问题
I am having 2 issues, one if you submit and click back and then submit again it duplicates the instance in the database - in this case Household. In addition it is saving the parent 'Household' without the child 'Applicants' despite me setting min_num=1
can someone point me in the right direction to resolve this issue.
Many thanks in advance
class Application(models.Model):
name = models.CharField(max_length=100, blank=True, null=True)
application_no = models.CharField(max_length=100, unique=True, default=create_application_no)
created_date = models.DateTimeField(auto_now_add=True)
user = models.ForeignKey(
settings.AUTH_USER_MODEL,
on_delete=models.CASCADE
)
class HouseHold(models.Model):
name = models.CharField(max_length=100)
application = models.ForeignKey(Application, on_delete=models.CASCADE)
no_of_dependents = models.PositiveIntegerField(default=0)
class Applicant(models.Model):
first_name = models.CharField(max_length=100)
last_name = models.CharField(max_length=100)
household = models.ForeignKey("HouseHold", on_delete=models.CASCADE)
forms.py
class ApplicationForm(ModelForm):
class Meta:
model = Application
fields = (
"name",
)
class ApplicantForm(ModelForm):
class Meta:
model = Applicant
fields = [
"household",
"first_name",
"last_name"
]
class HouseHoldForm(ModelForm):
class Meta:
model = HouseHold
fields = [
'name',
'application',
'no_of_dependents'
]
def __init__(self, application_id=None, *args, **kwargs):
super(HouseHoldForm, self).__init__(*args, **kwargs)
self.fields['name'].label = 'House Hold Name'
if application_id:
self.fields['application'].initial = application_id
self.fields['application'].widget = HiddenInput()
ApplicantFormset = inlineformset_factory(
HouseHold, Applicant, fields=('household', 'first_name', 'last_name'), can_delete=False, extra=1, validate_min=True, min_num=1)
views.py
class HouseHoldCreateView(LoginRequiredMixin, generic.CreateView):
model = models.HouseHold
template_name = "households/household_create.html"
form_class = HouseHoldForm
def get_parent_model(self):
application = self.kwargs.get('application_pk')
return application
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
if self.request.POST:
context['application'] = models.HouseHold.objects.filter(application_id=self.kwargs['application_pk']).last()
context['house_hold_formset'] = ApplicantFormset(self.request.POST, instance=self.object)
else:
context['application'] = models.Application.objects.get(id=self.kwargs['application_pk'])
context['house_hold_formset'] = ApplicantFormset()
return context
def get_form_kwargs(self):
kwargs = super(HouseHoldCreateView, self).get_form_kwargs()
print(kwargs)
kwargs['application_id'] = self.kwargs.get('application_pk')
return kwargs
def form_valid(self, form):
context = self.get_context_data()
applicants = context['house_hold_formset']
with transaction.atomic():
self.object = form.save()
if applicants.is_valid():
applicants.instance = self.object
applicants.save()
return super(HouseHoldCreateView, self).form_valid(form)
def get_success_url(self):
if 'addMoreApplicants' in self.request.POST:
return reverse('service:household-create', kwargs={'application_pk': self.object.application.id})
return reverse('service:household-list', kwargs={'application_pk': self.object.application.id})
回答1:
I had a similar problem, I solved it by adding the post() method to the view. The example is an UpdateView but the usage is the same. (the indentation is not correct but that's what stackoverflow's editor let me do, imagine all methods are 4 spaces to the right)
class LearnerUpdateView(LearnerProfileMixin, UpdateView):
model = User
form_class = UserForm
formset_class = LearnerFormSet
template_name = "formset_edit_learner.html"
success_url = reverse_lazy('home')
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
learner = User.objects.get(learner=self.request.user.learner)
formset = LearnerFormSet(instance=learner)
context["learner_formset"] = formset
return context
def get_object(self, queryset=None):
user = self.request.user
return user
def post(self, request, *args, **kwargs):
self.object = self.get_object()
form_class = self.get_form_class()
form = self.get_form(form_class)
user = User.objects.get(learner=self.get_object().learner)
formsets = LearnerFormSet(self.request.POST, request.FILES, instance=user)
if form.is_valid():
for fs in formsets:
if fs.is_valid():
# Messages test start
messages.success(request, "Profile updated successfully!")
# Messages test end
fs.save()
else:
messages.error(request, "It didn't save!")
return self.form_valid(form)
return self.form_invalid(form)
Keep in mind that to save the formset correctly you have to do some heavy lifting in the template as well. I'm referring to the hidden fields which can mess up the validation process. Here's the template corresponding to the view posted above:
<form action="" method="POST" enctype="multipart/form-data">
{% csrf_token %}
{{ form|crispy }}
{{ learner_formset.management_form}}
{% for form in learner_formset %}
{% if forloop.first %}
{% comment %} This makes it so that it doesnt show the annoying DELETE checkbox {% endcomment %}
{% for field in form.visible_fields %}
{% if field.name != 'DELETE' %}
<label for="{{ field.name }}">{{ field.label|capfirst }}</label>
<div id="{{ field.name }}" class="form-group">
{{ field }}
{{ field.errors.as_ul }}
</div>
{% endif %}
{% endfor %}
{% endif %}
{% for field in form.visible_fields %}
{% if field.name == 'DELETE' %}
{{ field.as_hidden }}
{% else %}
{# Include the hidden fields in the form #}
{% if forloop.first %}
{% for hidden in form.hidden_fields %}
{{ hidden }}
{% endfor %}
{% endif %}
{% endif %}
{% endfor %}
{% endfor %}
<input class="btn btn-success" type="submit" value="Update"/>
Additional reading :
- https://medium.com/@adandan01/django-inline-formsets-example-mybook-420cc4b6225d
- Save formset in an UpdateView
回答2:
Inspired by Beikini I have solved it using the create View
class HouseHoldCreateView(LoginRequiredMixin, generic.CreateView):
model = HouseHold
template_name = "households/household_create3.html"
form_class = HouseHoldForm
def get_parent_model(self):
application = self.kwargs.get('application_pk')
return application
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
if self.request.POST:
context['application'] = HouseHold.objects.filter(
application_id=self.kwargs['application_pk']).last()
context['house_hold_formset'] = ApplicantFormset(self.request.POST)
else:
context['application'] = Application.objects.get(id=self.kwargs['application_pk'])
context['house_hold_formset'] = ApplicantFormset()
return context
def get_form_kwargs(self):
kwargs = super(HouseHoldCreateView, self).get_form_kwargs()
kwargs['application_id'] = self.kwargs.get('application_pk')
return kwargs
def form_valid(self, form):
context = self.get_context_data()
applicants = context['house_hold_formset']
application_id = self.kwargs['application_pk']
household_form = self.get_form()
if form.is_valid() and applicants.is_valid():
with transaction.atomic():
self.object = form.save()
applicants.instance = self.object
applicants.save()
messages.success(self.request, 'Applicant saved successfully')
return super(HouseHoldCreateView, self).form_valid(form)
else:
messages.error(self.request, 'please add an applicant to the household')
return self.form_invalid(form)
def get_success_url(self):
return reverse('service:household-list', kwargs={'application_pk': self.object.application.id})
来源：https://stackoverflow.com/questions/64998608/inlineformset-factory-saving-parent-without-child-and-not-displaying-validation