Django inlineformset_factory - django

Question

I'm stuck on a problem with Django framework. In detail, user can create a Group and associate Member (>=1 && <=3) to the group. Each member is identified by email address (unique). However, the same member can partecipate with different name and surname in different groups. So I have a many to many relationship (using through) between Group and Member.
In my view I've an inlineformset. However when I submit the form I always get:
archi_groupmember.group_id may not be NULL
I've changed the widget for the MemberGroup form, because the user don't have to select a member from a select but he has to type the member's mail.
So I think I should persist the member just before to save the MemberGroup, but I don't know how to do it!
I'm totally new to Django, I'm following the docs.
Thank you all for any help!!
Here a page screenshot just to clarify: http://postimg.org/image/bndh5ug29/
Following my code.
Models.py:
class Group(models.Model):
user = models.ForeignKey(User)
limit = Q(active = True)
project = models.ForeignKey(Project, limit_choices_to = limit)
name = models.CharField(max_length=100)
code = models.CharField(max_length=100, unique=True)
def __unicode__(self):
return self.name
class Member(models.Model):
groups = models.ManyToManyField(Group, through='GroupMember')
email = models.EmailField(max_length=254, unique=True)
def __unicode__(self):
return self.email
class GroupMember(models.Model):
group = models.ForeignKey(Group)
member = models.ForeignKey(Member)
name = models.CharField(max_length=100)
surname = models.CharField(max_length=100)
views.py:
#login_required
#user_passes_test(first_login_check, login_url='/detail')
def partecipate(request):
from django.forms import TextInput
MemberFormSet = inlineformset_factory(Group, Member.groups.through, form=GroupMemberForm, can_delete=False, extra=3, widgets={'member': TextInput() } )
if request.method == 'POST':
form = GroupForm(request.POST)
member_set = MemberFormSet(request.POST)
if form.is_valid():
for form in member_set:
print vars( form['member'] )
group = form.save(commit=False)
group.user = request.user
group.code = ''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(10))
group.save()
member_set = MemberFormSet(request.POST, instance=group)
member_set = member_set.save(commit=False)
payment = Payment()
payment.group = group
payment.invoice = _createInvoice(group.project.id, group.id)
payment.save()
return HttpResponseRedirect("/")
else:
return render(request, "partecipate.html", { 'form': form, 'member_set' : member_set })
else:
form = GroupForm()
form.Meta.model.project.queryset = Project.objects.filter(active=True)
member_set = MemberFormSet(initial=[ {'name': request.user.first_name,'surname': request.user.last_name,'member':request.user.email} ])
return render(request, "partecipate.html", { 'form': form, 'member_set' : member_set })

Answer 1

What version of Django are you using?
Since 1.3 the help docs has an example of using inlineformset_factory. And the example (link below) clearly shows passing in an instance of the parent record. Without that, your formsets will not be linked to real data.
https://docs.djangoproject.com/en/1.7/topics/forms/modelforms/#using-an-inline-formset-in-a-view
I'm also suspicious of specifying the Member.groups.through table class as the child. I would think you should leave it as Member, because the through table is part of the internal machinery.