ENH: Cleanup and adding error/comments for answers

Adding error and marks field to each answer.  Adding a new comment field
to the question paper and also a profile field for convenience.
Changing the views, templates and dump scripts to use the models rather
than Python code.  This cleans things up a lot more.  The user data
logged and printed is also way more comprehensive, paving the way for
easy online grading as well in the next phase of changes.

4 files changed, 133 insertions, 157 deletions

diff --git a/exam/management/commands/dump_user_data.py b/exam/management/commands/dump_user_data.py
index f14e144..f081565 100644
--- a/exam/management/commands/dump_user_data.py
+++ b/exam/management/commands/dump_user_data.py
@@ -8,34 +8,45 @@ from exam.models import User
 
 data_template = Template('''\
 ===============================================================================
-Data for {{ user_data.name.title }} ({{ user_data.username }})
+Data for {{ data.user.get_full_name.title }} ({{ data.user.username }})
 
-Name: {{ user_data.name.title }}
-Username: {{ user_data.username }}
-Roll number: {{ user_data.rollno }}
-Email: {{ user_data.email }}
-Position: {{ user_data.position }}
-Department: {{ user_data.department }}
-Institute: {{ user_data.institute }}
-Date joined: {{ user_data.date_joined }}
-Last login: {{ user_data.last_login }}
-{% for paper in user_data.papers %}
-Paper: {{ paper.name }}
------------------------------------------
-Total marks: {{ paper.total }}
-Questions correctly answered: {{ paper.answered }}
-Total attempts at questions: {{ paper.attempts }}
-Start time: {{ paper.start_time }} 
-User IP address: {{ paper.user_ip }} 
-{% if paper.answers %}
+Name: {{ data.user.get_full_name.title }}
+Username: {{ data.user.username }}
+{% if data.profile %}\
+Roll number: {{ data.profile.roll_number }}
+Position: {{ data.profile.position }}
+Department: {{ data.profile.department }}
+Institute: {{ data.profile.institute }}
+{% endif %}\
+Email: {{ data.user.email }}
+Date joined: {{ data.user.date_joined }}
+Last login: {{ data.user.last_login }} 
+{% for paper in data.papers %}
+Paper: {{ paper.quiz.description }}
+---------------------------------------
+Marks obtained: {{ paper.get_total_marks }}
+Questions correctly answered: {{ paper.get_answered_str }}
+Total attempts at questions: {{ paper.answers.count }}
+Start time: {{ paper.start_time }}
+User IP address: {{ paper.user_ip }}
+{% if paper.answers.count %}
 Answers
 -------
-{% for question, answer in paper.answers.items %}
-Question: {{ question }}
-{{ answer|safe }}
-{% endfor %} \
-{% endif %} {# if paper.answers #} \
-{% endfor %} {# for paper in user_data.papers #}
+{% for question, answers in paper.get_question_answers.items %}
+Question: {{ question.id }}. {{ question.summary }} (Points: {{ question.points }})
+{% for answer in answers %}\
+###############################################################################
+{{ answer.answer|safe }}
+# Autocheck: {{ answer.error|safe }}
+# Marks: {{ answer.marks }}
+{% endfor %}{# for answer in answers #}\
+{% endfor %}{# for question, answers ... #}\
+
+Teacher comments
+-----------------
+{{ paper.comments|default:"None" }}
+{% endif %}{# if paper.answers.count #}\
+{% endfor %}{# for paper in data.papers #}
 ''')
 
 
@@ -60,7 +71,7 @@ def dump_user_data(unames, stdout):
 
     for user in users:
         data = get_user_data(user.username)
-        context = Context({'user_data': data})
+        context = Context({'data': data})
         result = data_template.render(context)
         stdout.write(result)
 
diff --git a/exam/management/commands/results2csv.py b/exam/management/commands/results2csv.py
index f1da1a8..2993745 100644
--- a/exam/management/commands/results2csv.py
+++ b/exam/management/commands/results2csv.py
@@ -7,16 +7,22 @@ from django.core.management.base import BaseCommand
 from django.template import Template, Context
 
