Question

So I’m building a basic Q&A site– Each topic has a series of questions associated with it, and each question has multiple answers associated with it.

I’m creating the user input for questions and they have to associated with a topic. This is the questions model

#models.py
class Question(models.Model):
    movie           = models.ForeignKey(Movie, blank=True, null=True)
    question_text   = models.CharField(max_length = 1000)
    question_detail = models.CharField(max_length = 5000, blank = True, null = True)
    q_pub_date      = models.DateTimeField(auto_now_add = True)
    q_author        = models.ForeignKey(User)
class QuestionForm(ModelForm):
    def save(self, user = None, force_insert = False, force_update = False, commit = True):
        q = super(QuestionForm, self).save(commit = False)
        q.q_author = user
        if commit:
            q.save()
        return q

    class Meta:
        model = Question
        exclude = ('movie', 'q_author', 'q_pub_date')

This is the URL conf

#urls.py
url(r'^(?P<movie_id>\d+)/add_question/$', 'add_question'),

Now here is the view

#views.py
def add_question(request, movie_id):
    if request.method == "POST":
        form = QuestionForm(request.POST, request.FILES)
        #QuestionForm.movie = Movie.objects.get(pk = movie_id)
        if form.is_valid():
            form.save(user = request.user)
            return HttpResponseRedirect("/home/")
    else:
        form = QuestionForm()
    return render_to_response("qanda/add_question.html", {'form': form}, context_instance = RequestContext(request))

This is the HTML code

#add_question.html
<h1> Add Question: {{ user.username }}</h1>
    <form action = "" method = "post">{% csrf_token %}
        {{ form.as_p }}
        <input type = "submit" value = "Ask" />
        <input type = "hidden" name = "next" value = "{{ next|escape }}" />
    </form>

In the view, the commented out line is what I added to the view to try and auto save the model. When adding a question, the URL has the ID of the movie it is associated with, and my thought is to take that ID and then plug it into the ForeignKey to identify which movie is associated with the question. However, when I use my code, it changes all of the Questions’ movie associations to the current movie instead of just changing that specific question’s movie association. Without the code, it doesn’t associate a Movie with the Question at all. How do I fix this?

Answer 1

Use this:

#views.py
def add_question(request, movie_id):
    if request.method == "POST":
        form = QuestionForm(request.POST, request.FILES)
        if form.is_valid():
            question = form.save(user = request.user)
            question.movie = Movie.objects.get(pk = movie_id)
            question.save()
            return HttpResponseRedirect("/home/")
    else:
        form = QuestionForm()
    return render_to_response("qanda/add_question.html", {'form': form}, context_instance = RequestContext(request)

For question asked in comment

You should avoid using absolute URLs in views or templates. Consider a scenario, where you decide to change home URL from /home/ to /myhome/. You will have to edit it where ever you have used them. It is always better to name the urls (docs):

# URL Conf
url(r'^home/$', 'home_view', name="home_url"),
url(r'^(?P<movie_id>\d+)/add_question/$', 'add_question', name="add_question_url"),
url(r'^home/(?P<movie_id>\d+)/$', 'movie_view', name="movie_url"),

The name argument act as an unique identifier to your actual URLs

Now in you views:

from django.core.urlresolvers import reverse

def some_view(request):
    ...
    return HttpResponseRedirect(reverse('home_url'))

Now what ever change you make to the URL (say /home/ to /myhome/ makes no effect to the view as long as the name argument has the same value in the URL conf.

If you wish to pass parameters (like movie_id in your case)

def some_view(request, movie_id):
    ...
    return HttpResponseRedirect(reverse('movie_url', kwargs={'movie_id':movie_id}))

The same concept should be used in templates to avoid hard-coding URLS in templates. Please read this for more details