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Django override __init__ form method using ModelForm

I have a foreign key (zone_set) as a choice field in a form. It should only display current project's zone_set . As you can see, It is not the case since it's displaying a zone_set: I belong to an other project, I should not be displayed here which does not belong to the current project.
Here is my form but it doesn't work.
class ODMatrixForm(forms.ModelForm):
class Meta:
model = ODMatrix
# fields = '__all__'
exclude = ('size', 'locked',)
def __init__(self, current_project=None, *args, **kwargs):
super().__init__(*args, **kwargs)
if current_project:
queryset = ZoneSet.objects.filter(project=current_project)
self.fields['zone_set'].queryset = queryset
The view creating the ODMatrix
def create_od_matrix(request, pk):
"""A roadnetwork depends on a project. It
must be created inside the project"""
current_project = Project.objects.get(id=pk)
form = ODMatrixForm(initial={'project': current_project})
if request.method == 'POST':
print(request)
od_matrix = ODMatrix(project=current_project)
# form = ODMatrixForm(request.POST, instance=od_marix)
form = ODMatrixForm(data=request.POST, instance=od_matrix)
if form.is_valid():
form.save()
messages.success(request, "OD matrix cessfully created")
return redirect('od_matrix_details', od_matrix.pk)
context = {
'project': current_project,
'form': form}
return render(request, 'form.html', context)

You created the __init__ as constructor of the Meta class, this should be a constructor of the ODMatrixForm, so:
class ODMatrixForm(forms.ModelForm):
# 🖟 part of ODMatrixForm, not Meta
def __init__(self, current_project=None, *args, **kwargs):
super().__init__(*args, **kwargs)
if current_project:
self.fields['zone_set'].queryset = ZoneSet.objects.filter(
project=current_project
)
class Meta:
model = ODMatrix
# fields = '__all__'
exclude = ('size', 'locked',)
In the view, you will need to pass the current_project when you construct an ODMatrixForm object:
from django.shortcuts import get_object_or_404
def create_od_matrix(request, pk):
current_project = get_object_or_404(Project, pk=pk)
if request.method == 'POST':
form = ODMatrixForm(current_project, request.POST, request.FILES)
if form.is_valid():
form.instance.project = current_project
form.save()
messages.success(request, 'OD matrix cessfully created')
return redirect('od_matrix_details', od_matrix.pk)
else:
form = ODMatrixForm(current_project=current_project)
context = {
'project': current_project,
'form': form
}
return render(request, 'form.html', context)
Note: It is often better to use get_object_or_404(…) [Django-doc],
then to use .get(…) [Django-doc] directly. In case the object does not exists,
for example because the user altered the URL themselves, the get_object_or_404(…) will result in returning a HTTP 404 Not Found response, whereas using
.get(…) will result in a HTTP 500 Server Error.

How to detailview pk in post method in DetailView? (Django)

In my detailView I have 2 methods get_context_data and post. In get_context_data I can get the detailView pk with self.object.pk but how can I get it in the post method?
[ updated ]
here is the view
class Class_detailView(LoginRequiredMixin, DetailView):
login_url = '/'
model = Class
template_name = "attendance/content/teacher/class_detail.html"
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['attendance_form'] = AttendanceForm(current_class_pk=self.object.pk) # pass data to form via kwargs
return context
def post(self, request, *args, **kwargs):
if request.method == "POST":
attendance_form = AttendanceForm(request.POST)
if attendance_form.is_valid():
attendance_form.instance.teacher = self.request.user
attendance_form.save()
return redirect('class-detail', pk=self.kwargs.get('pk'))
form
class AttendanceForm(forms.ModelForm):
class Meta:
model = Attendance
fields = ['student',]
def __init__(self, *args, **kwargs):
current_class_pk = kwargs.pop('current_class_pk')
super(AttendanceForm, self).__init__(*args, **kwargs)
current_student = Class.objects.get(id=current_class_pk)
self.fields['student'].queryset = current_student.student
I want to get the pk and pass it to the form when the post request is called.
How can I do it?

did you try this:
def post(self, request, *args, **kwargs):
if request.method == "POST":
attendance_form = AttendanceForm(request.POST, current_class_pk=self.kwargs.get('pk'))
if attendance_form.is_valid():
attendance_form.instance.teacher = self.request.user
attendance_form.save()
return redirect('class-detail', pk=self.kwargs.get('pk'))

