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edx-platform/common/lib/capa/capa/capa_problem.py
Calen Pennington 24f85bf202 Merge pull request #340 from MITx/kimth/lms-coderesponse
Kimth/lms coderesponse
2012-08-06 12:17:15 -07:00

516 lines
21 KiB
Python

#
# File: capa/capa_problem.py
#
# Nomenclature:
#
# A capa Problem is a collection of text and capa Response questions. Each Response may have one or more
# Input entry fields. The capa Problem may include a solution.
#
'''
Main module which shows problems (of "capa" type).
This is used by capa_module.
'''
from __future__ import division
import logging
import math
import numpy
import os
import random
import re
import scipy
import struct
import sys
from lxml import etree
from xml.sax.saxutils import unescape
import calc
from correctmap import CorrectMap
import eia
import inputtypes
from util import contextualize_text, convert_files_to_filenames
# to be replaced with auto-registering
import responsetypes
# dict of tagname, Response Class -- this should come from auto-registering
response_tag_dict = dict([(x.response_tag, x) for x in responsetypes.__all__])
entry_types = ['textline', 'schematic', 'textbox', 'imageinput', 'optioninput', 'choicegroup', 'radiogroup', 'checkboxgroup', 'filesubmission']
solution_types = ['solution'] # extra things displayed after "show answers" is pressed
response_properties = ["responseparam", "answer"] # these get captured as student responses
# special problem tags which should be turned into innocuous HTML
html_transforms = {'problem': {'tag': 'div'},
"text": {'tag': 'span'},
"math": {'tag': 'span'},
}
global_context = {'random': random,
'numpy': numpy,
'math': math,
'scipy': scipy,
'calc': calc,
'eia': eia}
# These should be removed from HTML output, including all subelements
html_problem_semantics = ["responseparam", "answer", "script", "hintgroup"]
log = logging.getLogger('mitx.' + __name__)
#-----------------------------------------------------------------------------
# main class for this module
class LoncapaProblem(object):
'''
Main class for capa Problems.
'''
def __init__(self, problem_text, id, state=None, seed=None, system=None):
'''
Initializes capa Problem.
Arguments:
- problem_text (string): xml defining the problem
- id (string): identifier for this problem; often a filename (no spaces)
- state (dict): student state
- seed (int): random number generator seed (int)
- system (ModuleSystem): ModuleSystem instance which provides OS, rendering, and user context
'''
## Initialize class variables from state
self.do_reset()
self.problem_id = id
self.system = system
self.seed = seed
if state:
if 'seed' in state:
self.seed = state['seed']
if 'student_answers' in state:
self.student_answers = state['student_answers']
if 'correct_map' in state:
self.correct_map.set_dict(state['correct_map'])
if 'done' in state:
self.done = state['done']
# TODO: Does this deplete the Linux entropy pool? Is this fast enough?
if not self.seed:
self.seed = struct.unpack('i', os.urandom(4))[0]
problem_text = re.sub("startouttext\s*/", "text", problem_text) # Convert startouttext and endouttext to proper <text></text>
problem_text = re.sub("endouttext\s*/", "/text", problem_text)
self.problem_text = problem_text
self.tree = etree.XML(problem_text) # parse problem XML file into an element tree
self._process_includes() # handle any <include file="foo"> tags
# construct script processor context (eg for customresponse problems)
self.context = self._extract_context(self.tree, seed=self.seed)
# pre-parse the XML tree: modifies it to add ID's and perform some in-place transformations
# this also creates the dict (self.responders) of Response instances for each question in the problem.
# the dict has keys = xml subtree of Response, values = Response instance
self._preprocess_problem(self.tree)
if not self.student_answers: # True when student_answers is an empty dict
self.set_initial_display()
def do_reset(self):
'''
Reset internal state to unfinished, with no answers
'''
self.student_answers = dict()
self.correct_map = CorrectMap()
self.done = False
def set_initial_display(self):
initial_answers = dict()
for responder in self.responders.values():
if hasattr(responder, 'get_initial_display'):
initial_answers.update(responder.get_initial_display())
self.student_answers = initial_answers
def __unicode__(self):
return u"LoncapaProblem ({0})".format(self.problem_id)
def get_state(self):
''' Stored per-user session data neeeded to:
1) Recreate the problem
2) Populate any student answers. '''
return {'seed': self.seed,
'student_answers': self.student_answers,
'correct_map': self.correct_map.get_dict(),
'done': self.done}
def get_max_score(self):
'''
Return maximum score for this problem.
