Question

Let’s consider this model

class Session(models.Model):
  tutor = models.ForeignKey(User)
  start_time = models.DateTimeField()
  end_time = models.DateTimeField()

I’m trying to post values for start_time and end_time and automatically give tutor the current logged in user.

My form is actually managing only start_time and end_time

class SessionForm(forms.ModelForm):
  class Meta:
    model = Session
    exclude = ['tutor']

And my view adds the tutor:

def post(request):
  """Session post"""
  if request.method == 'POST':
    form = SessionForm(request.POST)
    form.tutor = request.user
    if form.is_valid():
      form.save()
      obj = {'posted': True}
      return HttpResponse(json.dumps(obj), mimetype='application/json')
    else:
      return render_to_response('planner/editor.html',
          form, context_instance=RequestContext(request),)

I’m getting a

Column ‘tutor_id’ cannot be null

What am I doing wrong ?

Answer 1

.Set tutor to form.instance

Instead of:

form.tutor = request.user
if form.is_valid():
  form.save()

You should have:

form.instance.tutor = request.user
if form.is_valid():
  form.save()

But personnaly I’d rather tweak form.instance after form.is_valid(), just before form.save().