Improving models for a Django quiz

Question

I'm working on a little django quiz taking app. Currently I'm making it's models. So far I've got Quiz, Question, Answer, and Response designed as follows:

from django.db import models
from npage.mixins import TranslatedModelMixin
from django.contrib.auth.models import User
# Create your models here.
class Quiz(models.Model):
 title = models.CharField(max_length=60,blank=False,)
 # show_feedback = models.BooleanField(blank=False,default=True,help_text="Correct answer is shown after question.",)
 class Meta:
 verbose_name = "Quiz"
 verbose_name_plural = "Quizzes"
 def __unicode__(self):
 return self.title
class Question(models.Model, TranslatedModelMixin):
 quiz = models.ManyToManyField(Quiz, blank=True, )
 content = models.CharField(max_length=1000, blank=False, help_text="Enter the question text that you want displayed",verbose_name='Question',)
 es_content = models.CharField(max_length=1000, blank=True, help_text="Enter the question text that you want displayed",verbose_name='Question',)
 type = models.CharField(max_length=8, choices=TYPES, default='radio')
 is_scoreable = models.BooleanField(default=True, help_text="Will the answer to this question be scored?")
 # idea
 # tags = models.CharField(max_length=1000, blank=False, help_text="Enter some text to help you find this question to add it to quizzes later on.",verbose_name='Question',)
 feedback = models.TextField(max_length=2000,blank=True,help_text="Explanation to be shown after the question has been answered.",verbose_name='Explanation',)
 es_feedback = models.TextField(max_length=2000,blank=True,help_text="Explanation to be shown after the question has been answered.",verbose_name='Explanation',)
 TYPES = (
 ('radio', 'radio'),
 ('checkbox', 'checkbox'),
 ('text', 'text'),
 )
 language_code = 'en'
 translated_fields = ['content', 'feedback']
 class Meta:
 verbose_name = "Question"
 verbose_name_plural = "Questions"
 #ordering = ['category']
 def __unicode__(self):
 return self.content
class Answer(models.Model, TranslatedModelMixin):
 question = models.ForeignKey(Question)
 content = models.CharField(max_length=1000, blank=False, help_text="Enter the answer text that you want displayed",)
 es_content = models.CharField(max_length=1000, blank=False, help_text="Enter the answer text that you want displayed",)
 correct = models.BooleanField(blank=False, default=False,help_text="Is this a correct answer?")
 language_code = 'en'
 translated_fields = ['content']
 def __unicode__(self):
 return self.content
class Response(models.Model):
 user = models.ForeignKey(User)
 question = models.ForeignKey(Question)
 # Could have either an FK to an answer OR some free response text.
 answer = models.ForeignKey(Answer)
 free_response = models.TextField(max_length=2000,blank=True)
 def __unicode__(self):
 if self.answer:
 return self.answer
 else:
 return free_response

I am especially concerned with the elegance of my Response model. The idea here is a question might be multiple choice (radio group or checkbox group) OR free response (text) so a response could either be a foreign key to an answer (which may or may not be correct) OR just some plain text (probably not both). Is this a good design? What can I do to improve my models

• user49205: Thank you for using my quiz app, I hope that it is helpful. I have added few changes which you might find useful: github.com/tomwalker/django_quiz

Answer 1

You could have an abstract superclass Response which has concrete derived classes of multipleChoiceResponse and freeResponse. Then you can have a method such as checkResponse which is different for each type of respones.

EDIT:

How about this:

from django.db import models
class Response(models.Model):
 user = models.ForeignKey(User)
 question = models.ForeignKey(Question)
 class Meta:
 abstract = True
class freeResponse(Response):
 free_response = models.TextField(max_length=2000,blank=True)
class multipleChoiceResponse(Response) #does not handle multi-select (tickbox) cases
 answer = models.ForeignKey(Answer)

• broinjc: Will this work with Django models?
• M. K. Hunter: You can do inheritance with Django models. The example above does not handle the multi-select (tickbox) case, but it handles the radio-button case. You could add a method called checkResponse() which could do the checking for you. Also there might be a boolean in the superclass correct = True?