We do this by counting the number of answers available for each question
in the problem. If the Response for a question has a get_max_score() method
then we call that and add its return value to the count. That can be
used to give complex problems (eg programming questions) multiple points.
'''
maxscore = 0
for response, responder in self.responders.iteritems():
if hasattr(responder, 'get_max_score'):
try:
maxscore += responder.get_max_score()
except Exception:
log.debug('responder %s failed to properly return from get_max_score()' % responder) # FIXME
raise
else:
maxscore += len(self.responder_answers[response])
return maxscore
def get_score(self):
'''
Compute score for this problem. The score is the number of points awarded.
Returns a dictionary {'score': integer, from 0 to get_max_score(),
'total': get_max_score()}.
'''
correct = 0
for key in self.correct_map:
try:
correct += self.correct_map.get_npoints(key)
except Exception:
log.error('key=%s, correct_map = %s' % (key, self.correct_map))
raise
if (not self.student_answers) or len(self.student_answers) == 0:
return {'score': 0,
'total': self.get_max_score()}
else:
return {'score': correct,
'total': self.get_max_score()}
def update_score(self, score_msg, queuekey):
'''
Deliver grading response (e.g. from async code checking) to
the specific ResponseType that requested grading
Returns an updated CorrectMap
'''
cmap = CorrectMap()
cmap.update(self.correct_map)
for responder in self.responders.values():
if hasattr(responder, 'update_score'):
# Each LoncapaResponse will update the specific entries of 'cmap' that it's responsible for
cmap = responder.update_score(score_msg, cmap, queuekey)
self.correct_map.set_dict(cmap.get_dict())
return cmap
def is_queued(self):
'''
Returns True if any part of the problem has been submitted to an external queue
'''
queued = False
for answer_id in self.correct_map:
if self.correct_map.is_queued(answer_id):
queued = True
return queued
def grade_answers(self, answers):
'''
Grade student responses. Called by capa_module.check_problem.
answers is a dict of all the entries from request.POST, but with the first part
of each key removed (the string before the first "_").
Thus, for example, input_ID123 -> ID123, and input_fromjs_ID123 -> fromjs_ID123
Calls the Response for each question in this problem, to do the actual grading.
'''
self.student_answers = convert_files_to_filenames(answers)
oldcmap = self.correct_map # old CorrectMap
newcmap = CorrectMap() # start new with empty CorrectMap
# log.debug('Responders: %s' % self.responders)
for responder in self.responders.values(): # Call each responsetype instance to do actual grading
if 'filesubmission' in responder.allowed_inputfields: # File objects are passed only if responsetype
# explicitly allows for file submissions
results = responder.evaluate_answers(answers, oldcmap)
else:
results = responder.evaluate_answers(convert_files_to_filenames(answers), oldcmap)
newcmap.update(results)
self.correct_map = newcmap
# log.debug('%s: in grade_answers, answers=%s, cmap=%s' % (self,answers,newcmap))
return newcmap
def get_question_answers(self):
"""Returns a dict of answer_ids to answer values. If we cannot generate
an answer (this sometimes happens in customresponses), that answer_id is
not included. Called by "show answers" button JSON request
(see capa_module)
"""
answer_map = dict()
for response in self.responders.keys():
results = self.responder_answers[response]
answer_map.update(results) # dict of (id,correct_answer)
# include solutions from <solution>...</solution> stanzas
for entry in self.tree.xpath("//" + "|//".join(solution_types)):
answer = etree.tostring(entry)
if answer: answer_map[entry.get('id')] = answer
log.debug('answer_map = %s' % answer_map)
return answer_map
def get_answer_ids(self):
"""Return the IDs of all the responses -- these are the keys used for
the dicts returned by grade_answers and get_question_answers. (Though
get_question_answers may only return a subset of these."""
answer_ids = []
for response in self.responders.keys():
results = self.responder_answers[response]
answer_ids.append(results.keys())
return answer_ids
def get_html(self):
'''
Main method called externally to get the HTML to be rendered for this capa Problem.
