correctmap.py

#-----------------------------------------------------------------------------
# class used to store graded responses to CAPA questions
#
# Used by responsetypes and capa_problem

class CorrectMap(object):
    '''
    Stores map between answer_id and response evaluation result for each question
    in a capa problem.  The response evaluation result for each answer_id includes
    (correctness, npoints, msg, hint, hintmode).

    - correctness : either 'correct' or 'incorrect'
    - npoints     : None, or integer specifying number of points awarded for this answer_id
    - msg         : string (may have HTML) giving extra message response (displayed below textline or textbox)
    - hint        : string (may have HTML) giving optional hint (displayed below textline or textbox, above msg)
    - hintmode    : one of (None,'on_request','always') criteria for displaying hint

    Behaves as a dict.
    '''
    def __init__(self,*args,**kwargs):
        self.cmap = dict()		# start with empty dict
        self.items = self.cmap.items
        self.keys = self.cmap.keys
        self.set(*args,**kwargs)

    def __getitem__(self, *args, **kwargs):
        return self.cmap.__getitem__(*args, **kwargs)

    def __iter__(self):
        return self.cmap.__iter__()

    def set(self, answer_id=None, correctness=None, npoints=None, msg='', hint='', hintmode=None):
        if answer_id is not None:
            self.cmap[answer_id] = {'correctness': correctness,
                                    'npoints': npoints,
                                    'msg': msg,
                                    'hint' : hint,
                                    'hintmode' : hintmode,
                                    }

    def __repr__(self):
        return repr(self.cmap)

    def get_dict(self):
        '''
        return dict version of self
        '''
        return self.cmap

    def set_dict(self,correct_map):
        '''
        set internal dict to provided correct_map dict
        for graceful migration, if correct_map is a one-level dict, then convert it to the new
        dict of dicts format.
        '''
        if correct_map and not (type(correct_map[correct_map.keys()[0]])==dict):
            self.__init__()							# empty current dict
            for k in correct_map: self.set(k,correct_map[k])			# create new dict entries
        else:
            self.cmap = correct_map

    def is_correct(self,answer_id):
        if answer_id in self.cmap: return self.cmap[answer_id]['correctness'] == 'correct'
        return None

    def get_npoints(self,answer_id):
        if self.is_correct(answer_id):
            npoints = self.cmap[answer_id].get('npoints',1)	# default to 1 point if correct
            return npoints or 1
        return 0						# if not correct, return 0

    def set_property(self,answer_id,property,value):
        if answer_id in self.cmap: self.cmap[answer_id][property] = value
        else: self.cmap[answer_id] = {property:value}

    def get_property(self,answer_id,property,default=None):
        if answer_id in self.cmap: return self.cmap[answer_id].get(property,default)
        return default

    def get_correctness(self,answer_id):
        return self.get_property(answer_id,'correctness')

    def get_msg(self,answer_id):
        return self.get_property(answer_id,'msg','')

    def get_hint(self,answer_id):
        return self.get_property(answer_id,'hint','')

    def get_hintmode(self,answer_id):
        return self.get_property(answer_id,'hintmode',None)

    def set_hint_and_mode(self,answer_id,hint,hintmode):
        '''
          - hint     : (string) HTML text for hint
          - hintmode : (string) mode for hint display ('always' or 'on_request')
        '''
        self.set_property(answer_id,'hint',hint)
        self.set_property(answer_id,'hintmode',hintmode)

    def update(self,other_cmap):
        '''
        Update this CorrectMap with the contents of another CorrectMap
        '''
        if not isinstance(other_cmap,CorrectMap):
            raise Exception('CorrectMap.update called with invalid argument %s' % other_cmap)
        self.cmap.update(other_cmap.get_dict())