Files
edx-platform/common/lib/xmodule/xmodule/capa_module.py

583 lines
21 KiB
Python

import datetime
import dateutil
import dateutil.parser
import json
import logging
import traceback
import re
import sys
from datetime import timedelta
from lxml import etree
from pkg_resources import resource_string
from xmodule.x_module import XModule
from xmodule.raw_module import RawDescriptor
from xmodule.exceptions import NotFoundError
from progress import Progress
from capa.capa_problem import LoncapaProblem
from capa.responsetypes import StudentInputError
from capa.util import convert_files_to_filenames
log = logging.getLogger("mitx.courseware")
#-----------------------------------------------------------------------------
TIMEDELTA_REGEX = re.compile(r'^((?P<days>\d+?) day(?:s?))?(\s)?((?P<hours>\d+?) hour(?:s?))?(\s)?((?P<minutes>\d+?) minute(?:s)?)?(\s)?((?P<seconds>\d+?) second(?:s)?)?$')
def only_one(lst, default="", process=lambda x: x):
"""
If lst is empty, returns default
If lst has a single element, applies process to that element and returns it
Otherwise, raises an exeception
"""
if len(lst) == 0:
return default
elif len(lst) == 1:
return process(lst[0])
else:
raise Exception('Malformed XML')
def parse_timedelta(time_str):
"""
time_str: A string with the following components:
<D> day[s] (optional)
<H> hour[s] (optional)
<M> minute[s] (optional)
<S> second[s] (optional)
Returns a datetime.timedelta parsed from the string
"""
parts = TIMEDELTA_REGEX.match(time_str)
if not parts:
return
parts = parts.groupdict()
time_params = {}
for (name, param) in parts.iteritems():
if param:
time_params[name] = int(param)
return timedelta(**time_params)
class ComplexEncoder(json.JSONEncoder):
def default(self, obj):
if isinstance(obj, complex):
return "{real:.7g}{imag:+.7g}*j".format(real=obj.real, imag=obj.imag)
return json.JSONEncoder.default(self, obj)
class CapaModule(XModule):
'''
An XModule implementing LonCapa format problems, implemented by way of
capa.capa_problem.LoncapaProblem
'''
icon_class = 'problem'
js = {'coffee': [resource_string(__name__, 'js/src/capa/display.coffee')],
'js': [resource_string(__name__, 'js/src/capa/imageinput.js'),
resource_string(__name__, 'js/src/capa/schematic.js')]}
js_module_name = "Problem"
css = {'scss': [resource_string(__name__, 'css/capa/display.scss')]}
def __init__(self, system, location, definition, descriptor, instance_state=None,
shared_state=None, **kwargs):
XModule.__init__(self, system, location, definition, descriptor, instance_state,
shared_state, **kwargs)
self.attempts = 0
self.max_attempts = None
dom2 = etree.fromstring(definition['data'])
display_due_date_string = self.metadata.get('due', None)
if display_due_date_string is not None:
self.display_due_date = dateutil.parser.parse(display_due_date_string)
#log.debug("Parsed " + display_due_date_string +
# " to " + str(self.display_due_date))
else:
self.display_due_date = None
grace_period_string = self.metadata.get('graceperiod', None)
if grace_period_string is not None and self.display_due_date:
self.grace_period = parse_timedelta(grace_period_string)
self.close_date = self.display_due_date + self.grace_period
#log.debug("Then parsed " + grace_period_string +
# " to closing date" + str(self.close_date))
else:
self.grace_period = None
self.close_date = self.display_due_date
self.max_attempts = only_one(dom2.xpath('/problem/@attempts'))
if len(self.max_attempts) > 0:
self.max_attempts = int(self.max_attempts)
else:
self.max_attempts = None
self.show_answer = self.metadata.get('showanswer', 'closed')
if self.show_answer == "":
self.show_answer = "closed"
if instance_state is not None:
instance_state = json.loads(instance_state)
if instance_state is not None and 'attempts' in instance_state:
self.attempts = instance_state['attempts']
self.name = only_one(dom2.xpath('/problem/@name'))
weight_string = only_one(dom2.xpath('/problem/@weight'))
if weight_string:
self.weight = float(weight_string)
else:
self.weight = None
if self.rerandomize == 'never':
seed = 1
elif self.rerandomize == "per_student" and hasattr(system, 'id'):
seed = system.id
else:
seed = None
try:
self.lcp = LoncapaProblem(self.definition['data'], self.location.html_id(),
instance_state, seed=seed, system=self.system)
except Exception as err:
msg = 'cannot create LoncapaProblem {loc}: {err}'.format(
loc=self.location.url(), err=err)
