I can't seem to find a good way to solve this situation.
I have two models Office and People with a many to many relationship through a Contact model with additional fields.
Now in my views (CreateView and UpdateView), I am using inline formset to manage the relationship.
My problem here is with UpdateView, how do I update the many to many relationship? I can add new items. But how to delete existing ones? The formset generates a checkbox DELETE but I get lost in the code. How to use it?
One way could be to delete all the corresponding rows in the through model and recreates new ones with data submitted from the form but I believe there should be a more efficient way to do it.
Can someone help?
Here's my current code:
def post(self, request, *args, **kwargs):
self.object = self.get_object()
form_class = self.get_form_class()
form = self.get_form(form_class)
formset = OfficeContactInline(request.POST, instance=self.object)
if form.is_valid() and formset.is_valid():
self.object = form.save()
contacts = formset.save(commit=False)
for contact in contacts:
contact.office = self.object
contact.save()
formset.save_m2m()
return HttpResponseRedirect(self.get_success_url())
else:
return render(request, self.template_name, self.get_context_data(form=form, formset=formset))
I finally found a solution to my problem. There actually is a change in behavior with Django 1.7: formset.save(commit=False) no longer deletes deleted items (checkbox checked).
You therefore have to use formset.deleted_objects to do it: working code below
def post(self, request, *args, **kwargs):
self.object = self.get_object()
form_class = self.get_form_class()
form = self.get_form(form_class)
formset = OfficeContactInline(request.POST, instance=self.object)
if form.is_valid() and formset.is_valid():
self.object = form.save()
contacts = formset.save(commit=False)
# New with Django 1.7
for del_contact in formset.deleted_objects:
del_contact.delete()
for contact in contacts:
contact.office = self.object
contact.save()
formset.save_m2m()
return HttpResponseRedirect(self.get_success_url())
else:
return render(request, self.template_name, self.get_context_data(form=form, formset=formset))
This is documented here: https://docs.djangoproject.com/en/1.7/topics/forms/formsets/#django.forms.formsets.BaseFormSet.can_delete
Related
i am practicing CBV , so i thought to check if i can override methodes, well one of biggest problems is that idk how to use data(like data just submitted ), i wrote this code for a DetailView so i could see post and comments under it:
class ArtDetailView(FormView, DetailView):
model = Art
form_class = CommentForm
def get_context_data(self, **kwargs):
context = super(ArtDetailView, self).get_context_data(**kwargs)
context['time'] = timezone.now()
context['form'] = self.get_form()
return context
def form_valid(self, form):
form.instance.writer = self.request.user
form.instance.text = self.post
#form.instance.art = Art.objects.get(id=self.pk)
form.save()
return super().form_valid(form)
def get_success_url(self) -> str:
return reverse('pages:art_detail', args=(self.kwargs['pk'],))
forms.py:
from django import forms
from .models import Art, Comment
class CommentForm(forms.ModelForm):
class Meta():
model = Comment
fields = ['text','art']
but when i post something it is in this shape:screen_shot(2nd comment)
,i think problem is withform.instance.text = self.post but i don't know how to fix it
can you please also explain a little because all i want is to learn.
and i tried to also add art as autofill(i added as comment) but wasn't successful, can you pls check it it too.
You can overide post method to save form as well. Since you only adding form which is always a text and no possible errors in forms unless blank. You code snippet will look like this
# In forms.py
def CommentForm(forms.ModelForm):
class Meta:
model = Comment
fields = ('text', )
# In views.py
class ArtDetailView(FormView, DetailView):
# same as previous but remove form_valid method
def post(self, request, *args, **kwargs):
form = CommentForm(request.POST)
if form.is_valid():
form_instance = form.save(commit=False)
# this will give form instance and then add related field and save again (commit=True by default)
form_instance.writer = request.user
# since it is art detail view, self.get_object() will give art object
form_instance.art = self.get_object()
form_instance.save()
return HttpResponseRedirect(self.get_success_url())
else:
return super().form_invalid(from)
If you go to FormView declaration you will find like this
I am writing a django ListView with FormMixin, but it can't handle form errors. The model limits input to 140 characters, when I inspect and change limit to 200 and submit I get
'PostListView' object has no attribute 'object_list'"
Here's the code
class PostListView(FormMixin, generic.ListView):
model = Post
form_class = PostForm
paginate_by = 10
template_name = 'index.html'
def get_success_url(self):
return reverse('index')
def post(self, request, *args, **kwargs):
form = PostForm(request.POST)
if form.is_valid():
form.save()
return super().form_valid(form)
else:
return self.form_invalid(form)
With everything working normally, it saves the data and displays the list. On error, no error, it fails.
EDIT
As #crimsonpython24 has said, ListView is for displaying data. I opted to use a basic view
def index(request):
'''deal with post method first'''
if request.method == 'POST':
form = PostForm(request.POST)
if form.is_valid():
form.save()
return redirect(reverse('index'))
else:
form = PostForm
posts = Post.objects.all()
return render(request, 'index.html', {'form':form, 'posts':posts})
This allows for invalid form data to be returned for correction, and also allows viewing of posts
The point is that ListView is only supposed to view objects. If you have a form in your view, try to go for one of the edit views, which lets you create, update, and delete (now I'm assuming that you also handle a form in this view).
