Django class-based CreateView and UpdateView with multiple inline formsets

Question

I have been trying to do Django class-based CreateView and UpdateView with multiple inline formsets

CreateView works fine but UpdateView is not working properly, If anyone tried UpdateView with multiple inline formsets, anyone tried pls share updateview code snippet.

# models.py
from django.db import models

class Recipe(models.Model):
    title = models.CharField(max_length=255)
    description = models.TextField()

class Ingredient(models.Model):
    recipe = models.ForeignKey(Recipe)
    description = models.CharField(max_length=255)

class Instruction(models.Model):
    recipe = models.ForeignKey(Recipe)
    number = models.PositiveSmallIntegerField()
    description = models.TextField()


# forms.py
from django.forms import ModelForm
from django.forms.models import inlineformset_factory
from .models import Recipe, Ingredient, Instruction

class RecipeForm(ModelForm):
    class Meta:
        model = Recipe

IngredientFormSet = inlineformset_factory(Recipe, Ingredient, extra=0)
InstructionFormSet = inlineformset_factory(Recipe, Instruction, extra=0)


# views.py
from django.http import HttpResponseRedirect
from django.views.generic.edit import CreateView, UpdateView
from django.shortcuts import get_object_or_404

from .forms import IngredientFormSet, InstructionFormSet, RecipeForm
from .models import Recipe

class RecipeCreateView(CreateView):
    template_name = 'recipe_add.html'
    model = Recipe
    form_class = RecipeForm
    success_url = '/account/dashboard/'

    def get(self, request, *args, **kwargs):
        self.object = None
        form_class = self.get_form_class()
        form = self.get_form(form_class)
        ingredient_form = IngredientFormSet()
        instruction_form = InstructionFormSet()
        return self.render_to_response(
            self.get_context_data(form=form,
                                  ingredient_form=ingredient_form,
                                  instruction_form=instruction_form))

    def post(self, request, *args, **kwargs):
        self.object = None
        form_class = self.get_form_class()
        form = self.get_form(form_class)
        ingredient_form = IngredientFormSet(self.request.POST)
        instruction_form = InstructionFormSet(self.request.POST)
        if (form.is_valid() and ingredient_form.is_valid() and
            instruction_form.is_valid()):
            return self.form_valid(form, ingredient_form, instruction_form)
        else:
            return self.form_invalid(form, ingredient_form, instruction_form)

    def form_valid(self, form, ingredient_form, instruction_form):
        self.object = form.save()
        ingredient_form.instance = self.object
        ingredient_form.save()
        instruction_form.instance = self.object
        instruction_form.save()
        return HttpResponseRedirect(self.get_success_url())

    def form_invalid(self, form, ingredient_form, instruction_form):
        return self.render_to_response(
            self.get_context_data(form=form,
                                  ingredient_form=ingredient_form,
                                  instruction_form=instruction_form))

class RecipeUpdateView(UpdateView):
    template_name = 'recipe_add.html'
    model = Recipe
    form_class = RecipeForm

    def get_success_url(self):
        self.success_url = '/account/dashboard/'
        return self.success_url

    def get_context_data(self, **kwargs):
        context = super(RecipeUpdateView, self).get_context_data(**kwargs)
        if self.request.POST:
            context['form'] = RecipeForm(self.request.POST, instance=self.object)
            context['ingredient_form'] = IngredientFormSet(self.request.POST, instance=self.object)
            context['instruction_form'] = InstructionFormSet(self.request.POST, instance=self.object)
        else:
            context['form'] = RecipeForm(instance=self.object)
            context['ingredient_form'] = IngredientFormSet(instance=self.object)
            context['instruction_form'] = InstructionFormSet(instance=self.object)
        return context

    def post(self, request, *args, **kwargs):
        self.object = None
        form_class = self.get_form_class()
        form = self.get_form(form_class)
        ingredient_form = IngredientFormSet(self.request.POST)
        instruction_form = InstructionFormSet(self.request.POST)
        if (form.is_valid() and ingredient_form.is_valid() and
            instruction_form.is_valid()):
            return self.form_valid(form, ingredient_form, instruction_form)
        else:
            return self.form_invalid(form, ingredient_form, instruction_form)

    def form_valid(self, form, ingredient_form, instruction_form):
        self.object = form.save()
        ingredient_form.instance = self.object
        ingredient_form.save()
        instruction_form.instance = self.object
        instruction_form.save()
        return HttpResponseRedirect(self.get_success_url())

    def form_invalid(self, form, ingredient_form, instruction_form):
        return self.render_to_response(
            self.get_context_data(form=form,
                                  ingredient_form=ingredient_form,
                                  instruction_form=instruction_form))

Thanks in advance.

Answer 1

My guess is that you can't do

self.object = None

on overwritten post method in a UpdateView. So, try

self.object = self.get_object()

instead, once you already have an object instance in this case.