Django IntegrityError signup_simplesubscriber.date_created may not be NULL - django

Question

I've read every "InterityError" + "may no be NULL" post and still can't track down what's causing this error.
I've got a two-part signup form. First part is just selecting a product. That passes a product ID to the next page as part of the URL, where they input personal info. I can get the form to work fine until I start removing fields -- i'm using model forms -- because some fields don't need to be displayed.
Here's my model, and the modelForm:
class SimpleSubscriber(models.Model):
name = models.CharField(max_length=255)
address = models.CharField(max_length=200)
city = models.CharField(max_length=100)
state = models.CharField(max_length=2)
zipcode = models.CharField(max_length=9)
phone = models.CharField(max_length=10)
email = models.EmailField()
date_created = models.DateTimeField(null=True)
sub_type = models.ForeignKey(Product)
def __unicode__(self):
return self.name
class SubscriberForm(ModelForm):
class Meta:
model = SimpleSubscriber
fields = ('name', 'address', 'city', 'state', 'zipcode', 'phone', 'email', 'sub_type',)#'date_created',
And here's my views:
def select_product(request):
title = "get yourself an e-edition. wurd."
pform = Product.objects.order_by('product_active')
if request.method == 'POST': # If the form has been submitted...
pform = ProductForm(request.POST) # A form bound to the POST data
if pform.is_valid(): # All validation rules pass
# ...
return HttpResponseRedirect('signup/%i' % pform.id) # Redirect after POST
else:
form = ProductForm() # An unbound form
return render_to_response('signup/index.html', {'title': title, 'pform': pform}, context_instance=RequestContext(request))
def subscriber_signup(request, product_id):
productchoice = Product.objects.get(id=product_id)
now = datetime.datetime.now()
title = "We need some information."
if request.method == 'POST': # If the form has been submitted...
sform = SubscriberForm(request.POST) # A form bound to the POST data
if sform.is_valid(): # All validation rules pass
sform.date_created = now
sform.sub_type = productchoice
sform.save()
return HttpResponseRedirect('thankyou/') # Redirect after POST
else:
sform = SubscriberForm() # An unbound form
return render_to_response('signup/detail.html', {'title': title, 'sform': sform, 'productchoice': productchoice, 'now': now.date(),}, context_instance=RequestContext(request))
I think it has something to do with the modelForm, but I'm pretty new, so I really have no idea. If I add all the fields to SubscriberForm, then they get filled out and everything works fine. But I don't want users to have to say when they filled out the form, so i put sform.date_created = now and I want the product_id to be filled in automatically by what choice they picked on the previous page. but if I exclude these fields from the form it throws the IntegrityError, which isn't very helpful in explaining what to change.
Any hints on where I'm messing up?
Thanks,

Answer 1

Two things:
1) You may benefit from using exlude in your form definition:
class SubscriberForm(ModelForm):
class Meta:
model = SimpleSubscriber
exclude = ('date_created', )
2) To your question, heres how to fix it:
if sform.is_valid(): # All validation rules pass
suscriber = sform.save(commit=False)
suscriber.date_created = now
suscriber.sub_type = productchoice
suscriber.save()

Answer 2

Alternatively to #fceruti's suggestion, you can also add more kwarg tags null=True on the model's field where appropriate - only forcing a minimal set of fields to be completed in the form.