Files
edx-platform/cms/djangoapps/models/settings/course_grading.py
2019-07-09 19:14:04 +05:00

288 lines
10 KiB
Python

"""Grading policy"""
from __future__ import absolute_import
import json
from base64 import b64encode
from datetime import timedelta
from hashlib import sha1
import six
from eventtracking import tracker
from contentstore.signals.signals import GRADING_POLICY_CHANGED
from track.event_transaction_utils import create_new_event_transaction_id
from xmodule.modulestore.django import modulestore
GRADING_POLICY_CHANGED_EVENT_TYPE = 'edx.grades.grading_policy_changed'
class CourseGradingModel(object):
"""
Basically a DAO and Model combo for CRUD operations pertaining to grading policy.
"""
# Within this class, allow access to protected members of client classes.
# This comes up when accessing kvs data and caches during kvs saves and modulestore writes.
def __init__(self, course_descriptor):
self.graders = [
CourseGradingModel.jsonize_grader(i, grader) for i, grader in enumerate(course_descriptor.raw_grader)
] # weights transformed to ints [0..100]
self.grade_cutoffs = course_descriptor.grade_cutoffs
self.grace_period = CourseGradingModel.convert_set_grace_period(course_descriptor)
self.minimum_grade_credit = course_descriptor.minimum_grade_credit
@classmethod
def fetch(cls, course_key):
"""
Fetch the course grading policy for the given course from persistence and return a CourseGradingModel.
"""
descriptor = modulestore().get_course(course_key)
model = cls(descriptor)
return model
@staticmethod
def fetch_grader(course_key, index):
"""
Fetch the course's nth grader
Returns an empty dict if there's no such grader.
"""
descriptor = modulestore().get_course(course_key)
index = int(index)
if len(descriptor.raw_grader) > index:
return CourseGradingModel.jsonize_grader(index, descriptor.raw_grader[index])
# return empty model
else:
return {"id": index,
"type": "",
"min_count": 0,
"drop_count": 0,
"short_label": None,
"weight": 0
}
@staticmethod
def update_from_json(course_key, jsondict, user):
"""
Decode the json into CourseGradingModel and save any changes. Returns the modified model.
Probably not the usual path for updates as it's too coarse grained.
"""
descriptor = modulestore().get_course(course_key)
graders_parsed = [CourseGradingModel.parse_grader(jsonele) for jsonele in jsondict['graders']]
descriptor.raw_grader = graders_parsed
descriptor.grade_cutoffs = jsondict['grade_cutoffs']
modulestore().update_item(descriptor, user.id)
CourseGradingModel.update_grace_period_from_json(course_key, jsondict['grace_period'], user)
CourseGradingModel.update_minimum_grade_credit_from_json(course_key, jsondict['minimum_grade_credit'], user)
_grading_event_and_signal(course_key, user.id)
return CourseGradingModel.fetch(course_key)
@staticmethod
def update_grader_from_json(course_key, grader, user):
"""
Create or update the grader of the given type (string key) for the given course. Returns the modified
grader which is a full model on the client but not on the server (just a dict)
"""
descriptor = modulestore().get_course(course_key)
# parse removes the id; so, grab it before parse
index = int(grader.get('id', len(descriptor.raw_grader)))
grader = CourseGradingModel.parse_grader(grader)
if index < len(descriptor.raw_grader):
descriptor.raw_grader[index] = grader
else:
descriptor.raw_grader.append(grader)
modulestore().update_item(descriptor, user.id)
_grading_event_and_signal(course_key, user.id)
return CourseGradingModel.jsonize_grader(index, descriptor.raw_grader[index])
@staticmethod
def update_cutoffs_from_json(course_key, cutoffs, user):
"""
Create or update the grade cutoffs for the given course. Returns sent in cutoffs (ie., no extra
db fetch).
"""
descriptor = modulestore().get_course(course_key)
descriptor.grade_cutoffs = cutoffs
modulestore().update_item(descriptor, user.id)
_grading_event_and_signal(course_key, user.id)
return cutoffs
@staticmethod
def update_grace_period_from_json(course_key, graceperiodjson, user):
"""
Update the course's default grace period. Incoming dict is {hours: h, minutes: m} possibly as a
grace_period entry in an enclosing dict. It is also safe to call this method with a value of
None for graceperiodjson.