Unable to override post method of Django UpdateView

I have a update view in django project. I need to override the post method because I am using multiple modelform.
views.py:
class EmployeeUpdateView(LoginRequiredMixin, UpdateView):
"""
Update a created a employee
"""
login_url = '/authentication/login/'
template_name = 'employee/employee_update_form.html'
form_class = EmployeeAddModelForm
work_form_class = WorkExperienceForm
education_form_class = EducationForm
queryset = Employee.objects.all()
#success_url = reverse_lazy('employee:employee-list')
def get(self, request, *args, **kwargs):
id_ = self.kwargs.get("id")
employee_id = Employee.objects.get(id=id_)
work_info = WorkExperience.objects.get(employee=employee_id)
education_info = Education.objects.get(employee=employee_id)
return render(request, self.template_name, {
'form': self.form_class(instance=employee_id),
'work_form': self.work_form_class(instance=work_info),
'education_form': self.education_form_class(instance=education_info)
}
)
def post(self, request, *args, **kwargs):
form = self.form_class(request.POST)
work_form = self.work_form_class(request.POST, prefix='work_form')
education_form = self.education_form_class(request.POST, prefix='education_form')
# Check form validation
if form.is_valid() and work_form.is_valid() and education_form.is_valid():
instance = form.save()
work = work_form.save(commit=False)
education = education_form.save(commit=False)
work.employee = instance
education.employee = instance
work.update()
education.update()
return redirect('employee:employee-list')
return render(request, self.template_name, {
'form': form,
'work_form': work_form,
'education_form': education_form
}
)
When I press update button of my form, error is giving showwing "This field already exist". It means when i update the form is post data as a new form not as a update form.
Where is error in my post method?

Django: form_valid() takes exactly 2 arguments (3 given)

I have got a CreateView for emergency lighting tests done on sites. It gets the site from the url so the user does not need to enter it into the form. The CreateView Also has a emergency lighting device formset to attach multiple devices to the main test. When I hit submit on the form i get
form_valid() takes exactly 2 arguments (3 given)
models.py
class Site(models.Model):
....
class EmergencyLighting(models.Model):
site = models.ForeignKey(Site)
class EmergencyLightingDevice(models.Model):
emergency_lighting = models.ForeignKey(EmergencyLighting)
views.py
class FormsetMixin(object):
object = None
def get(self, request, *args, **kwargs):
if getattr(self, 'is_update_view', False):
self.object = self.get_object()
form_class = self.get_form_class()
form = self.get_form(form_class)
formset_class = self.get_formset_class()
formset = self.get_formset(formset_class)
return self.render_to_response(self.get_context_data(form=form, formset=formset))
def post(self, request, *args, **kwargs):
if getattr(self, 'is_update_view', False):
self.object = self.get_object()
form_class = self.get_form_class()
form = self.get_form(form_class)
formset_class = self.get_formset_class()
formset = self.get_formset(formset_class)
if form.is_valid() and formset.is_valid():
return self.form_valid(form, formset)
else:
return self.form_invalid(form, formset)
def get_formset_class(self):
return self.formset_class
def get_formset(self, formset_class):
return formset_class(**self.get_formset_kwargs())
def get_formset_kwargs(self):
kwargs = {
'instance': self.object
}
if self.request.method in ('POST', 'PUT'):
kwargs.update({
'data': self.request.POST,
'files': self.request.FILES,
})
return kwargs
def form_valid(self, form, formset):
self.object = form.save()
formset.instance = self.object
formset.save()
return redirect('/sites/list')
def form_invalid(self, form, formset):
return self.render_to_response(self.get_context_data(form=form, formset=formset))
class EmergencyLightingCreate(FormsetMixin, CreateView):
template_name = 'emergency_lighting/emergencylighting_form.html'
model = EmergencyLighting
form_class = EmergencyLightingForm
formset_class = EmergencyLightingFormSet
def form_valid(self, form):
emergency_lighting = form.save(commit=False)
emergency_lighting.site_id = self.kwargs['site']
return super(EmergencyLightingCreate, self).form_valid(form)
forms.py
class EmergencyLightingForm(forms.ModelForm):
class Meta:
model = EmergencyLighting
exclude = ('creation', 'last_modified')
class EmergencyLightingDeviceForm(forms.ModelForm):
class Meta:
model = EmergencyLightingDevice
exclude = ('creation', 'last_modified')
EmergencyLightingFormSet = inlineformset_factory(EmergencyLighting, EmergencyLightingDevice,
extra=0, min_num=1, exclude=('creation', 'last_modified'))
urls.py
url(r'^(?P<site>[0-9]+)/create/$', EmergencyLightingCreate.as_view(), name='emergency-lighting-create'),

Like the error says, you're passing three arguments to form_valid; that's because you explicitly overrode post to send those three, and modified the signature of form_valid in FormsetMixin to accept them. However in EmergencyLightingCreate you've reverted to only accepting two arguments. You need to be consistent about how many arguments your methods accept when you're subclassing.