'''
return contextualize_text(etree.tostring(self._extract_html(self.tree)), self.context)
# ======= Private Methods Below ========
def _process_includes(self):
'''
Handle any <include file="foo"> tags by reading in the specified file and inserting it
into our XML tree. Fail gracefully if debugging.
'''
includes = self.tree.findall('.//include')
for inc in includes:
file = inc.get('file')
if file is not None:
try:
ifp = self.system.filestore.open(file) # open using ModuleSystem OSFS filestore
except Exception as err:
log.error('Error %s in problem xml include: %s' % (
err, etree.tostring(inc, pretty_print=True)))
log.error('Cannot find file %s in %s' % (
file, self.system.filestore))
# if debugging, don't fail - just log error
# TODO (vshnayder): need real error handling, display to users
if not self.system.get('DEBUG'):
raise
else:
continue
try:
incxml = etree.XML(ifp.read()) # read in and convert to XML
except Exception as err:
log.error('Error %s in problem xml include: %s' % (
err, etree.tostring(inc, pretty_print=True)))
log.error('Cannot parse XML in %s' % (file))
# if debugging, don't fail - just log error
# TODO (vshnayder): same as above
if not self.system.get('DEBUG'):
raise
else:
continue
# insert new XML into tree in place of inlcude
parent = inc.getparent()
parent.insert(parent.index(inc), incxml)
parent.remove(inc)
log.debug('Included %s into %s' % (file, self.problem_id))
def _extract_system_path(self, script):
'''
Extracts and normalizes additional paths for code execution.
For now, there's a default path of data/course/code; this may be removed
at some point.
'''
DEFAULT_PATH = ['code']
# Separate paths by :, like the system path.
raw_path = script.get('system_path', '').split(":") + DEFAULT_PATH
# find additional comma-separated modules search path
path = []
for dir in raw_path:
if not dir:
continue
# path is an absolute path or a path relative to the data dir
dir = os.path.join(self.system.filestore.root_path, dir)
abs_dir = os.path.normpath(dir)
#log.debug("appending to path: %s" % abs_dir)
path.append(abs_dir)
return path
def _extract_context(self, tree, seed=struct.unpack('i', os.urandom(4))[0]): # private
'''
Extract content of <script>...</script> from the problem.xml file, and exec it in the
context of this problem. Provides ability to randomize problems, and also set
variables for problem answer checking.
Problem XML goes to Python execution context. Runs everything in script tags
'''
random.seed(self.seed)
context = {'global_context': global_context} # save global context in here also
context.update(global_context) # initialize context to have stuff in global_context
context['__builtins__'] = globals()['__builtins__'] # put globals there also
context['the_lcp'] = self # pass instance of LoncapaProblem in
context['script_code'] = ''
self._execute_scripts(tree.findall('.//script'), context)
return context
def _execute_scripts(self, scripts, context):
'''
Executes scripts in the given context.
'''
original_path = sys.path
for script in scripts:
sys.path = original_path + self._extract_system_path(script)
stype = script.get('type')
if stype:
if 'javascript' in stype:
continue # skip javascript
if 'perl' in stype:
continue # skip perl
# TODO: evaluate only python
code = script.text
XMLESC = {"&apos;": "'", "&quot;": '"'}
code = unescape(code, XMLESC)
context['script_code'] += code # store code source in context
try:
exec code in context, context # use "context" for global context; thus defs in code are global within code
except Exception:
log.exception("Error while execing script code: " + code)
raise responsetypes.LoncapaProblemError("Error while executing script code")
finally:
sys.path = original_path
def _extract_html(self, problemtree): # private
'''
Main (private) function which converts Problem XML tree to HTML.
