Files
edx-platform/lms/djangoapps/course_wiki/utils.py
2013-11-13 01:40:23 +05:00

124 lines
4.3 KiB
Python

"""
Utility functions for course_wiki.
"""
from django.core.exceptions import ObjectDoesNotExist
def user_is_article_course_staff(user, article):
"""
The root of a course wiki is /<course_number>. This means in case there
are two courses which have the same course_number they will end up with
the same course wiki root e.g. MITX/Phy101/Spring and HarvardX/Phy101/Fall
will share /Phy101.
This looks at the course wiki root of the article and returns True if
the user belongs to a group whose name starts with 'instructor_' or
'staff_' and contains '/<course_wiki_root_slug>/'. So if the user is
staff on course MITX/Phy101/Spring they will be in
'instructor_MITX/Phy101/Spring' or 'staff_MITX/Phy101/Spring' groups and
so this will return True.
"""
course_slug = article_course_wiki_root_slug(article)
if course_slug is None:
return False
user_groups = user.groups.all()
# The wiki expects article slugs to contain at least one non-digit so if
# the course number is just a number the course wiki root slug is set to
# be '<course_number>_'. This means slug '202_' can belong to either
# course numbered '202_' or '202' and so we need to consider both.
if user_is_staff_on_course_number(user_groups, course_slug):
return True
if (course_slug.endswith('_') and slug_is_numerical(course_slug[:-1]) and
user_is_staff_on_course_number(user_groups, course_slug[:-1])):
return True
return False
def slug_is_numerical(slug):
"""Returns whether the slug can be interpreted as a number."""
try:
float(slug)
except ValueError:
return False
return True
def course_wiki_slug(course):
"""Returns the slug for the course wiki root."""
slug = course.wiki_slug
# Django-wiki expects article slug to be non-numerical. In case the
# course number is numerical append an underscore.
if slug_is_numerical(slug):
slug = slug + "_"
return slug
def user_is_staff_on_course_number(user_groups, course_number):
"""Returns whether the groups contain a staff group for the course number"""
# Course groups have format 'instructor_<course_id>' and 'staff_<course_id>' where
# course_id = org/course_number/run. So check if user's groups contain a group
# whose name starts with 'instructor_' or 'staff_' and contains '/course_number/'.
course_number_fragment = '/{0}/'.format(course_number)
if [group for group in user_groups if (group.name.startswith(('instructor_', 'staff_')) and
course_number_fragment in group.name)]:
return True
# Old course groups had format 'instructor_<course_number>' and 'staff_<course_number>'
# Check if user's groups contain either of these.
old_instructor_group_name = 'instructor_{0}'.format(course_number)
old_staff_group_name = 'staff_{0}'.format(course_number)
if [group for group in user_groups if (group.name == old_instructor_group_name or
group.name == old_staff_group_name)]:
return True
return False
def article_course_wiki_root_slug(article):
"""
We assume the second level ancestor is the course wiki root. Examples:
/ returns None
/Phy101 returns 'Phy101'
/Phy101/Mechanics returns 'Phy101'
/Chem101/Metals/Iron returns 'Chem101'
Note that someone can create an article /random-article/sub-article on the
wiki. In this case this function will return 'some-random-article' even
if no course with course number 'some-random-article' exists.
"""
try:
urlpath = article.urlpath_set.get()
except ObjectDoesNotExist:
return None
# Ancestors of /Phy101/Mechanics/Acceleration/ is a list of URLPaths
# ['Root', 'Phy101', 'Mechanics']
ancestors = urlpath.cached_ancestors
course_wiki_root_urlpath = None
if len(ancestors) == 0: # It is the wiki root article.
course_wiki_root_urlpath = None
elif len(ancestors) == 1: # It is a course wiki root article.
course_wiki_root_urlpath = urlpath
else: # It is an article inside a course wiki.
course_wiki_root_urlpath = ancestors[1]
if course_wiki_root_urlpath is not None:
return course_wiki_root_urlpath.slug
return None