"""
This module provides views that proxy to the staff grading backend service.
"""
import json
import logging
from xmodule.open_ended_grading_classes.grading_service_module import GradingService, GradingServiceError
from django.conf import settings
from django.http import HttpResponse, Http404
from courseware.access import has_access
from util.json_request import expect_json
from xmodule.course_module import CourseDescriptor
from student.models import unique_id_for_user
from xmodule.x_module import ModuleSystem
from mitxmako.shortcuts import render_to_string
log = logging.getLogger(__name__)
STAFF_ERROR_MESSAGE = 'Could not contact the external grading server. Please contact the development team. If you do not have a point of contact, you can contact Vik at vik@edx.org.'
class MockStaffGradingService(object):
"""
A simple mockup of a staff grading service, testing.
"""
def __init__(self):
self.cnt = 0
def get_next(self, course_id, location, grader_id):
self.cnt += 1
return json.dumps({'success': True,
'submission_id': self.cnt,
'submission': 'Test submission {cnt}'.format(cnt=self.cnt),
'num_graded': 3,
'min_for_ml': 5,
'num_pending': 4,
'prompt': 'This is a fake prompt',
'ml_error_info': 'ML info',
'max_score': 2 + self.cnt % 3,
'rubric': 'A rubric'})
def get_problem_list(self, course_id, grader_id):
self.cnt += 1
return json.dumps({'success': True,
'problem_list': [
json.dumps({'location': 'i4x://MITx/3.091x/problem/open_ended_demo1',
'problem_name': "Problem 1", 'num_graded': 3, 'num_pending': 5,
'min_for_ml': 10}),
json.dumps({'location': 'i4x://MITx/3.091x/problem/open_ended_demo2',
'problem_name': "Problem 2", 'num_graded': 1, 'num_pending': 5,
'min_for_ml': 10})
]})
def save_grade(self, course_id, grader_id, submission_id, score, feedback, skipped, rubric_scores,
submission_flagged):
return self.get_next(course_id, 'fake location', grader_id)
class StaffGradingService(GradingService):
"""
Interface to staff grading backend.
"""
def __init__(self, config):
config['system'] = ModuleSystem(
ajax_url=None,
track_function=None,
get_module = None,
render_template=render_to_string,
replace_urls=None,
xblock_model_data= {}
)
super(StaffGradingService, self).__init__(config)
self.url = config['url'] + config['staff_grading']
self.login_url = self.url + '/login/'
self.get_next_url = self.url + '/get_next_submission/'
self.save_grade_url = self.url + '/save_grade/'
self.get_problem_list_url = self.url + '/get_problem_list/'
self.get_notifications_url = self.url + "/get_notifications/"
def get_problem_list(self, course_id, grader_id):
"""
Get the list of problems for a given course.
Args:
course_id: course id that we want the problems of
grader_id: who is grading this? The anonymous user_id of the grader.
Returns:
json string with the response from the service. (Deliberately not
writing out the fields here--see the docs on the staff_grading view
in the grading_controller repo)
Raises:
GradingServiceError: something went wrong with the connection.
"""
params = {'course_id': course_id, 'grader_id': grader_id}
return self.get(self.get_problem_list_url, params)
def get_next(self, course_id, location, grader_id):
"""
Get the next thing to grade.
Args:
course_id: the course that this problem belongs to
location: location of the problem that we are grading and would like the
next submission for
grader_id: who is grading this? The anonymous user_id of the grader.
Returns:
json string with the response from the service. (Deliberately not
writing out the fields here--see the docs on the staff_grading view
in the grading_controller repo)
Raises:
GradingServiceError: something went wrong with the connection.
"""
response = self.get(self.get_next_url,
params={'location': location,
'grader_id': grader_id})
return json.dumps(self._render_rubric(response))
def save_grade(self, course_id, grader_id, submission_id, score, feedback, skipped, rubric_scores,
submission_flagged):
"""
Save a score and feedback for a submission.
Returns:
json dict with keys
'success': bool
'error': error msg, if something went wrong.
Raises:
GradingServiceError if there's a problem connecting.
"""
data = {'course_id': course_id,
'submission_id': submission_id,
'score': score,
'feedback': feedback,
'grader_id': grader_id,
'skipped': skipped,
'rubric_scores': rubric_scores,
'rubric_scores_complete': True,
'submission_flagged': submission_flagged}
return self.post(self.save_grade_url, data=data)
def get_notifications(self, course_id):
params = {'course_id': course_id}
response = self.get(self.get_notifications_url, params)
return response
# don't initialize until staff_grading_service() is called--means that just
# importing this file doesn't create objects that may not have the right config
_service = None
def staff_grading_service():
"""
Return a staff grading service instance--if settings.MOCK_STAFF_GRADING is True,
returns a mock one, otherwise a real one.
Caches the result, so changing the setting after the first call to this
function will have no effect.