 # Local imports.
-from exam.views import get_quiz_data
-from exam.models import Quiz
+from exam.models import Quiz, QuestionPaper
 
 result_template = Template('''\
-"name","username","rollno","email","answered","total","attempts","position","department","institute"
-{% for paper in paper_list %}\
-"{{ paper.name }}","{{ paper.username }}","{{ paper.rollno }}",\
-"{{ paper.email }}","{{ paper.answered }}",{{ paper.total }},\
-{{ paper.attempts }},"{{ paper.position }}",\
-"{{ paper.department }}","{{ paper.institute }}"
+"name","username","rollno","email","answered","total","attempts","position",\
+"department","institute"
+{% for paper in papers %}\
+"{{ paper.user.get_full_name.title }}",\
+"{{ paper.user.username }}",\
+"{{ paper.profile.roll_number }}",\
+"{{ paper.user.email }}",\
+"{{ paper.get_answered_str }}",\
+{{ paper.get_total_marks }},\
+{{ paper.answers.count }},\
+"{{ paper.profile.position }}",\
+"{{ paper.profile.department }}",\
+"{{ paper.profile.institute }}"
 {% endfor %}\
 ''')
 
@@ -39,12 +45,13 @@ def results2csv(filename, stdout):
     else:
         quiz = qs[0]
 
-    paper_list = get_quiz_data(quiz.id)
+    papers = QuestionPaper.objects.filter(quiz=quiz,
+                                          user__profile__isnull=False)
     stdout.write("Saving results of %s to %s ... "%(quiz.description,
                                                     basename(filename)))
     # Render the data and write it out.
     f = open(filename, 'w')
-    context = Context({'paper_list': paper_list})
+    context = Context({'papers': papers})
     f.write(result_template.render(context))
     f.close()
 
diff --git a/exam/models.py b/exam/models.py
index fb06576..d433c7c 100644
--- a/exam/models.py
+++ b/exam/models.py
@@ -5,7 +5,7 @@ from django.contrib.auth.models import User
 ################################################################################
 class Profile(models.Model):
     """Profile for a user to store roll number and other details."""
-    user = models.ForeignKey(User)
+    user = models.OneToOneField(User)
     roll_number = models.CharField(max_length=20)
     institute = models.CharField(max_length=128)
     department = models.CharField(max_length=64)
@@ -44,8 +44,15 @@ class Answer(models.Model):
     # The question for which we are an answer.
     question = models.ForeignKey(Question)
     
-    # The last answer submitted by the user.
+    # The answer submitted by the user.
     answer = models.TextField()
+
+    # Error message when auto-checking the answer.
+    error = models.TextField()
+
+    # Marks obtained for the answer.  This can be changed by the teacher if the
+    # grading is manual.
+    marks = models.FloatField(default=0.0)
     
     # Is the answer correct.
     correct = models.BooleanField(default=False)
@@ -86,6 +93,10 @@ class QuestionPaper(models.Model):
     """
     # The user taking this question paper.
     user = models.ForeignKey(User)
+
+    # The user's profile, we store a reference to make it easier to access the
+    # data.
+    profile = models.ForeignKey(Profile)
     
     # The Quiz to which this question paper is attached to.
     quiz = models.ForeignKey(Quiz)
@@ -108,6 +119,9 @@ class QuestionPaper(models.Model):
     
     # All the submitted answers.
     answers = models.ManyToManyField(Answer)
+
+    # Teacher comments on the question paper.
+    comments = models.TextField()
     
     def current_question(self):
         """Returns the current active question to display."""
@@ -125,7 +139,7 @@ class QuestionPaper(models.Model):
         else:
             return qs.count('|') + 1
             
-    def answered_question(self, question_id):
+    def completed_question(self, question_id):
         """Removes the question from the list of questions and returns
         the next."""
         qa = self.questions_answered
@@ -141,7 +155,7 @@ class QuestionPaper(models.Model):
             return ''
         else:
             return qs[0]
-            
+
     def skip(self):
         """Skip the current question and return the next available question."""
         qs = self.questions.split('|')
@@ -166,6 +180,29 @@ class QuestionPaper(models.Model):
         total = self.quiz.duration*60.0
         remain = max(total - secs, 0)
         return int(remain)
+
+    def get_answered_str(self):
+        """Returns the answered questions, sorted and as a nice string."""
+        qa = self.questions_answered.split('|')
+        answered = ', '.join(sorted(qa))
+        return answered if answered else 'None'
+
+    def get_total_marks(self):
+        """Returns the total marks earned by student for this paper."""
+        return sum([x.marks for x in self.answers.filter(marks__gt=0.0)])
+
+    def get_question_answers(self):
+        """Return a dictionary with keys as questions and a list of the corresponding
+        answers.
+        """
+        q_a = {}
+        for answer in self.answers.all():
+            question = answer.question
+            if question in q_a:
+                q_a[question].append(answer)
+            else:
+                q_a[question] = [answer]
+        return q_a
     
