course {1}"
- .format(user.username, course_id))
- return HttpResponseBadRequest(_("Course id is invalid"))
-
- if not has_access(user, 'enroll', course):
- return HttpResponseBadRequest(_("Enrollment is closed"))
-
- # see if we have already filled up all allowed enrollments
- is_course_full = CourseEnrollment.is_course_full(course)
-
- if is_course_full:
- return HttpResponseBadRequest(_("Course is full"))
-
- # check to see if user is currently enrolled in that course
- if CourseEnrollment.is_enrolled(user, course_id):
- return HttpResponseBadRequest(
- _("Student is already enrolled")
- )
-
# We use this flag to determine which condition of an AB-test
# for auto-registration we're currently in.
# (We have two URLs that both point to this view, but vary the
@@ -747,7 +720,10 @@ def change_enrollment(request, auto_register=False):
# by its slug. If they do, it's possible (based on the state of the database)
# for no such model to exist, even though we've set the enrollment type
# to "honor".
- CourseEnrollment.enroll(user, course.id)
+ try:
+ CourseEnrollment.enroll(user, course.id, mode=current_mode.slug)
+ except Exception:
+ return HttpResponseBadRequest(_("Could not enroll"))
# If we have more than one course mode or professional ed is enabled,
# then send the user to the choose your track page.
@@ -780,7 +756,10 @@ def change_enrollment(request, auto_register=False):
reverse("course_modes_choose", kwargs={'course_id': unicode(course_id)})
)
- CourseEnrollment.enroll(user, course.id, mode=current_mode.slug)
+ try:
+ CourseEnrollment.enroll(user, course.id, mode=current_mode.slug)
+ except Exception:
+ return HttpResponseBadRequest(_("Could not enroll"))
return HttpResponse()