fourth pass in capa cleanup:

  - Added hints + hintmethod
  - hintgroup compatible with loncapa spec
  - also does hintfn for custom hints (can do answer history)
  - GenericResponse -> LoncapaResponse
  - moved response type tags into responsetype classes
  - capa_problem should use __future__ division
  - hints stored in CorrectMap, copied to 'feedback' in SimpleInput for display

common/lib/capa/capa_problem.py

@@ -12,6 +12,8 @@ Main module which shows problems (of "capa" type).
 This is used by capa_module.
 '''
 
+from __future__ import division
+
 import copy
 import logging
 import math
@@ -32,20 +34,10 @@ import inputtypes
 from util import contextualize_text
 
 # to be replaced with auto-registering
-from responsetypes import NumericalResponse, FormulaResponse, CustomResponse, SchematicResponse, MultipleChoiceResponse, TrueFalseResponse, ExternalResponse, ImageResponse, OptionResponse, SymbolicResponse
+import responsetypes
 
 # dict of tagname, Response Class -- this should come from auto-registering
-response_types = {'numericalresponse': NumericalResponse,
-                  'formularesponse': FormulaResponse,
-                  'customresponse': CustomResponse,
-                  'schematicresponse': SchematicResponse,
-                  'externalresponse': ExternalResponse,
-                  'multiplechoiceresponse': MultipleChoiceResponse,
-                  'truefalseresponse': TrueFalseResponse,
-                  'imageresponse': ImageResponse,
-                  'optionresponse': OptionResponse,
-                  'symbolicresponse': SymbolicResponse,
-                  }
+response_tag_dict = dict([(x.response_tag,x) for x in responsetypes.__all__])
 
 entry_types = ['textline', 'schematic', 'choicegroup', 'textbox', 'imageinput', 'optioninput']
 solution_types = ['solution']    			# extra things displayed after "show answers" is pressed
@@ -65,7 +57,7 @@ global_context = {'random': random,
                   'eia': eia}
 
 # These should be removed from HTML output, including all subelements
-html_problem_semantics = ["responseparam", "answer", "script"]
+html_problem_semantics = ["responseparam", "answer", "script","hintgroup"]
 
 #log = logging.getLogger(__name__)
 log = logging.getLogger('mitx.common.lib.capa.capa_problem')
@@ -209,7 +201,7 @@ class LoncapaProblem(object):
         oldcmap = self.correct_map				# old CorrectMap
         newcmap = CorrectMap()					# start new with empty CorrectMap
         for responder in self.responders.values():
-            results = responder.get_score(answers,oldcmap)      # call the responsetype instance to do the actual grading
+            results = responder.evaluate_answers(answers,oldcmap)      # call the responsetype instance to do the actual grading
             newcmap.update(results)
         self.correct_map = newcmap
         log.debug('%s: in grade_answers, answers=%s, cmap=%s' % (self,answers,newcmap))
@@ -248,7 +240,8 @@ class LoncapaProblem(object):
         '''
         return contextualize_text(etree.tostring(self.extract_html(self.tree)), self.context)
 
-    # ======= Private ========
+    # ======= Private Methods Below ========
+
     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
@@ -296,15 +289,17 @@ class LoncapaProblem(object):
         problemid = problemtree.get('id')    # my ID
 
         if problemtree.tag in inputtypes.get_input_xml_tags():
-            # status is currently the answer for the problem ID for the input element,
-            # but it will turn into a dict containing both the answer and any associated message
-            # for the problem ID for the input element.
+
             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:
@@ -316,7 +311,10 @@ class LoncapaProblem(object):
                                                    state={'value': value,
                                                           'status': status,
                                                           'id': problemtree.get('id'),
-                                                          'feedback': {'message': msg}
+                                                          '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,...)
@@ -352,7 +350,7 @@ class LoncapaProblem(object):
         '''
         response_id = 1
 	self.responders = {}
-        for response in tree.xpath('//' + "|//".join(response_types)):
+        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
@@ -366,7 +364,7 @@ class LoncapaProblem(object):
                 entry.attrib['id'] = "%s_%i_%i" % (self.problem_id, response_id, answer_id)
                 answer_id = answer_id + 1
 
