Models modified.

QuestionPaper model modified for generating random questions.
Added language field to Question model.
Removed tags from Quiz model.
Template and javascript for Add and Edit questions modified.
Added test cases for models.

1 files changed, 107 insertions, 33 deletions

diff --git a/testapp/exam/models.py b/testapp/exam/models.py
index 758091f..ca53b2c 100644
--- a/testapp/exam/models.py
+++ b/testapp/exam/models.py
@@ -1,12 +1,12 @@
 import datetime
+from random import sample
 from django.db import models
 from django.contrib.auth.models import User
 from taggit_autocomplete_modified.managers import TaggableManagerAutocomplete\
 as TaggableManager
-from django.http import HttpResponse
-################################################################################
 
 
+###############################################################################
 class Profile(models.Model):
     """Profile for a user to store roll number and other details."""
     user = models.OneToOneField(User)
@@ -16,25 +16,30 @@ class Profile(models.Model):
     position = models.CharField(max_length=64)
 
 
-QUESTION_TYPE_CHOICES = (
+QUESTION_LANGUAGE_CHOICES = (
         ("python", "Python"),
         ("bash", "Bash"),
-        ("mcq", "MultipleChoice"),
         ("C", "C Language"),
         ("C++", "C++ Language"),
         ("java", "Java Language"),
         ("scilab", "Scilab"),
+                            )
+
+
+QUESTION_TYPE_CHOICES = (
+        ("mcq", "Multiple Choice"),
+        ("code", "Code"),
                         )
-################################################################################
 
 
+###############################################################################
 class Question(models.Model):
-    """A question in the database."""
+    """A question details in the database."""
 
     # A one-line summary of the question.
     summary = models.CharField(max_length=256)
 
-    # The question text, should be valid HTML.
+    # The question text, should be a valid HTML.
     description = models.TextField()
 
     # Number of points for the question.
@@ -43,31 +48,35 @@ class Question(models.Model):
     # Test cases for the question in the form of code that is run.
     test = models.TextField(blank=True)
 
-    # Any multiple choice options.  Place one option per line.
+    # Any multiple choice options. Place one option per line.
     options = models.TextField(blank=True)
 
+    # The language for question.
+    language = models.CharField(max_length=24,
+                                choices=QUESTION_LANGUAGE_CHOICES)
+
     # The type of question.
     type = models.CharField(max_length=24, choices=QUESTION_TYPE_CHOICES)
 
-    # Is this question active or not.  If it is inactive it will not be used
+    # Is this question active or not. If it is inactive it will not be used
     # when creating a QuestionPaper.
     active = models.BooleanField(default=True)
 
-    #Code Snippet
+    # Code Snippet
     snippet = models.CharField(max_length=256)
 
-    #Tags for the Question.
+    # Tags for the Question.
     tags = TaggableManager()
 
     def __unicode__(self):
         return self.summary
 
 
-################################################################################
+###############################################################################
 class Answer(models.Model):
-    """Answers submitted by users.
-    """
-    # The question for which we are an answer.
+    """Answers submitted by the users."""
+
+    # The question for which user answers.
     question = models.ForeignKey(Question)
 
     # The answer submitted by the user.
@@ -76,7 +85,7 @@ class Answer(models.Model):
     # Error message when auto-checking the answer.
     error = models.TextField()
 
-    # Marks obtained for the answer.  This can be changed by the teacher if the
+    # Marks obtained for the answer. This can be changed by the teacher if the
     # grading is manual.
     marks = models.FloatField(default=0.0)
 
@@ -87,44 +96,103 @@ class Answer(models.Model):
         return self.answer
 
 
-################################################################################
+###############################################################################
 class Quiz(models.Model):
     """A quiz that students will participate in. One can think of this
     as the "examination" event.
     """
 
-    # The starting/ending date of the quiz.
+    # The start date of the quiz.
     start_date = models.DateField("Date of the quiz")
 
     # This is always in minutes.
     duration = models.IntegerField("Duration of quiz in minutes", default=20)
 
-    # Is the quiz active.  The admin should deactivate the quiz once it is
+    # Is the quiz active. The admin should deactivate the quiz once it is
     # complete.
     active = models.BooleanField(default=True)
 
     # Description of quiz.
     description = models.CharField(max_length=256)
 
-    #Tags for the Quiz.
-    tags = TaggableManager()
-
     class Meta:
         verbose_name_plural = "Quizzes"
 
     def __unicode__(self):
         desc = self.description or 'Quiz'
-        return '%s: on %s for %d minutes' % (desc, self.start_date, self.duration)
+        return '%s: on %s for %d minutes' % (desc, self.start_date,
+                                             self.duration)
 
 
-################################################################################
+###############################################################################
 class QuestionPaper(models.Model):
+    """Question paper stores the detail of the questions."""
+
+    # Question paper belongs to a particular quiz.
     quiz = models.ForeignKey(Quiz)
-    questions = models.ManyToManyField(Question)
+
+    # Questions that will be mandatory in the quiz.
+    fixed_questions = models.ManyToManyField(Question)
+
+    # Questions that will be fetched randomly from the Question Set.
+    random_questions = models.ManyToManyField("QuestionSet")
+
+    # Total marks for the question paper.
     total_marks = models.FloatField()
 
+    def get_total_marks(self):
+        """ Returns the total marks for the Question Paper"""
+        marks = 0.0
+        questions = self.fixed_questions.all()
+        for question in questions:
+            marks += question.points
+        for question_set in self.random_questions.all():
+            marks += question_set.marks * question_set.num_questions
+        return marks
+
+    def _get_questions_for_answerpaper(self):
+        """ Returns fixed and random questions for the answer paper"""
+        questions = []
+        questions = list(self.fixed_questions.all())
+        for question_set in self.random_questions.all():
+            questions += question_set.get_random_questions()
+        return questions
+
+    def make_answerpaper(self, user, profile, ip):
+        """Creates an  answer paper for the user to attempt the quiz"""
+        ans_paper = AnswerPaper(user=user, profile=profile, user_ip=ip)
+        ans_paper.start_time = datetime.datetime.now()
+        ans_paper.end_time = ans_paper.start_time \
+                             + datetime.timedelta(minutes=self.quiz.duration)
+        ans_paper.question_paper = self
+        questions = self._get_questions_for_answerpaper()
+        question_ids = [str(_.id) for _ in questions]
+        ans_paper.questions = "|".join(question_ids)
+        ans_paper.save()
+        return ans_paper
+
+
+###############################################################################
+class QuestionSet(models.Model):
+    """Question set contains set of questions from which random questions
+       will be selected for the quiz.
+    """
+
+    # Marks of each question of a particular Question Set
+    marks = models.FloatField()
+
+    # Number of questions to be fetched for the quiz.
+    num_questions = models.IntegerField()
+
+    # Set of questions for sampling randomly.
+    questions = models.ManyToManyField(Question)
+
+    def get_random_questions(self):
+        """ Returns random questions from set of questions"""
+        return sample(self.questions.all(), self.num_questions)
 
-################################################################################
+
+###############################################################################
 class AnswerPaper(models.Model):
     """A answer paper for a student -- one per student typically.
     """
@@ -135,7 +203,8 @@ class AnswerPaper(models.Model):
     # data.
     profile = models.ForeignKey(Profile)
 
-    # All questions that remains to attempt to perticular Student
+    # All questions that are left to attempt for a particular Student
+    # (a list of ids separated by '|')
     questions = models.CharField(max_length=128)
 
     # The Quiz to which this question paper is attached to.
@@ -176,8 +245,10 @@ class AnswerPaper(models.Model):
             return qs.count('|') + 1
 
     def completed_question(self, question_id):
-        """Removes the question from the list of questions and returns
-the next."""
+        """
+            Removes the completed question from the list of questions and
+            returns the next question.
+        """
         qa = self.questions_answered
         if len(qa) > 0:
             self.questions_answered = '|'.join([qa, str(question_id)])
@@ -193,7 +264,9 @@ the next."""
             return qs[0]
 
     def skip(self):
-        """Skip the current question and return the next available question."""
+        """
+            Skips the current question and returns the next available question.
+        """
         qs = self.questions.split('|')
         if len(qs) == 0:
             return ''
@@ -223,13 +296,14 @@ the next."""
         answered = ', '.join(sorted(qa))
         return answered if answered else 'None'
 
-    def get_total_marks(self):
+    def get_marks_obtained(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.
+        """
+            Return a dictionary with keys as questions and a list of the
+            corresponding answers.
         """
         q_a = {}
         for answer in self.answers.all():