Django: Initializing a FormSet of custom forms with instances

The trick is to use a "ModelFormset" instead of just a formset since they allow initialization with a queryset. The docs are here, what you do is provide a form=* when creating the model formset and queryset=* when your instantiating the formset. The form=* arguement is not well documented (had to dig around in the code a little to make sure it is actually there).

def edit(request):    PointFormSet = modelformset_factory(Point, form = PointForm)    qset = Point.objects.all() #or however your getting your Points to modify    formset = PointFormset(queryset = qset)    if request.method == 'POST':        #deal with posting the data        formset = PointFormset(request.POST)        if formset.is_valid():            #if it is not valid then the "errors" will fall through and be returned            formset.save()        return #to your redirect    context_dict = {'formset':formset,                    #other context info                    }    return render_to_response('your_template.html', context_dict)

So the code walks through easily. If the request is a GET then the instantiated form is returned to the user. If the request is a POST and the form is not .is_valid() then the errors "fall through" and are returned in the same template. If the request is a POST and the data is valid then the formset is saved.

Hope that helps.

-Will

If you only have one possible value which you want to set, or perhaps a closed of values, it is possible to set them after the user POSTS the data to your server using commit=False

Please consider the following code:

class UserReferralView(View):    ReferralFormSet = modelformset_factory(ReferralCode,                                           form=ReferralTokenForm, extra=1)    def get(self, request):        pass    def post(self, request):        referral_formset = UserUpdateView.ReferralFormSet(request.POST)        if referral_formset.is_valid():            instances = referral_formset.save(commit=False)            for instance in instances:                instance.user = request.user                instance.save()            return redirect(reverse('referrals.success_view'))         else:            return redirect(reverse('referrals.failure_view'))