notify students for NotFoundErrors from capa_module, improve error logging

common/lib/xmodule/xmodule/capa_module.py

@@ -152,6 +152,7 @@ class CapaFields(object):
         scope=Scope.settings
     )
 
+
 class CapaModule(CapaFields, XModule):
     """
     An XModule implementing LonCapa format problems, implemented by way of
@@ -552,6 +553,16 @@ class CapaModule(CapaFields, XModule):
             'ungraded_response': self.handle_ungraded_response
         }
 
+        generic_error_message = (
+            "We're sorry, there was an error with processing your request. "
+            "Please try reloading your page and trying again."
+        )
+
+        not_found_error_message = (
+            "The state of this problem has changed since you loaded this page. "
+            "Please refresh your page."
+        )
+
         if dispatch not in handlers:
             return 'Error'
 
@@ -559,9 +570,14 @@ class CapaModule(CapaFields, XModule):
 
         try:
             result = handlers[dispatch](data)
+
+        except NotFoundError as err:
+            _, _, traceback_obj = sys.exc_info()
+            raise ProcessingError, (not_found_error_message, err), traceback_obj
+
         except Exception as err:
             _, _, traceback_obj = sys.exc_info()
-            raise ProcessingError(err.message, traceback_obj)
+            raise ProcessingError, (generic_error_message, err), traceback_obj
 
         after = self.get_progress()
 
@@ -1125,7 +1141,6 @@ class CapaDescriptor(CapaFields, RawDescriptor):
             problem.rerandomize = "always"
         return problem
 
-
     @property
     def non_editable_metadata_fields(self):
         non_editable_fields = super(CapaDescriptor, self).non_editable_metadata_fields

lms/djangoapps/courseware/module_render.py

@@ -10,7 +10,7 @@ from django.core.cache import cache
 from django.core.exceptions import PermissionDenied
 from django.core.urlresolvers import reverse
 from django.http import Http404
-from django.http import HttpResponse, HttpResponseBadRequest
+from django.http import HttpResponse
 from django.views.decorators.csrf import csrf_exempt
 
 import pyparsing
@@ -38,6 +38,7 @@ from courseware.masquerade import setup_masquerade
 from courseware.model_data import LmsKeyValueStore, LmsUsage, ModelDataCache
 from courseware.models import StudentModule
 from util.sandboxing import can_execute_unsafe_code
+from util.json_request import JsonResponse
 
 log = logging.getLogger(__name__)
 
@@ -509,11 +510,11 @@ def modx_dispatch(request, dispatch, location, course_id):
         log.exception("Module indicating to user that request doesn't exist")
         raise Http404
 
-    # For XModule-specific errors, we respond with 400
-    except ProcessingError:
-        log.warning("Module encountered an error while prcessing AJAX call",
+    # For XModule-specific errors, we log the error and respond with an error message
+    except ProcessingError as err:
+        log.warning("Module encountered an error while processing AJAX call",
                     exc_info=True)
-        return HttpResponseBadRequest()
+        return JsonResponse(object={'success': err.args[0]}, status=200)
 
     # If any other error occurred, re-raise it to trigger a 500 response
     except:

lms/djangoapps/courseware/tests/test_submitting_problems.py

@@ -107,6 +107,15 @@ class TestSubmittingProblems(ModuleStoreTestCase, LoginEnrollmentTestCase):
         resp = self.client.post(modx_url)
         return resp
 
+    def show_question_answer(self, problem_url_name):
+        """
+        Shows the answer to the current student.
+        """
+        problem_location = self.problem_location(problem_url_name)
+        modx_url = self.modx_url(problem_location, 'problem_show')
+        resp = self.client.post(modx_url)
+        return resp
+
     def add_dropdown_to_section(self, section_location, name, num_inputs=2):
         """
         Create and return a dropdown problem.
@@ -131,7 +140,7 @@ class TestSubmittingProblems(ModuleStoreTestCase, LoginEnrollmentTestCase):
             parent_location=section_location,
             category='problem',
             data=prob_xml,
-            metadata={'randomize': 'always'},
+            metadata={'rerandomize': 'always'},
             display_name=name
         )
 
@@ -139,7 +148,7 @@ class TestSubmittingProblems(ModuleStoreTestCase, LoginEnrollmentTestCase):
         self.refresh_course()
         return problem
 
