Django - validating and saving ModelForm with editable=false fields

I do apologise for all the questions I'm posting today, but I'm at my wits end on this one.

I'm trying to make a Q&A thing for a video site, and I'm trying to get the question to submit via AJAX.

Question model:

class Question(models.Model):
    user = models.ForeignKey(User, editable=False)
    video = models.ForeignKey(Video, editable=False)
    section = models.ForeignKey(Section, editable=False)
    title = models.CharField(max_length=255)
    description = m开发者_如何转开发odels.TextField(null=True, blank=True)

ModelForm:

class QuestionForm(ModelForm):
    def __init__(self, video, *args, **kwargs):
        super(QuestionForm, self).__init__(*args, **kwargs)
        if self.instance:
            self.fields['section'].queryset = Section.objects.filter(video=video)

    class Meta:
        model = Question

POST parameters sent by jQuery's AJAX request (the video parameter is added by the Javascript code):

section=6&title=test&description=test&video=1

And finally, here's the view I'm working on to handle the submit:

def question_submit(request):
    u = request.user
    if u.is_authenticated():
        q=QuestionForm(request.POST)

        if q.is_valid():
            logger.debug("YES!")
        else:
            logger.debug("NO!")

        f=q.save(commit=False)
        f.user=u
        f.video_id=int(request.POST['video'])

        f.save()
        return HttpResponse("OK")
    else:
        return JsonResponse({'failed': 'You are not logged in. Try logging in in a new tab, then re-submit your question.'})

As suggested by the docs, I'm saving with commit=false so that I can modify the object.

I have two problems:

1. When it reaches q.is_valid(), it throws the error "'QuestionForm' object has no attribute 'cleaned_data'".

2. If I take out the q.is_valid() bit, f.save() succeeds, but it inserts a blank row into the database.

To anyone who can help, I owe you my sanity.

You aren't passing in video in the view:

forms.py

def __init__(self, video, *args, **kwargs):

views.py

q=QuestionForm(request.POST)

as video is a positional argument, I'd imagine it is interpreting request.POST as the video?

You could change video to a keyword argument:

def __init__(self, video=None, *args, **kwargs):
    if video:
         ...

as mordi metions, you should check if a) it's a valid POST, and b) it's an ajax request

def question_submit(request):
    if request.method == "POST" and request.is_ajax():
        ... 

It's look like your request.POST is empty. Are you sure that the data is sent by POST method?, check

if request.method == 'POST:

or use

q=QuestionForm(request.REQUEST)

to get POST/GET data.