     def __unicode__(self):
         u = self.user
diff --git a/exam/views.py b/exam/views.py
index b880c4d..bafd0be 100644
--- a/exam/views.py
+++ b/exam/views.py
@@ -121,7 +121,12 @@ def start(request):
     except QuestionPaper.DoesNotExist:
         ip = request.META['REMOTE_ADDR']
         key = gen_key(10)
-        new_paper = QuestionPaper(user=user, user_ip=ip, key=key, quiz=quiz)
+        try:
+            profile = user.get_profile()
+        except Profile.DoesNotExist:
+            profile = None
+        new_paper = QuestionPaper(user=user, user_ip=ip, key=key, 
+                                  quiz=quiz, profile=profile)
         new_paper.start_time = datetime.datetime.now()
         
         # Make user directory.
@@ -199,11 +204,14 @@ def check(request, q_id):
     # running as nobody.
     user_dir = get_user_dir(user)
     success, err_msg = python_server.run_code(answer, question.test, user_dir)
-    
+    new_answer.error = err_msg
+
     if success:
-        # Note the success and save it.
+        # Note the success and save it along with the marks.
         new_answer.correct = success
-        new_answer.save()
+        new_answer.marks = question.points
+
+    new_answer.save()
 
     ci = RequestContext(request)
     if not success:
@@ -221,7 +229,7 @@ def check(request, q_id):
         return my_render_to_response('exam/question.html', context, 
                                      context_instance=ci)
     else:
-        next_q = paper.answered_question(question.id)
+        next_q = paper.completed_question(question.id)
         return show_question(request, next_q)
         
 def quit(request):
@@ -241,151 +249,64 @@ def complete(request, reason=None):
         return my_render_to_response('exam/complete.html', context)
     else:
         return my_redirect('/exam/')
-        
-def get_quiz_data(quiz_id):
-    """Convenience function to get all quiz results.  This is used by other
-    functions.  Returns a list containing one dictionary for each question paper
-    of the quiz.  The dictionary contains the necessary data.
-    """
-    try:
-        quiz = Quiz.objects.get(id=quiz_id)
-    except Quiz.DoesNotExist:
-        q_papers = []
-    else:
-        q_papers = QuestionPaper.objects.filter(quiz=quiz)
-        questions = Question.objects.all()
-        # Mapping from question id to points
-        marks = dict( ( (q.id, q.points) for q in questions) )
-    
-    paper_list = []    
-    for q_paper in q_papers:
-        paper = {}
-        user = q_paper.user
-        try:
-            profile = Profile.objects.get(user=user)
-        except Profile.DoesNotExist:
-            # Admin user may have a paper by accident but no profile.
-            continue
-        paper['name'] = user.get_full_name()
-        paper['username'] = user.username
-        paper['rollno'] = str(profile.roll_number)
-        paper['institute'] = str(profile.institute)
-        paper['email'] = user.email
-        qa = q_paper.questions_answered.split('|')
-        answered = ', '.join(sorted(qa))
-        paper['answered'] = answered if answered else 'None'
-        paper['attempts'] = q_paper.answers.count()
-        total = sum( [marks[int(id)] for id in qa if id] )
-        paper['total'] = total
-        paper_list.append(paper)
-        
-    return paper_list
-   
+
 def monitor(request, quiz_id=None):
     """Monitor the progress of the papers taken so far."""
     user = request.user
     if not user.is_authenticated() and not user.is_staff:
         raise Http404('You are not allowed to view this page!')
-        
+
     if quiz_id is None:
         quizzes = Quiz.objects.all()
-        quiz_data = {}
-        for quiz in quizzes:
-            quiz_data[quiz.id] = quiz.description
-        context = {'paper_list': [], 
-                   'quiz_name': '', 
-                   'quiz_data':quiz_data}
+        context = {'papers': [], 
+                   'quiz': None, 
+                   'quizzes':quizzes}
         return my_render_to_response('exam/monitor.html', context,
                                     context_instance=RequestContext(request)) 
     # quiz_id is not None.
     try:
         quiz = Quiz.objects.get(id=quiz_id)
     except Quiz.DoesNotExist:
-        quiz = None
-
-    quiz_data = {}
-    paper_list = get_quiz_data(quiz_id)
-
-    if quiz is None:
-        quiz_name = 'No active quiz'
-    elif len(quiz.description) > 0:
-        quiz_name = quiz.description
+        papers = []
     else:
-        quiz_name = 'Quiz'
-        
-    paper_list.sort(cmp=lambda x, y: cmp(x['total'], y['total']), 
-                   reverse=True)
+        papers = QuestionPaper.objects.filter(quiz=quiz,
+                                              user__profile__isnull=False)
 