Django ModelForm within DetailView

I have a DetailView which displays a Post. I now want to add the ability to create a Comment for a Post. For that I need a CommentForm, within the DetailView, so that I can create comments while being on the same page with a Post.
Is this possible, or should I be looking for another approach, like doing the form handling 'manually'?
class Comment(models.Model):
body = models.TextField()
created_at = models.DateTimeField(auto_now_add=True)
author_name = models.CharField(max_length=255)
parent_post = models.ForeignKey('Post',related_name='comments')
class PostDetailView(BlogMixin,DetailView):
""" A view for displaying a single post """
template_name = 'post.html'
model = Post
#Add some code for the CommentForm here?
class CommentForm(forms.ModelForm):
class Meta:
model = Comment
exclude = ("parent_post","created_at")
def create_view(request, **kwargs):
if request.method == "POST":
parent_fk = request.args['parent_fk'] #Im hoping to find how this will work soon
form = CommentForm(request.POST)
if form.is_valid():
new_comment = form.save(commit=False)
new_comment.parent_post = parent_fk
new_comment.save()
return HttpResponseRedirect(request.META.get('HTTP_REFERER'))
** Alternative **
I have been trying to apply the solution - A better alternative - but I get
Exception Value: __init__() takes exactly 1 argument (3 given)
Exception Location: .../sitepackages/django/core/handlers/base.py in get_response, line 112
and have not been able to trace it yet.
class PostView(BlogMixin,DetailView):
""" A view for displaying a single post """
template_name = 'post.html'
model = Post
def get_context_data(self, **kwargs):
context = super(PostView, self).get_context_data(**kwargs)
context['form'] = CommentForm()
return context
class PostDetailView(View):
def get(self, request, *args, **kwargs):
view = PostView.as_view()
return view(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
view = PostComment.as_view()
return view(request, *args, **kwargs)
class PostComment( SingleObjectMixin , FormView):
template_name = 'post.html'
form_class = CommentForm
model = Post
def post(self, request, *args, **kwargs):
self.object = self.get_object()
return super(PostComment, self).post(request, *args, **kwargs)
def get_success_url(self):
return reverse('post-detail', kwargs={'pk': self.object.pk})
class BlogMixin(object):
"""
Basic mixin for all the views. Update the context with additional
information that is required across the whole site, typically
to render base.html properly
"""
def get_context_data(self, *args, **kwargs):
context = super(BlogMixin, self).get_context_data(*args, **kwargs)
blog = Blog.get_unique()
context.update({
'blog': blog,
'active_user': users.get_current_user(),
'is_admin': users.is_current_user_admin()
})
return context
urls.py:
url(r'^post/(?P[\d]+)/$', views.PostDetailView., name="post-detail"),

If you want to use your first method, you can make the FK a hidden field. In your view, you can save the FK before committing the comment to the database. Like this:
if form.is_valid():
comment = form.save(commit=False)
comment.parent_post = parent_post
comment.save()
Edit: If you want to fetch the comments, then you can use filter by post to get a QuerySet of the comments.

Why dont you send your form in the context in detail view:
class YourDetailView(DetailView):
#Your stuff here
def get_context_date(self, **kwargs):
context = super(YOurDetailView, self).get_context_data(**kwargs)
context['form'] = YourForm
return context
PS. Look for the parameters in get_context_date..

In the end I could not make it work with the redirect, but the following is working:
class PostDetailView(BlogMixin,CreateView):
""" A view for displaying a single post """
template_name = 'post.html'
model = Comment
fields = ['body','author_name']
def get_context_data(self, **kwargs):
context = super(PostDetailView, self).get_context_data(**kwargs)
context['post'] = Post.objects.get(pk=self.kwargs['pk'])
return context
def form_valid(self, form):
# self.object = form.save()
obj = form.save(commit=False)
obj.parent_post = Post.objects.get(pk=self.kwargs['pk'])
obj.save()
return redirect('post-detail', self.kwargs['pk'])