"""
global _service
if _service is not None:
return _service
if settings.MOCK_STAFF_GRADING:
_service = MockStaffGradingService()
else:
_service = StaffGradingService(settings.OPEN_ENDED_GRADING_INTERFACE)
return _service
def _err_response(msg):
"""
Return a HttpResponse with a json dump with success=False, and the given error message.
"""
return HttpResponse(json.dumps({'success': False, 'error': msg}),
mimetype="application/json")
def _check_access(user, course_id):
"""
Raise 404 if user doesn't have staff access to course_id
"""
course_location = CourseDescriptor.id_to_location(course_id)
if not has_access(user, course_location, 'staff'):
raise Http404
return
def get_next(request, course_id):
"""
Get the next thing to grade for course_id and with the location specified
in the request.
Returns a json dict with the following keys:
'success': bool
'submission_id': a unique identifier for the submission, to be passed back
with the grade.
'submission': the submission, rendered as read-only html for grading
'rubric': the rubric, also rendered as html.
'message': if there was no submission available, but nothing went wrong,
there will be a message field.
'error': if success is False, will have an error message with more info.
"""
_check_access(request.user, course_id)
required = set(['location'])
if request.method != 'POST':
raise Http404
actual = set(request.POST.keys())
missing = required - actual
if len(missing) > 0:
return _err_response('Missing required keys {0}'.format(
', '.join(missing)))
grader_id = unique_id_for_user(request.user)
p = request.POST
location = p['location']
return HttpResponse(_get_next(course_id, grader_id, location),
mimetype="application/json")
def get_problem_list(request, course_id):
"""
Get all the problems for the given course id
Returns a json dict with the following keys:
success: bool
problem_list: a list containing json dicts with the following keys:
each dict represents a different problem in the course
location: the location of the problem
problem_name: the name of the problem
num_graded: the number of responses that have been graded
num_pending: the number of responses that are sitting in the queue
min_for_ml: the number of responses that need to be graded before
the ml can be run
"""
_check_access(request.user, course_id)
try:
response = staff_grading_service().get_problem_list(course_id, unique_id_for_user(request.user))
return HttpResponse(response,
mimetype="application/json")
except GradingServiceError:
#This is a dev_facing_error
log.exception("Error from staff grading service in open ended grading. server url: {0}"
.format(staff_grading_service().url))
#This is a staff_facing_error
return HttpResponse(json.dumps({'success': False,
'error': STAFF_ERROR_MESSAGE}))
def _get_next(course_id, grader_id, location):
"""
Implementation of get_next (also called from save_grade) -- returns a json string
"""
try:
return staff_grading_service().get_next(course_id, location, grader_id)
except GradingServiceError:
#This is a dev facing error
log.exception("Error from staff grading service in open ended grading. server url: {0}"
.format(staff_grading_service().url))
#This is a staff_facing_error
return json.dumps({'success': False,
'error': STAFF_ERROR_MESSAGE})
@expect_json
def save_grade(request, course_id):
"""
Save the grade and feedback for a submission, and, if all goes well, return
the next thing to grade.
Expects the following POST parameters:
'score': int
'feedback': string
'submission_id': int
Returns the same thing as get_next, except that additional error messages
are possible if something goes wrong with saving the grade.
"""
_check_access(request.user, course_id)
if request.method != 'POST':
raise Http404
p = request.POST
required = set(['score', 'feedback', 'submission_id', 'location', 'submission_flagged'])
skipped = 'skipped' in p
#If the instructor has skipped grading the submission, then there will not be any rubric scores.
#Only add in the rubric scores if the instructor has not skipped.
if not skipped:
required|=set(['rubric_scores[]'])
actual = set(p.keys())
missing = required - actual
if len(missing) > 0:
return _err_response('Missing required keys {0}'.format(
', '.join(missing)))
grader_id = unique_id_for_user(request.user)
location = p['location']
try:
result_json = staff_grading_service().save_grade(course_id,
grader_id,
p['submission_id'],
p['score'],
p['feedback'],
skipped,
p.getlist('rubric_scores[]'),
p['submission_flagged'])
except GradingServiceError:
#This is a dev_facing_error
log.exception(
"Error saving grade in the staff grading interface in open ended grading. Request: {0} Course ID: {1}".format(
request, course_id))
#This is a staff_facing_error
return _err_response(STAFF_ERROR_MESSAGE)
try:
result = json.loads(result_json)
except ValueError:
#This is a dev_facing_error
log.exception(
"save_grade returned broken json in the staff grading interface in open ended grading: {0}".format(
result_json))
#This is a staff_facing_error
return _err_response(STAFF_ERROR_MESSAGE)
if not result.get('success', False):
#This is a dev_facing_error
log.warning(
'Got success=False from staff grading service in open ended grading. Response: {0}'.format(result_json))
return _err_response(STAFF_ERROR_MESSAGE)
# Ok, save_grade seemed to work. Get the next submission to grade.
return HttpResponse(_get_next(course_id, grader_id, location),
mimetype="application/json")