views.py

from django.shortcuts import render
from django.core.urlresolvers import reverse, reverse_lazy
from django.http import HttpResponseRedirect
from django.views.generic import View, TemplateView, FormView, UpdateView
from django.forms.formsets import formset_factory
from django.forms.models import modelformset_factory

from .models import Invitee, Extra
from .forms import RSVPForm, ExtraForm, InviteeForm

# Create your views here.
class IndexView(FormView):
    form_class = RSVPForm
    success_url = reverse_lazy('rsvp:confirm')
    template_name = 'rsvp/index.html'

    def form_valid(self, form):
        self.request.session['code'] = form.cleaned_data['code']
        return HttpResponseRedirect(self.get_success_url())

class ThanksView(TemplateView):
    template_name = 'rsvp/thanks.html'

class ConfirmView(UpdateView):
    template_name = 'rsvp/confirm.html'
    success_url = reverse_lazy('rsvp:thanks')
    form_class = InviteeForm
    model = Invitee

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        extras = self.get_object().allowed_extras
        ExtraFormSet = modelformset_factory(Extra, ExtraForm, extra=extras)
        context['extras_form'] = formset_factory(ExtraForm, extra=extras)
        return context

    def get_object(self, queryset=None):
        return Invitee.objects.get(code=self.request.session['code'])

    def post(self, request, *args, **kwargs):
        form = self.get_form()
        self.object = self.get_object()

        ExtraFormSet = modelformset_factory(Extra, ExtraForm, extra=self.object.allowed_extras)
        extra_formset = ExtraFormSet(self.request.POST)

        if form.is_valid() and extra_formset.is_valid():
            extras = extra_formset.save(commit=False)
            for extra in extras:
                extra.invitee = self.object
                extra.save()
            return HttpResponseRedirect(reverse_lazy('rsvp:thanks'))
        else:
            return self.form_invalid(form)