Calls itself recursively.
Returns Element tree of XHTML representation of problemtree.
Calls render_html of Response instances to render responses into XHTML.
Used by get_html.
'''
if problemtree.tag == 'script' and problemtree.get('type') and 'javascript' in problemtree.get('type'):
# leave javascript intact.
return problemtree
if problemtree.tag in html_problem_semantics:
return
problemid = problemtree.get('id') # my ID
if problemtree.tag in inputtypes.get_input_xml_tags():
status = "unsubmitted"
msg = ''
hint = ''
hintmode = None
if problemid in self.correct_map:
pid = problemtree.get('id')
status = self.correct_map.get_correctness(pid)
msg = self.correct_map.get_msg(pid)
hint = self.correct_map.get_hint(pid)
hintmode = self.correct_map.get_hintmode(pid)
value = ""
if self.student_answers and problemid in self.student_answers:
value = self.student_answers[problemid]
# do the rendering
render_object = inputtypes.SimpleInput(system=self.system,
xml=problemtree,
state={'value': value,
'status': status,
'id': problemtree.get('id'),
'feedback': {'message': msg,
'hint': hint,
'hintmode': hintmode,
}
},
use='capa_input')
return render_object.get_html() # function(problemtree, value, status, msg) # render the special response (textline, schematic,...)
if problemtree in self.responders: # let each Response render itself
return self.responders[problemtree].render_html(self._extract_html)
tree = etree.Element(problemtree.tag)
for item in problemtree:
item_xhtml = self._extract_html(item) # nothing special: recurse
if item_xhtml is not None:
tree.append(item_xhtml)
if tree.tag in html_transforms:
tree.tag = html_transforms[problemtree.tag]['tag']
else:
for (key, value) in problemtree.items(): # copy attributes over if not innocufying
tree.set(key, value)
tree.text = problemtree.text
tree.tail = problemtree.tail
return tree
def _preprocess_problem(self, tree): # private
'''
Assign IDs to all the responses
Assign sub-IDs to all entries (textline, schematic, etc.)
Annoted correctness and value
In-place transformation
Also create capa Response instances for each responsetype and save as self.responders
Obtain all responder answers and save as self.responder_answers dict (key = response)
'''
response_id = 1
self.responders = {}
for response in tree.xpath('//' + "|//".join(response_tag_dict)):
response_id_str = self.problem_id + "_" + str(response_id)
response.set('id', response_id_str) # create and save ID for this response
response_id += 1
answer_id = 1
inputfields = tree.xpath("|".join(['//' + response.tag + '[@id=$id]//' + x for x in (entry_types + solution_types)]),
id=response_id_str)
for entry in inputfields: # assign one answer_id for each entry_type or solution_type
entry.attrib['response_id'] = str(response_id)
entry.attrib['answer_id'] = str(answer_id)
entry.attrib['id'] = "%s_%i_%i" % (self.problem_id, response_id, answer_id)
answer_id = answer_id + 1
responder = response_tag_dict[response.tag](response, inputfields, self.context, self.system) # instantiate capa Response
self.responders[response] = responder # save in list in self
# get responder answers (do this only once, since there may be a performance cost, eg with externalresponse)
self.responder_answers = {}
for response in self.responders.keys():
try:
self.responder_answers[response] = self.responders[response].get_answers()
except:
log.debug('responder %s failed to properly return get_answers()' % self.responders[response]) # FIXME
raise
# <solution>...</solution> may not be associated with any specific response; give IDs for those separately
# TODO: We should make the namespaces consistent and unique (e.g. %s_problem_%i).
solution_id = 1
for solution in tree.findall('.//solution'):
solution.attrib['id'] = "%s_solution_%i" % (self.problem_id, solution_id)
solution_id += 1