-    def add_graded_section_to_course(self, name, section_format='Homework'):
+    def add_graded_section_to_course(self, name, section_format='Homework', late=False, reset=False, showanswer=False):
         """
         Creates a graded homework section within a chapter and returns the section.
         """
@@ -151,12 +160,44 @@ class TestSubmittingProblems(ModuleStoreTestCase, LoginEnrollmentTestCase):
                 category='chapter'
             )
 
-        section = ItemFactory.create(
-            parent_location=self.chapter.location,
-            display_name=name,
-            category='sequential',
-            metadata={'graded': True, 'format': section_format}
-        )
+        if late:
+            section = ItemFactory.create(
+                parent_location=self.chapter.location,
+                display_name=name,
+                category='sequential',
+                metadata={'graded': True, 'format': section_format, 'due': '2013-05-20T23:30'}
+            )
+        elif reset:
+            section = ItemFactory.create(
+                parent_location=self.chapter.location,
+                display_name=name,
+                category='sequential',
+                rerandomize='always',
+                metadata={
+                    'graded': True,
+                    'format': section_format,
+                }
+            )
+
+        elif showanswer:
+            section = ItemFactory.create(
+                parent_location=self.chapter.location,
+                display_name=name,
+                category='sequential',
+                showanswer='never',
+                metadata={
+                    'graded': True,
+                    'format': section_format,
+                }
+            )
+
+        else:
+            section = ItemFactory.create(
+                parent_location=self.chapter.location,
+                display_name=name,
+                category='sequential',
+                metadata={'graded': True, 'format': section_format}
+            )
 
         # now that we've added the problem and section to the course
         # we fetch the course from the database so the object we are
@@ -257,7 +298,7 @@ class TestCourseGrader(TestSubmittingProblems):
         hw_section = next(section for section in sections_list if section.get('url_name') == hw_url_name)
         return [s.earned for s in hw_section['scores']]
 
-    def basic_setup(self):
+    def basic_setup(self, late=False, reset=False, showanswer=False):
         """
         Set up a simple course for testing basic grading functionality.
         """
@@ -278,7 +319,7 @@ class TestCourseGrader(TestSubmittingProblems):
         self.add_grading_policy(grading_policy)
 
         # set up a simple course with four problems
-        self.homework = self.add_graded_section_to_course('homework')
+        self.homework = self.add_graded_section_to_course('homework', late=late, reset=reset, showanswer=showanswer)
         self.add_dropdown_to_section(self.homework.location, 'p1', 1)
         self.add_dropdown_to_section(self.homework.location, 'p2', 1)
         self.add_dropdown_to_section(self.homework.location, 'p3', 1)
@@ -346,6 +387,41 @@ class TestCourseGrader(TestSubmittingProblems):
         self.add_dropdown_to_section(self.homework3.location, self.hw3_names[0], 1)
         self.add_dropdown_to_section(self.homework3.location, self.hw3_names[1], 1)
 
+    def test_submission_late(self):
+        """Test problem for due date in the past"""
+        self.basic_setup(late=True)
+        resp = self.submit_question_answer('p1', {'2_1': 'Correct'})
+        self.assertEqual(resp.status_code, 200)
+        err_msg = (
+            "The state of this problem has changed since you loaded this page. "
+            "Please refresh your page."
+        )
+        self.assertEqual(json.loads(resp.content).get("success"), err_msg)
+
+    def test_submission_reset(self):
+        """Test problem ProcessingErrors due to resets"""
+        self.basic_setup(reset=True)
+        resp = self.submit_question_answer('p1', {'2_1': 'Correct'})
+        #  submit a second time to draw NotFoundError
+        resp = self.submit_question_answer('p1', {'2_1': 'Correct'})
+        self.assertEqual(resp.status_code, 200)
+        err_msg = (
+            "The state of this problem has changed since you loaded this page. "
+            "Please refresh your page."
+        )
+        self.assertEqual(json.loads(resp.content).get("success"), err_msg)
+
+    def test_submission_show_answer(self):
+        """Test problem for ProcessingErrors due to showing answer"""
+        self.basic_setup(showanswer=True)
+        resp = self.show_question_answer('p1')
+        self.assertEqual(resp.status_code, 200)
+        err_msg = (
+            "The state of this problem has changed since you loaded this page. "
+            "Please refresh your page."
+        )
+        self.assertEqual(json.loads(resp.content).get("success"), err_msg)
+
     def test_none_grade(self):
         """
         Check grade is 0 to begin with.