from collections import defaultdict
from fs.errors import ResourceNotFoundError
from functools import wraps
import logging
import inspect
from lxml.html import rewrite_links
from path import path
from django.conf import settings
from django.core.urlresolvers import reverse
from django.http import Http404
from .module_render import get_module
from xmodule.course_module import CourseDescriptor
from xmodule.modulestore import Location
from xmodule.modulestore.django import modulestore
from xmodule.contentstore.content import StaticContent
from xmodule.modulestore.xml import XMLModuleStore
from xmodule.modulestore.exceptions import ItemNotFoundError
from xmodule.x_module import XModule
from courseware.model_data import ModelDataCache
from static_replace import replace_static_urls
from courseware.access import has_access
import branding
from xmodule.modulestore.exceptions import ItemNotFoundError
log = logging.getLogger(__name__)
def get_request_for_thread():
"""Walk up the stack, return the nearest first argument named "request"."""
frame = None
try:
for f in inspect.stack()[1:]:
frame = f[0]
code = frame.f_code
if code.co_varnames[:1] == ("request",):
return frame.f_locals["request"]
elif code.co_varnames[:2] == ("self", "request",):
return frame.f_locals["request"]
finally:
del frame
def get_course_by_id(course_id, depth=0):
"""
Given a course id, return the corresponding course descriptor.
If course_id is not valid, raises a 404.
depth: The number of levels of children for the modulestore to cache. None means infinite depth
"""
try:
course_loc = CourseDescriptor.id_to_location(course_id)
return modulestore().get_instance(course_id, course_loc, depth=depth)
except (KeyError, ItemNotFoundError):
raise Http404("Course not found.")
def get_course_with_access(user, course_id, action, depth=0):
"""
Given a course_id, look up the corresponding course descriptor,
check that the user has the access to perform the specified action
on the course, and return the descriptor.
Raises a 404 if the course_id is invalid, or the user doesn't have access.
depth: The number of levels of children for the modulestore to cache. None means infinite depth
"""
course = get_course_by_id(course_id, depth=depth)
if not has_access(user, course, action):
# Deliberately return a non-specific error message to avoid
# leaking info about access control settings
raise Http404("Course not found.")
return course
def get_opt_course_with_access(user, course_id, action):
"""
Same as get_course_with_access, except that if course_id is None,
return None without performing any access checks.
"""
if course_id is None:
return None
return get_course_with_access(user, course_id, action)
def course_image_url(course):
"""Try to look up the image url for the course. If it's not found,
log an error and return the dead link"""
if isinstance(modulestore(), XMLModuleStore):
return '/static/' + course.data_dir + "/images/course_image.jpg"
else:
loc = course.location._replace(tag='c4x', category='asset', name='images_course_image.jpg')
path = StaticContent.get_url_path_from_location(loc)
return path
def find_file(fs, dirs, filename):
"""
Looks for a filename in a list of dirs on a filesystem, in the specified order.
fs: an OSFS filesystem
dirs: a list of path objects
filename: a string
Returns d / filename if found in dir d, else raises ResourceNotFoundError.
"""
for d in dirs:
filepath = path(d) / filename
if fs.exists(filepath):
return filepath
raise ResourceNotFoundError("Could not find {0}".format(filename))
def get_course_about_section(course, section_key):
"""
This returns the snippet of html to be rendered on the course about page,
given the key for the section.
Valid keys:
- overview
- title
- university
- number
- short_description
- description
- key_dates (includes start, end, exams, etc)
- video
- course_staff_short
- course_staff_extended
- requirements
- syllabus
- textbook
- faq
- more_info
- ocw_links
"""
# Many of these are stored as html files instead of some semantic
# markup. This can change without effecting this interface when we find a
# good format for defining so many snippets of text/html.
# TODO: Remove number, instructors from this list
if section_key in ['short_description', 'description', 'key_dates', 'video',
'course_staff_short', 'course_staff_extended',
'requirements', 'syllabus', 'textbook', 'faq', 'more_info',
'number', 'instructors', 'overview',
'effort', 'end_date', 'prerequisites', 'ocw_links']:
try:
request = get_request_for_thread()
loc = course.location._replace(category='about', name=section_key)
# Use an empty cache
model_data_cache = ModelDataCache([], course.id, request.user)
about_module = get_module(
request.user,
request,
loc,
model_data_cache,
course.id,
not_found_ok=True,
wrap_xmodule_display=False
)
html = ''
if about_module is not None:
html = about_module.get_html()
return html
except ItemNotFoundError:
log.warning("Missing about section {key} in course {url}".format(
key=section_key, url=course.location.url()))
return None
elif section_key == "title":
return course.display_name_with_default
elif section_key == "university":
return course.location.org
elif section_key == "number":
return course.number
raise KeyError("Invalid about key " + str(section_key))
def get_course_info_section(request, course, section_key):
"""
This returns the snippet of html to be rendered on the course info page,
given the key for the section.
Valid keys:
- handouts
- guest_handouts
- updates
- guest_updates
"""
loc = Location(course.location.tag, course.location.org, course.location.course, 'course_info', section_key)
# Use an empty cache
model_data_cache = ModelDataCache([], course.id, request.user)
info_module = get_module(
request.user,
request,
loc,
model_data_cache,
course.id,
wrap_xmodule_display=False
)
html = ''
if info_module is not None:
html = info_module.get_html()
return html
# TODO: Fix this such that these are pulled in as extra course-specific tabs.
# arjun will address this by the end of October if no one does so prior to
# then.
def get_course_syllabus_section(course, section_key):
"""
This returns the snippet of html to be rendered on the syllabus page,
given the key for the section.
Valid keys:
- syllabus
- guest_syllabus
"""
# Many of these are stored as html files instead of some semantic
# markup. This can change without effecting this interface when we find a
# good format for defining so many snippets of text/html.
if section_key in ['syllabus', 'guest_syllabus']:
try:
fs = course.system.resources_fs
# first look for a run-specific version
dirs = [path("syllabus") / course.url_name, path("syllabus")]
filepath = find_file(fs, dirs, section_key + ".html")
with fs.open(filepath) as htmlFile:
return replace_static_urls(
htmlFile.read().decode('utf-8'),
getattr(course, 'data_dir', None),
course_namespace=course.location
)
except ResourceNotFoundError:
log.exception("Missing syllabus section {key} in course {url}".format(
key=section_key, url=course.location.url()))
return "! Syllabus missing !"
raise KeyError("Invalid about key " + str(section_key))
def get_courses_by_university(user, domain=None):
'''
Returns dict of lists of courses available, keyed by course.org (ie university).
Courses are sorted by course.number.
'''
# TODO: Clean up how 'error' is done.
# filter out any courses that errored.
visible_courses = get_courses(user, domain)
universities = defaultdict(list)
for course in visible_courses:
universities[course.org].append(course)
return universities
def get_courses(user, domain=None):
'''
Returns a list of courses available, sorted by course.number
'''
courses = branding.get_visible_courses(domain)
courses = [c for c in courses if has_access(user, c, 'see_exists')]
courses = sorted(courses, key=lambda course: course.number)
return courses
def sort_by_announcement(courses):
"""
Sorts a list of courses by their announcement date. If the date is
not available, sort them by their start date.
"""
# Sort courses by how far are they from they start day
key = lambda course: course.sorting_score
courses = sorted(courses, key=key)
return courses