"""
descriptor = modulestore().get_course(course_key)
# Before a graceperiod has ever been created, it will be None (once it has been
# created, it cannot be set back to None).
if graceperiodjson is not None:
if 'grace_period' in graceperiodjson:
graceperiodjson = graceperiodjson['grace_period']
grace_timedelta = timedelta(**graceperiodjson)
descriptor.graceperiod = grace_timedelta
modulestore().update_item(descriptor, user.id)
@staticmethod
def update_minimum_grade_credit_from_json(course_key, minimum_grade_credit, user):
"""Update the course's default minimum grade requirement for credit.
Args:
course_key(CourseKey): The course identifier
minimum_grade_json(Float): Minimum grade value
user(User): The user object
"""
descriptor = modulestore().get_course(course_key)
# 'minimum_grade_credit' cannot be set to None
if minimum_grade_credit is not None:
minimum_grade_credit = minimum_grade_credit
descriptor.minimum_grade_credit = minimum_grade_credit
modulestore().update_item(descriptor, user.id)
@staticmethod
def delete_grader(course_key, index, user):
"""
Delete the grader of the given type from the given course.
"""
descriptor = modulestore().get_course(course_key)
index = int(index)
if index < len(descriptor.raw_grader):
del descriptor.raw_grader[index]
# force propagation to definition
descriptor.raw_grader = descriptor.raw_grader
modulestore().update_item(descriptor, user.id)
_grading_event_and_signal(course_key, user.id)
@staticmethod
def delete_grace_period(course_key, user):
"""
Delete the course's grace period.
"""
descriptor = modulestore().get_course(course_key)
del descriptor.graceperiod
modulestore().update_item(descriptor, user.id)
@staticmethod
def get_section_grader_type(location):
descriptor = modulestore().get_item(location)
return {
"graderType": descriptor.format if descriptor.format is not None else 'notgraded',
"location": six.text_type(location),
}
@staticmethod
def update_section_grader_type(descriptor, grader_type, user):
if grader_type is not None and grader_type != u'notgraded':
descriptor.format = grader_type
descriptor.graded = True
else:
del descriptor.format
del descriptor.graded
modulestore().update_item(descriptor, user.id)
_grading_event_and_signal(descriptor.location.course_key, user.id)
return {'graderType': grader_type}
@staticmethod
def convert_set_grace_period(descriptor):
# 5 hours 59 minutes 59 seconds => converted to iso format
rawgrace = descriptor.graceperiod
if rawgrace:
hours_from_days = rawgrace.days * 24
seconds = rawgrace.seconds
hours_from_seconds = int(seconds / 3600)
hours = hours_from_days + hours_from_seconds
seconds -= hours_from_seconds * 3600
minutes = int(seconds / 60)
seconds -= minutes * 60
graceperiod = {'hours': 0, 'minutes': 0, 'seconds': 0}
if hours > 0:
graceperiod['hours'] = hours
if minutes > 0:
graceperiod['minutes'] = minutes
if seconds > 0:
graceperiod['seconds'] = seconds
return graceperiod
else:
return None
@staticmethod
def parse_grader(json_grader):
# manual to clear out kruft
result = {"type": json_grader["type"],
"min_count": int(json_grader.get('min_count', 0)),
"drop_count": int(json_grader.get('drop_count', 0)),
"short_label": json_grader.get('short_label', None),
"weight": float(json_grader.get('weight', 0)) / 100.0
}
return result
@staticmethod
def jsonize_grader(i, grader):
# Warning: converting weight to integer might give unwanted results due
# to the reason how floating point arithmetic works
# e.g, "0.29 * 100 = 28.999999999999996"
return {
"id": i,
"type": grader["type"],
"min_count": grader.get('min_count', 0),
"drop_count": grader.get('drop_count', 0),
"short_label": grader.get('short_label', ""),
"weight": grader.get('weight', 0) * 100,
}
def _grading_event_and_signal(course_key, user_id):
name = GRADING_POLICY_CHANGED_EVENT_TYPE
course = modulestore().get_course(course_key)
grading_policy_hash = six.text_type(hash_grading_policy(course.grading_policy))
data = {
"course_id": six.text_type(course_key),
"user_id": six.text_type(user_id),
"grading_policy_hash": grading_policy_hash,
"event_transaction_id": six.text_type(create_new_event_transaction_id()),
"event_transaction_type": GRADING_POLICY_CHANGED_EVENT_TYPE,
}
tracker.emit(name, data)
GRADING_POLICY_CHANGED.send(
sender=CourseGradingModel,
user_id=user_id,
course_key=course_key,
grading_policy_hash=grading_policy_hash
)
def hash_grading_policy(grading_policy):
ordered_policy = json.dumps(
grading_policy,
separators=(',', ':'), # Remove spaces from separators for more compact representation
sort_keys=True,
)
return b64encode(sha1(ordered_policy).digest())