-            responder = response_types[response.tag](response, inputfields, self.context, self.system)	# instantiate capa Response
+            responder = response_tag_dict[response.tag](response, inputfields, self.context, self.system) # instantiate capa Response
 	    self.responders[response] = responder				# save in list in self
 
         # <solution>...</solution> may not be associated with any specific response; give IDs for those separately

common/lib/capa/correctmap.py

@@ -5,7 +5,16 @@
 
 class CorrectMap(object):
     '''
-    Stores (correctness, npoints, msg) for each answer_id.
+    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.
     '''
     cmap = {}
@@ -13,11 +22,14 @@ class CorrectMap(object):
     def __init__(self,*args,**kwargs):
         self.set(*args,**kwargs)
 
-    def set(self,answer_id=None,correctness=None,npoints=None,msg=''):
+    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 }
+                                    'msg': msg,
+                                    'hint' : hint,
+                                    'hintmode' : hintmode,
+                                    }
 
     def __repr__(self):
         return repr(self.cmap)
@@ -64,6 +76,20 @@ class CorrectMap(object):
     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

common/lib/capa/inputtypes.py

@@ -32,44 +32,57 @@ def get_input_xml_tags():
     return SimpleInput.get_xml_tags()
 
 class SimpleInput():# XModule
-    ''' Type for simple inputs -- plain HTML with a form element
-
-    State is a dictionary with optional keys: 
-    * Value
-    * ID
-    * Status (answered, unanswered, unsubmitted)
-    * Feedback (dictionary containing keys for hints, errors, or other 
-      feedback from previous attempt)
-
+    '''
+    Type for simple inputs -- plain HTML with a form element
     '''
 
     xml_tags = {} ## Maps tags to functions
 
     def __init__(self, system, xml, item_id = None, track_url=None, state=None, use = 'capa_input'):
+        '''
+        Instantiate a SimpleInput class.  Arguments:
+
+        - system    : I4xSystem instance which provides OS, rendering, and user context 
+        - xml       : Element tree of this Input element
+        - item_id   : id for this input element (assigned by capa_problem.LoncapProblem) - string
+        - track_url : URL used for tracking - string
+        - state     : a dictionary with optional keys: 
+                      * Value
+                      * ID
+                      * Status (answered, unanswered, unsubmitted)
+                      * Feedback (dictionary containing keys for hints, errors, or other 
+                        feedback from previous attempt)
+        - use        :
+        '''
+
         self.xml = xml
         self.tag = xml.tag
-        if not state:
-            state = {}
+        self.system = system
+        if not state: state = {}
+
         ## ID should only come from one place. 
         ## If it comes from multiple, we use state first, XML second, and parameter
         ## third. Since we don't make this guarantee, we can swap this around in 
         ## the future if there's a more logical order. 
-        if item_id:
-            self.id = item_id
-        if xml.get('id'):
-            self.id = xml.get('id')
-        if 'id' in state:
-            self.id = state['id']
-        self.system = system
+        if item_id:       self.id = item_id
+        if xml.get('id'): self.id = xml.get('id')
+        if 'id' in state: self.id = state['id']
 
         self.value = ''
         if 'value' in state:
             self.value = state['value']
 
         self.msg = ''
-        if 'feedback' in state and 'message' in state['feedback']:
-            self.msg = state['feedback']['message']
-
+        feedback = state.get('feedback')
+        if feedback is not None:
+            self.msg = feedback.get('message','')
+            self.hint = feedback.get('hint','')
+            self.hintmode = feedback.get('hintmode',None)
+            
+            # put hint above msg if to be displayed
+            if self.hintmode == 'always':
+                self.msg = self.hint + ('<br/.>' if self.msg else '') + self.msg
+ 
         self.status = 'unanswered'
         if 'status' in state:
             self.status = state['status']

common/lib/capa/util.py

@@ -7,6 +7,11 @@ from calc import evaluator, UndefinedVariable
 def compare_with_tolerance(v1, v2, tol):
     ''' Compare v1 to v2 with maximum tolerance tol
     tol is relative if it ends in %; otherwise, it is absolute
+
+     - v1    :  student result (number)
+     - v2    :  instructor result (number)
+     - tol   :  tolerance (string or number)
+
     '''
     relative = "%" in tol
     if relative: