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, 102 insertions, 0 deletions

diff --git a/exam/models.py b/exam/models.py
new file mode 100644
index 0000000..247b362
--- /dev/null
+++ b/exam/models.py
@@ -0,0 +1,102 @@
+from django.db import models
+from django.contrib.auth.models import User
+
+# Create your models here.
+
+class Profile(models.Model):
+    """Profile for a user to store roll number etc."""
+    user = models.ForeignKey(User)
+    roll_number = models.CharField(max_length=20)
+
+class Question(models.Model):
+    """A question in the database."""
+    # An optional one-line summary of the question.
+    summary = models.CharField(max_length=256)
+    # The question text.
+    question = models.TextField()
+    
+    # Number of points for the question.
+    points = models.IntegerField()
+    
+    # Test cases for the question in the form of code that is run.
+    # This is simple Python code.
+    test = models.TextField()
+    
+    def __unicode__(self):
+        return self.summary
+    
+
+class Answer(models.Model):
+    """Answers submitted by users.
+    """
+    question = models.ForeignKey(Question)
+    # The last answer submitted by the user.
+    answer = models.TextField()
+    attempts = models.IntegerField()
+    
+    # Is the question correct.
+    correct = models.BooleanField()
+    # Marks obtained.
+    marks = models.IntegerField()
+    
+    def __unicode__(self):
+        return self.answer
+    
+class Quiz(models.Model):
+    """A quiz for a student.
+    """
+    user = models.ForeignKey(User)
+    user_ip = models.CharField(max_length=15)
+    key = models.CharField(max_length=10)
+    questions = models.CharField(max_length=128)
+    questions_answered = models.CharField(max_length=128)
+    
+    def current_question(self):
+        """Returns the current active question to display."""
+        qs = self.questions.split('|')
+        if len(qs) > 0:
+            return qs[0]
+        else:
+            return ''
+            
+    def questions_left(self):
+        """Returns the number of questions left."""
+        qs = self.questions
+        if len(qs) == 0:
+            return 0
+        else:
+            return qs.count('|') + 1
+            
+    def answered_question(self, question_id):
+        """Removes the question from the list of questions and returns
+        the next."""
+        qa = self.questions_answered
+        if len(qa) > 0:
+            self.questions_answered = '|'.join([qa, str(question_id)])
+        else:
+            self.questions_answered = str(question_id)
+        qs = self.questions.split('|')
+        qs.remove(unicode(question_id))
+        self.questions = '|'.join(qs)
+        self.save()
+        if len(qs) == 0:
+            return ''
+        else:
+            return qs[0]
+            
+    def skip(self):
+        """Skip the current question and return the next available question."""
+        qs = self.questions.split('|')
+        if len(qs) == 0:
+            return ''
+        else:
+            # Put head at the end.
+            head = qs.pop(0)
+            qs.append(head)
+            self.questions = '|'.join(qs)
+            self.save()
+            return qs[0]
+    
+    def __unicode__(self):
+        u = self.user
+        return u'Quiz for {0} {1}'.format(u.first_name, u.last_name)