-    context = {'paper_list': paper_list, 'quiz_name': quiz_name}
+    sorted(papers, 
+           cmp=lambda x, y: cmp(x.get_total_marks(), y.get_total_marks()), 
+           reverse=True)
+
+    context = {'papers': papers, 'quiz': quiz, 'quizzes': None}
     return my_render_to_response('exam/monitor.html', context,
                                  context_instance=RequestContext(request)) 
-                                 
+
 def get_user_data(username):
     """For a given username, this returns a dictionary of important data
     related to the user including all the user's answers submitted.
     """
-    try:
-        user = User.objects.get(username=username)
-    except User.DoesNotExist:
-        q_papers = []
-    else:
-        q_papers = QuestionPaper.objects.filter(user=user)
-        questions = Question.objects.all()
-        # Mapping from question id to points
-        marks = dict( ( (q.id, q.points) for q in questions) )
+    user = User.objects.get(username=username)
+    papers = QuestionPaper.objects.filter(user=user)
 
     data = {}
     try:
-        profile = Profile.objects.get(user=user)
+        profile = user.get_profile()
     except Profile.DoesNotExist:
         # Admin user may have a paper by accident but no profile.
         profile = None
-    data['username'] = user.username
-    data['email'] = user.email
-    data['rollno'] = profile.roll_number if profile else ''
-    data['name'] = user.get_full_name()
-    data['institute'] = profile.institute if profile else ''
-    data['department'] = profile.department if profile else ''
-    data['position'] = profile.position if profile else ''
-    data['name'] = user.get_full_name()
-    data['date_joined'] = str(user.date_joined)
-    data['last_login'] = str(user.last_login)
-    papers = []
-    for q_paper in q_papers:
-        paper = {}
-        paper['name'] = q_paper.quiz.description
-        qa = q_paper.questions_answered.split('|')
-        answered = ', '.join(sorted(qa))
-        paper['answered'] = answered if answered else 'None'
-        paper['attempts'] = q_paper.answers.count()
-        total = sum( [marks[int(id)] for id in qa if id] )
-        paper['total'] = total
-        paper['user_ip'] = q_paper.user_ip
-        paper['start_time'] = str(q_paper.start_time)
-        answers = {}
-        for answer in q_paper.answers.all():
-            question = answer.question
-            qs = '%d. %s'%(question.id, question.summary)
-            code = '#'*80 + '\n' + str(answer.answer) + '\n'
-            if qs in answers:
-                answers[qs] += code
-            else:
-                answers[qs] = code
-        paper['answers'] = answers
-        papers.append(paper)
-    data['papers'] = papers
+    data['user'] = user
+    data['profile'] = profile
+    data['papers'] = papers 
     return data
-    
 
 def user_data(request, username):
     """Render user data."""
     current_user = request.user
     if not current_user.is_authenticated() and not current_user.is_staff:
         raise Http404('You are not allowed to view this page!')
-        
+
     data = get_user_data(username)
-        
-    context = {'user_data': data}
+
+    context = {'data': data}
     return my_render_to_response('exam/user_data.html', context,
-                                 context_instance=RequestContext(request)) 
-    
+                                 context_instance=RequestContext(request))
+