[Django]-Django: Initializing a FormSet of custom forms with instances

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29👍

✅

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

👤JudoWill

1👍

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'))
👤Oleg Belousov

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