Files
edx-platform/openedx/features/course_duration_limits/access.py

238 lines
10 KiB
Python

# -*- coding: utf-8 -*-
"""
Contains code related to computing content gating course duration limits
and course access based on these limits.
"""
from datetime import timedelta
from django.utils import timezone
from django.utils.translation import get_language, ugettext as _
from student.models import CourseEnrollment
from util.date_utils import strftime_localized
from course_modes.models import CourseMode
from lms.djangoapps.courseware.access_response import AccessError
from lms.djangoapps.courseware.access_utils import ACCESS_GRANTED
from lms.djangoapps.courseware.date_summary import verified_upgrade_deadline_link
from lms.djangoapps.courseware.masquerade import get_course_masquerade, is_masquerading_as_specific_student
from openedx.core.djangoapps.catalog.utils import get_course_run_details
from openedx.core.djangoapps.content.course_overviews.models import CourseOverview
from openedx.core.djangolib.markup import HTML
from openedx.features.course_duration_limits.models import CourseDurationLimitConfig
from web_fragments.fragment import Fragment
MIN_DURATION = timedelta(weeks=4)
MAX_DURATION = timedelta(weeks=18)
EXPIRATION_DATE_FORMAT_STR = u'%b. %-d, %Y'
class AuditExpiredError(AccessError):
"""
Access denied because the user's audit timespan has expired
"""
def __init__(self, user, course, expiration_date):
error_code = "audit_expired"
developer_message = u"User {} had access to {} until {}".format(user, course, expiration_date)
language = get_language()
expiration_date = strftime_localized(expiration_date, EXPIRATION_DATE_FORMAT_STR)
user_message = _(u"Access expired on {expiration_date}").format(expiration_date=expiration_date)
try:
course_name = course.display_name_with_default
additional_context_user_message = _(u"Access to {course_name} expired on {expiration_date}").format(
course_name=course_name,
expiration_date=expiration_date
)
except CourseOverview.DoesNotExist:
additional_context_user_message = _(u"Access to the course you were looking"
u" for expired on {expiration_date}").format(
expiration_date=expiration_date
)
super(AuditExpiredError, self).__init__(error_code, developer_message, user_message,
additional_context_user_message)
def get_user_course_expiration_date(user, course):
"""
Return expiration date for given user course pair.
Return None if the course does not expire.
Business Logic:
- Course access duration is bounded by the min and max duration.
- If course fields are missing, default course access duration to MIN_DURATION.
"""
access_duration = MIN_DURATION
verified_mode = CourseMode.verified_mode_for_course(course=course, include_expired=True)
if not verified_mode:
return None
enrollment = CourseEnrollment.get_enrollment(user, course.id)
if enrollment is None or enrollment.mode != CourseMode.AUDIT:
return None
try:
# Content availability date is equivalent to max(enrollment date, course start date)
# for most people. Using the schedule date will provide flexibility to deal with
# more complex business rules in the future.
content_availability_date = enrollment.schedule.start
# We have anecdotally observed a case where the schedule.start was
# equal to the course start, but should have been equal to the enrollment start
# https://openedx.atlassian.net/browse/PROD-58
# This section is meant to address that case
if enrollment.created and course.start:
if (content_availability_date.date() == course.start.date() and
course.start < enrollment.created < timezone.now()):
content_availability_date = enrollment.created
except CourseEnrollment.schedule.RelatedObjectDoesNotExist:
content_availability_date = max(enrollment.created, course.start)
# The user course expiration date is the content availability date
# plus the weeks_to_complete field from course-discovery.
discovery_course_details = get_course_run_details(course.id, ['weeks_to_complete'])
expected_weeks = discovery_course_details.get('weeks_to_complete')
if expected_weeks:
access_duration = timedelta(weeks=expected_weeks)
# Course access duration is bounded by the min and max duration.
access_duration = max(MIN_DURATION, min(MAX_DURATION, access_duration))
return content_availability_date + access_duration
def check_course_expired(user, course):
"""
Check if the course expired for the user.
