Bugfix conjunctavgsurvey: submission needs assignment

Also rewrote the code to be more readable (and literate).

src/canvaslms/grades/conjunctavgsurvey.nw

@@ -65,7 +65,8 @@ def summarize(user, assignments_list):
   for assignment in assignments_list:
     try:
       submission = assignment.get_submission(user,
-                                            include=["submission_history"])
+                                             include=["submission_history"])
+      submission.assignment = assignment
     except ResourceDoesNotExist:
       pf_grades.append("F")
       continue
@@ -76,34 +77,73 @@ def summarize(user, assignments_list):
     if grade is None:
       grade = "F"
 
-    if grade in "ABCDE":
-      a2e_grades.append(grade)
-    elif grade in "PF":
-      pf_grades.append(grade)
-    elif grade == "Fx":
-      pf_grades.append("F")
-    else:
-      pf_grades.append("P")
+    <<add grade to the appropriate list>>
+    <<add grade date to the list [[dates]]>>
 
-    grade_date = submission.submitted_at or submission.graded_at
+  <<let [[final_grade]] be the final grade>>
+  <<let [[final_date]] be the final date>>
 
-    if grade_date:
-      grade_date = dt.date.fromisoformat(grade_date.split("T")[0])
-      dates.append(grade_date)
+  <<check that the data is correct>>
 
-  if all(map(lambda x: x == "P", pf_grades)):
-    final_grade = "P"
-    if a2e_grades:
-      final_grade = a2e_average(a2e_grades)
+  return (final_grade, final_date, graders)
+@
 
-  if dates:
-    final_date = max(dates)
-  else:
-    final_date = None
-    final_grade = None
+We look at the grade and add it to the appropriate list.
+The grade Fx is treated as an F.
+It's the only grade that should be more than one letter.
+<<add grade to the appropriate list>>=
+if grade in "ABCDE":
+  a2e_grades.append(grade)
+elif grade in "PF":
+  pf_grades.append(grade)
+elif grade == "Fx":
+  pf_grades.append("F")
+else:
+  pf_grades.append("P")
+@
 
-  if len(dates) < len(pf_grades) + len(a2e_grades):
-    final_grade = "F"
+When we check, we check that all the P/F grades are P.
+If that's the case, we can compute the average of the A--E grades---if there 
+are any.
+If there are no A--E grades, the final grade is P.
+<<let [[final_grade]] be the final grade>>=
+if all(map(lambda x: x == "P", pf_grades)):
+  final_grade = "P"
+  if a2e_grades:
+    final_grade = a2e_average(a2e_grades)
+else:
+  final_grade = "F"
+@
 
-  return (final_grade, final_date, graders)
+When it comes to the date, we want primarily the submission date.
+If there is no submission date, we use the grade date.
+(However, when we require the student to present their work, we should probably 
+use the grade date as that best represents the date of presenting.)
+<<add grade date to the list [[dates]]>>
+grade_date = submission.submitted_at or submission.graded_at
+
+if grade_date:
+  grade_date = dt.date.fromisoformat(grade_date.split("T")[0])
+  dates.append(grade_date)
+@
+
+When we check the dates, we want the final date to be the most recent date.
+If there are no dates, the student hasn't done anything, then we set the final 
+grade (and date) to [[None]] instead of F.
+<<let [[final_date]] be the final date>>=
+if dates:
+  final_date = max(dates)
+else:
+  final_date = None
+  final_grade = None
 @
+
+Finally, as a check, we can check that the number of dates and number of grades 
+are the same.
+Otherwise, they have passed everything they have done, but simply not done some 
+assignment.
+<<check that the data is correct>>=
+if len(dates) < len(pf_grades) + len(a2e_grades):
+  final_grade = "F"
+@
+