# TODO (vshnayder): do modules need error handlers too?
# We shouldn't be switching on DEBUG.
if self.system.DEBUG:
log.error(msg)
# TODO (vshnayder): This logic should be general, not here--and may
# want to preserve the data instead of replacing it.
# e.g. in the CMS
msg = '<p>%s</p>' % msg.replace('<', '&lt;')
msg += '<p><pre>%s</pre></p>' % traceback.format_exc().replace('<', '&lt;')
# create a dummy problem with error message instead of failing
problem_text = ('<problem><text><font color="red" size="+2">'
'Problem %s has an error:</font>%s</text></problem>' %
(self.location.url(), msg))
self.lcp = LoncapaProblem(
problem_text, self.location.html_id(),
instance_state, seed=seed, system=self.system)
else:
# add extra info and raise
raise Exception(msg), None, sys.exc_info()[2]
@property
def rerandomize(self):
"""
Property accessor that returns self.metadata['rerandomize'] in a
canonical form
"""
rerandomize = self.metadata.get('rerandomize', 'always')
if rerandomize in ("", "always", "true"):
return "always"
elif rerandomize in ("false", "per_student"):
return "per_student"
elif rerandomize == "never":
return "never"
else:
raise Exception("Invalid rerandomize attribute " + rerandomize)
def get_instance_state(self):
state = self.lcp.get_state()
state['attempts'] = self.attempts
return json.dumps(state)
def get_score(self):
return self.lcp.get_score()
def max_score(self):
return self.lcp.get_max_score()
def get_progress(self):
''' For now, just return score / max_score
'''
d = self.get_score()
score = d['score']
total = d['total']
if total > 0:
try:
return Progress(score, total)
except Exception as err:
# TODO (vshnayder): why is this still here? still needed?
if self.system.DEBUG:
return None
raise
return None
def get_html(self):
return self.system.render_template('problem_ajax.html', {
'element_id': self.location.html_id(),
'id': self.id,
'ajax_url': self.system.ajax_url,
})
def get_problem_html(self, encapsulate=True):
'''Return html for the problem. Adds check, reset, save buttons
as necessary based on the problem config and state.'''
try:
html = self.lcp.get_html()
except Exception, err:
# TODO (vshnayder): another switch on DEBUG.
if self.system.DEBUG:
log.exception(err)
msg = (
'[courseware.capa.capa_module] <font size="+1" color="red">'
'Failed to generate HTML for problem %s</font>' %
(self.location.url()))
msg += '<p>Error:</p><p><pre>%s</pre></p>' % str(err).replace('<', '&lt;')
msg += '<p><pre>%s</pre></p>' % traceback.format_exc().replace('<', '&lt;')
html = msg
else:
raise
content = {'name': self.metadata['display_name'],
'html': html,
'weight': self.weight,
}
# We using strings as truthy values, because the terminology of the
# check button is context-specific.
check_button = "Grade" if self.max_attempts else "Check"
reset_button = True
save_button = True
# If we're after deadline, or user has exhausted attempts,
# question is read-only.
if self.closed():
check_button = False
reset_button = False
save_button = False
# User submitted a problem, and hasn't reset. We don't want
# more submissions.
if self.lcp.done and self.rerandomize == "always":
check_button = False
save_button = False
# Only show the reset button if pressing it will show different values
if self.rerandomize != 'always':
reset_button = False
# User hasn't submitted an answer yet -- we don't want resets
if not self.lcp.done:
reset_button = False
# We don't need a "save" button if infinite number of attempts and
# non-randomized
if self.max_attempts is None and self.rerandomize != "always":
save_button = False
context = {'problem': content,
'id': self.id,
'check_button': check_button,
'reset_button': reset_button,
'save_button': save_button,
'answer_available': self.answer_available(),
'ajax_url': self.system.ajax_url,
'attempts_used': self.attempts,
'attempts_allowed': self.max_attempts,
'progress': self.get_progress(),
}
html = self.system.render_template('problem.html', context)
if encapsulate:
html = '<div id="problem_{id}" class="problem" data-url="{ajax_url}">'.format(
id=self.location.html_id(), ajax_url=self.system.ajax_url) + html + "</div>"
return self.system.replace_urls(html, self.metadata['data_dir'])
def handle_ajax(self, dispatch, get):
'''
This is called by courseware.module_render, to handle an AJAX call.