"""
# masquerading course staff should always have access
if get_course_masquerade(user, course.id):
return ACCESS_GRANTED
if not CourseDurationLimitConfig.enabled_for_enrollment(user=user, course_key=course.id):
return ACCESS_GRANTED
expiration_date = get_user_course_expiration_date(user, course)
if expiration_date and timezone.now() > expiration_date:
return AuditExpiredError(user, course, expiration_date)
return ACCESS_GRANTED
def get_date_string():
# Creating this method to allow unit testing an issue where this string was missing the unicode prefix
return u'<span class="localized-datetime" data-format="shortDate" \
data-datetime="{formatted_date}" data-language="{language}">{formatted_date_localized}</span>'
def generate_course_expired_message(user, course):
"""
Generate the message for the user course expiration date if it exists.
"""
if not CourseDurationLimitConfig.enabled_for_enrollment(user=user, course_key=course.id):
return
expiration_date = get_user_course_expiration_date(user, course)
if not expiration_date:
return
if is_masquerading_as_specific_student(user, course.id) and timezone.now() > expiration_date:
upgrade_message = _('This learner does not have access to this course. '
u'Their access expired on {expiration_date}.')
return HTML(upgrade_message).format(
expiration_date=strftime_localized(expiration_date, EXPIRATION_DATE_FORMAT_STR)
)
else:
enrollment = CourseEnrollment.get_enrollment(user, course.id)
if enrollment is None:
return
upgrade_deadline = enrollment.upgrade_deadline
now = timezone.now()
course_upgrade_deadline = enrollment.course_upgrade_deadline
if (not upgrade_deadline) or (upgrade_deadline < now):
upgrade_deadline = course_upgrade_deadline
expiration_message = _(u'{strong_open}Audit Access Expires {expiration_date}{strong_close}'
u'{line_break}You lose all access to this course, including your progress, on '
u'{expiration_date}.')
upgrade_deadline_message = _(u'{line_break}Upgrade by {upgrade_deadline} to get unlimited access to the course '
u'as long as it exists on the site. {a_open}Upgrade now{sronly_span_open} to '
u'retain access past {expiration_date}{span_close}{a_close}')
full_message = expiration_message
if upgrade_deadline and now < upgrade_deadline:
full_message += upgrade_deadline_message
using_upgrade_messaging = True
else:
using_upgrade_messaging = False
language = get_language()
date_string = get_date_string()
formatted_expiration_date = date_string.format(
language=language,
formatted_date=expiration_date.strftime(EXPIRATION_DATE_FORMAT_STR),
formatted_date_localized=strftime_localized(expiration_date, EXPIRATION_DATE_FORMAT_STR)
)
if using_upgrade_messaging:
formatted_upgrade_deadline = date_string.format(
language=language,
formatted_date=upgrade_deadline.strftime(EXPIRATION_DATE_FORMAT_STR),
formatted_date_localized=strftime_localized(upgrade_deadline, EXPIRATION_DATE_FORMAT_STR)
)
return HTML(full_message).format(
a_open=HTML(u'<a href="{upgrade_link}">').format(
upgrade_link=verified_upgrade_deadline_link(user=user, course=course)
),
sronly_span_open=HTML('<span class="sr-only">'),
span_close=HTML('</span>'),
a_close=HTML('</a>'),
expiration_date=HTML(formatted_expiration_date),
strong_open=HTML('<strong>'),
strong_close=HTML('</strong>'),
line_break=HTML('<br>'),
upgrade_deadline=HTML(formatted_upgrade_deadline)
)
else:
return HTML(full_message).format(
span_close=HTML('</span>'),
expiration_date=HTML(formatted_expiration_date),
strong_open=HTML('<strong>'),
strong_close=HTML('</strong>'),
line_break=HTML('<br>'),
)
def generate_course_expired_fragment(user, course):
message = generate_course_expired_message(user, course)
if message:
return Fragment(HTML(u"""\
<div class="course-expiration-message">{}</div>
""").format(message))
def course_expiration_wrapper(user, block, view, frag, context): # pylint: disable=W0613
"""
An XBlock wrapper that prepends a message to the beginning of a vertical if
a user's course is about to expire.
"""
if block.category != "vertical":
return frag
course = CourseOverview.get_from_id(block.course_id)
course_expiration_fragment = generate_course_expired_fragment(user, course)
if not course_expiration_fragment:
return frag
# Course content must be escaped to render correctly due to the way the
# way the XBlock rendering works. Transforming the safe markup to unicode
# escapes correctly.
course_expiration_fragment.content = unicode(course_expiration_fragment.content)
course_expiration_fragment.add_content(frag.content)
course_expiration_fragment.add_fragment_resources(frag)
return course_expiration_fragment