NEW: First cut of exam app.

This application allows us to create questions via the admin interface.
The questions are proper programming questions and one enters test cases
for each question.  The user logs in and submits the answer which is
checked.  The app is rather simple now but does work.

1 files changed, 150 insertions, 0 deletions

diff --git a/exam/views.py b/exam/views.py
new file mode 100644
index 0000000..10d6c9a
--- /dev/null
+++ b/exam/views.py
@@ -0,0 +1,150 @@
+import random
+import sys
+import traceback
+import string
+
+from django.db import IntegrityError
+from django.contrib.auth.models import User
+from django.contrib.auth import login, logout, authenticate
+from django.shortcuts import render_to_response, get_object_or_404, redirect
+from django.template import RequestContext
+from exam.models import Question, Quiz, Profile
+from exam.forms import UserRegisterForm
+
+def gen_key(no_of_chars):
+    allowed_chars = string.digits+string.uppercase
+    return ''.join([random.choice(allowed_chars) for i in range(no_of_chars)])
+
+def index_old(request):
+    """The start page.
+    """
+    question_list = Question.objects.all()
+    context = {'question_list': question_list}
+    return render_to_response('exam/index.html', context)
+    
+def index(request):
+    """The start page.
+    """
+    # Largely copied from Nishanth's quiz app.
+    user = request.user
+    if user.is_authenticated():
+        return redirect("/exam/start/")
+    else:
+        try:
+            ip = request.META['REMOTE_ADDR']
+            Quiz.objects.get(user_ip=ip)
+            return redirect("/exam/complete")
+        except Quiz.DoesNotExist:
+            pass
+
+    if request.method == "POST":
+        form = UserRegisterForm(request.POST)
+        if form.is_valid():
+            data = form.cleaned_data
+
+            while True:
+                try:
+                    username = gen_key(20)
+                    new_user = User.objects.create_user(username, "temp@temp.com", "123")
+                    break
+                except IntegrityError:
+                    pass
+
+            new_user.first_name = data['first_name']
+            new_user.last_name = data['last_name']
+            new_user.save()
+
+            new_profile = Profile(user=new_user)
+            new_profile.roll_number = data['roll_number']
+            new_profile.save()
+
+            user = authenticate(username=username, password="123")
+            login(request, user)
+            return redirect("/exam/start/")
+
+        else:
+            return render_to_response('exam/register.html',{'form':form},
+                context_instance=RequestContext(request))
+    else:
+        form = UserRegisterForm()
+        return render_to_response('exam/register.html',{'form':form},
+             context_instance=RequestContext(request))
+
+def show_question(request, q_id):
+    if len(q_id) == 0:
+        return redirect("/exam/complete")
+    else:
+        return question(request, q_id)
+    
+def start(request):
+    user = request.user
+    try:
+        old_quiz = Quiz.objects.get(user=user)
+        q = old_quiz.current_question()
+        return show_question(request, q)
+    except Quiz.DoesNotExist:
+        ip = request.META['REMOTE_ADDR']
+        key = gen_key(10)
+        new_quiz = Quiz(user=user, user_ip=ip, key=key)
+
+        questions = [ str(_.id) for _ in Question.objects.all() ]
+        random.shuffle(questions)
+        questions = questions[:3]
+        
+        new_quiz.questions = "|".join(questions)
+        new_quiz.save()
+        q = new_quiz.current_question()
+
+        return show_question(request, q)
+
+def question(request, q_id):
+    q = get_object_or_404(Question, pk=q_id)
+    try:
+        quiz = Quiz.objects.get(user=request.user)
+    except Quiz.DoesNotExist:
+        redirect('/exam/start')
+    context = {'question': q, 'quiz': quiz}
+    ci = RequestContext(request)
+    return render_to_response('exam/question.html', context, 
+                              context_instance=ci)
+
+def test_answer(func_code, test_code):
+    exec func_code
+    exec test_code
+
+def check(request, q_id):
+    user = request.user
+    question = get_object_or_404(Question, pk=q_id)
+    quiz = Quiz.objects.get(user=user)
+    answer = request.POST.get('answer')
+    skip = request.POST.get('skip', None)
+    
+    if skip is not None:
+        next_q = quiz.skip()
+        return show_question(request, next_q)
+        
+    # Otherwise we were asked to check.
+    retry = True
+    try:
+        test_answer(answer, question.test)
+    except:
+        type, value, tb = sys.exc_info()
+        info = traceback.extract_tb(tb)
+        fname, lineno, func, text = info[-1]
+        err = "{0}: {1} In code: {2}".format(type.__name__, str(value), text)
+    else:
+        retry = False
+        err = 'Correct answer'
+        
+    ci = RequestContext(request)
+    if retry:
+        context = {'question': question, 'error_message': err}
+        return render_to_response('exam/question.html', context, 
+                                  context_instance=ci)
+    else:
+        next_q = quiz.answered_question(question.id)
+        return show_question(request, next_q)
+
+def complete(request):
+    return render_to_response('exam/complete.html')
+    
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