"get" is request.POST.
Returns a json dictionary:
{ 'progress_changed' : True/False,
'progress' : 'none'/'in_progress'/'done',
<other request-specific values here > }
'''
handlers = {
'problem_get': self.get_problem,
'problem_check': self.check_problem,
'problem_reset': self.reset_problem,
'problem_save': self.save_problem,
'problem_show': self.get_answer,
'score_update': self.update_score,
}
if dispatch not in handlers:
return 'Error'
before = self.get_progress()
d = handlers[dispatch](get)
after = self.get_progress()
d.update({
'progress_changed': after != before,
'progress_status': Progress.to_js_status_str(after),
})
return json.dumps(d, cls=ComplexEncoder)
def closed(self):
''' Is the student still allowed to submit answers? '''
if self.attempts == self.max_attempts:
return True
if self.close_date is not None and datetime.datetime.utcnow() > self.close_date:
return True
return False
def answer_available(self):
''' Is the user allowed to see an answer?
'''
if self.show_answer == '':
return False
if self.show_answer == "never":
return False
if self.show_answer == 'attempted':
return self.attempts > 0
if self.show_answer == 'answered':
return self.lcp.done
if self.show_answer == 'closed':
return self.closed()
if self.show_answer == 'always':
return True
return False
def update_score(self, get):
"""
Delivers grading response (e.g. from asynchronous code checking) to
the capa problem, so its score can be updated
'get' must have a field 'response' which is a string that contains the
grader's response
No ajax return is needed. Return empty dict.
"""
queuekey = get['queuekey']
score_msg = get['xqueue_body']
self.lcp.update_score(score_msg, queuekey)
return dict() # No AJAX return is needed
def get_answer(self, get):
'''
For the "show answer" button.
TODO: show answer events should be logged here, not just in the problem.js
Returns the answers: {'answers' : answers}
'''
if not self.answer_available():
raise NotFoundError('Answer is not available')
else:
answers = self.lcp.get_question_answers()
return {'answers': answers}
# Figure out if we should move these to capa_problem?
def get_problem(self, get):
''' Return results of get_problem_html, as a simple dict for json-ing.
{ 'html': <the-html> }
Used if we want to reconfirm we have the right thing e.g. after
several AJAX calls.
'''
return {'html': self.get_problem_html(encapsulate=False)}
@staticmethod
def make_dict_of_responses(get):
'''Make dictionary of student responses (aka "answers")
get is POST dictionary.
'''
answers = dict()
for key in get:
# e.g. input_resistor_1 ==> resistor_1
_, _, name = key.partition('_')
# This allows for answers which require more than one value for
# the same form input (e.g. checkbox inputs). The convention is that
# if the name ends with '[]' (which looks like an array), then the
# answer will be an array.
if not name.endswith('[]'):
answers[name] = get[key]
else:
name = name[:-2]
answers[name] = get.getlist(key)
return answers
def check_problem(self, get):
''' Checks whether answers to a problem are correct, and
returns a map of correct/incorrect answers:
{'success' : bool,
'contents' : html}
'''
event_info = dict()
event_info['state'] = self.lcp.get_state()
event_info['problem_id'] = self.location.url()
answers = self.make_dict_of_responses(get)
event_info['answers'] = convert_files_to_filenames(answers)
# Too late. Cannot submit
if self.closed():
event_info['failure'] = 'closed'
self.system.track_function('save_problem_check_fail', event_info)
raise NotFoundError('Problem is closed')
# Problem submitted. Student should reset before checking again
if self.lcp.done and self.rerandomize == "always":
event_info['failure'] = 'unreset'
self.system.track_function('save_problem_check_fail', event_info)
raise NotFoundError('Problem must be reset before it can be checked again')
try:
old_state = self.lcp.get_state()
lcp_id = self.lcp.problem_id
correct_map = self.lcp.grade_answers(answers)
except StudentInputError as inst:
# TODO (vshnayder): why is this line here?
#self.lcp = LoncapaProblem(self.definition['data'],
# id=lcp_id, state=old_state, system=self.system)
log.exception("StudentInputError in capa_module:problem_check")
return {'success': inst.message}
except Exception, err:
# TODO: why is this line here?
#self.lcp = LoncapaProblem(self.definition['data'],
# id=lcp_id, state=old_state, system=self.system)
if self.system.DEBUG:
msg = "Error checking problem: " + str(err)
msg += '\nTraceback:\n' + traceback.format_exc()
return {'success': msg}
log.exception("Error in capa_module problem checking")
raise Exception("error in capa_module")
self.attempts = self.attempts + 1
self.lcp.done = True
# success = correct if ALL questions in this problem are correct
success = 'correct'
for answer_id in correct_map:
if not correct_map.is_correct(answer_id):
success = 'incorrect'
# NOTE: We are logging both full grading and queued-grading submissions. In the latter,
# 'success' will always be incorrect
event_info['correct_map'] = correct_map.get_dict()
event_info['success'] = success
self.system.track_function('save_problem_check', event_info)
# render problem into HTML
html = self.get_problem_html(encapsulate=False)
return {'success': success,
'contents': html,
}
def save_problem(self, get):
'''
Save the passed in answers.
Returns a dict { 'success' : bool, ['error' : error-msg]},
with the error key only present if success is False.
'''
event_info = dict()
event_info['state'] = self.lcp.get_state()
event_info['problem_id'] = self.location.url()
answers = self.make_dict_of_responses(get)
event_info['answers'] = answers
# Too late. Cannot submit
if self.closed():
event_info['failure'] = 'closed'
self.system.track_function('save_problem_fail', event_info)
return {'success': False,
'error': "Problem is closed"}
# Problem submitted. Student should reset before saving
# again.
if self.lcp.done and self.rerandomize == "always":
event_info['failure'] = 'done'
self.system.track_function('save_problem_fail', event_info)
return {'success': False,
'error': "Problem needs to be reset prior to save."}
self.lcp.student_answers = answers
# TODO: should this be save_problem_fail? Looks like success to me...
self.system.track_function('save_problem_fail', event_info)
return {'success': True}
def reset_problem(self, get):
''' Changes problem state to unfinished -- removes student answers,
and causes problem to rerender itself.
Returns problem html as { 'html' : html-string }.
'''
event_info = dict()
event_info['old_state'] = self.lcp.get_state()
event_info['problem_id'] = self.location.url()
if self.closed():
event_info['failure'] = 'closed'
self.system.track_function('reset_problem_fail', event_info)
return "Problem is closed"
if not self.lcp.done:
event_info['failure'] = 'not_done'
self.system.track_function('reset_problem_fail', event_info)
return "Refresh the page and make an attempt before resetting."
self.lcp.do_reset()
if self.rerandomize == "always":
# reset random number generator seed (note the self.lcp.get_state()
# in next line)
self.lcp.seed = None
self.lcp = LoncapaProblem(self.definition['data'],
self.location.html_id(), self.lcp.get_state(),
system=self.system)
event_info['new_state'] = self.lcp.get_state()
self.system.track_function('reset_problem', event_info)
return {'html': self.get_problem_html(encapsulate=False)}
class CapaDescriptor(RawDescriptor):
"""
Module implementing problems in the LON-CAPA format,
as implemented by capa.capa_problem
"""
module_class = CapaModule
stores_state = True
has_score = True
# Capa modules have some additional metadata:
# TODO (vshnayder): do problems have any other metadata? Do they
# actually use type and points?
metadata_attributes = RawDescriptor.metadata_attributes + ('type', 'points')
# VS[compat]
# TODO (cpennington): Delete this method once all fall 2012 course are being
# edited in the cms
@classmethod
def backcompat_paths(cls, path):
return [
'problems/' + path[8:],
path[8:],
]