I can't exactly describe how ListView causes your problem other than it does not fit your purpose and there are better alternatives.
EDIT
Now you're concatenating a FormView and ListView. However, I will still recommend going for a FormView as a ListView doesn't have a form_class attribute. It's easy, though. Let's say you have this FormView class:
class ContactView(FormView):
template_name = 'contact.html'
form_class = ContactForm # Now you can simply do this to your form
success_url = '/thanks/'
def form_valid(self, form):
form.send_email()
return super().form_valid(form)
and then simply pass in context data to make it behave partially like a ListView:
class ContactView(FormView):
# whatever you have here already
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['now'] = timezone.now()
return context
So now your new view will render both your form and context data. Seeing as both these views don't require a primary key to operate, I don't see any problem implmenting this.
I would like to be able to check if the user accessing a page is a specific user.
For instance, when a user accesses the "Edit Post" page on my blog app, I want to ensure that the user is the author of the post.
Currently, I check that the user accessing '/Blog/Edit//' has the blog.change_post permission.
However, if a second user (who also has that permission) were to enter the URL to change someone else's post, they would pass that permission check and be able to edit someone else's post.
What I want is a #user_passes_test function that check's the user object accessing the view against the author attribute of the post.
#/Blog/urls.py
urlpatterns = [
...
path('Edit/<int:pk>', views.BlogEdit, name='BlogEdit'),
...
]
#/Blog/views.py
#permission_required('blog.change_post', login_url='/Portal/login')
def BlogEdit(request, pk):
post = get_object_or_404(Post, pk=pk)
if request.method == "POST":
form = PostForm(request.POST, instance=post)
if form.is_valid():
post = form.save(commit=False)
post.save()
return redirect('/Blog', pk=post.pk)
else:
form = PostForm(instance=post)
return render(request, 'Blog/Edit.html', {'form': form})
You can add an extra filter to your get_object_or_404:
#permission_required('blog.change_post', login_url='/Portal/login')
def BlogEdit(request, pk):
post = get_object_or_404(Post, pk=pk, author=request.user)
if request.method == "POST":
form = PostForm(request.POST, instance=post)
if form.is_valid():
form.save()
return redirect('/Blog', pk=post.pk)
else:
form = PostForm(instance=post)
return render(request, 'Blog/Edit.html', {'form': form})
Here author is the hypothetical ForeignKey from Post to the user model. It is possible that the name is different, but the idea is still the same.
This thus means that in case the pk is the pk of a Blog for which request.user is not the author, then we will have a 404 response.
The advantage of filtering here, is that we use a single query for the filtering. We will not (lazily) load the author to check if it is the same as the logged in user.
Note: post = form.save(commit=False) and post.save() are equivalent to post = form.save() (so with commit=True).
In a class based view change the get_queryset method to filter by current user.
class MyView(LoginRequiredMixin, UpdateView):
...
def get_queryset(self):
"""
Only the current logged in user can edit ...
"""
return super().get_queryset().filter(created_by=self.request.user)
I figured it out from This Post in the end. What urbanspaceman suggests works for class based views, but for function based views you can do:
#permission_required('blog.change_post', login_url='/Portal/login')
def BlogEdit(request, pk):
post = get_object_or_404(Post, pk=pk)
if post.author != request.user:
raise Http404("You are not allowed to edit this Post")
# ... Rest of view here ... #
I'm trying to set my form validation in my view and I would like to get you help because I have a little issue.
This is my formset :
DocumentFormSet = inlineformset_factory(Publication, Document, form=DocumentForm, extra=1, max_num=4, can_delete=True)
This is my code :
def get_context_data(self, **kwargs):
context = super(PublicationCreateView, self).get_context_data(**kwargs)
document_queryset = Document.objects.all()
context['FormSets'] = DocumentFormSet(self.request.POST or None, self.request.FILES or None,
prefix='doc', queryset=document_queryset)
return context
def form_valid(self, form):
try:
context = self.get_context_data()
formsets = context['FormSets']
if form.is_valid():
self.object = form.save(commit=False)
if formsets.is_valid():
formsets.instance = self.object
formsets.save(commit=False)
for element in formsets:
element.save(commit=False)
self.object = form.save()
formsets.save()
return super(PublicationCreateView, self).form_valid(form)
except IntegrityError:
...
I read some things, especially form has to be save before forms in formset if there is ForeignKey between form and forms in my formset.
The issue comes if I have wrong field in my formset. As the first form is saved, it creates an object with only the first form and not with the associated form in my formset.
This is an example :
As you can see, it saves my first form, but I don't want until all the formset is valid.
I have to switch between .save(commit=False) and .save() methods.
Thank you
So, don't save the main form first.
if form.is_valid() and formsets.is_valid():
self.object = form.save()
formsets.instance = self.object
formsets.save()
(Note, you don't need to save the formset forms individually; just remove the commit=False both times.)
Im trying to save a form using UpdateView in Django 1.3 and seemed to have run into a problem. When I am saving the form, it POST's to the current URL and the success url is the same url.
When saving the form, the data seems to be changed because all the fields on the page are updated, but when I refresh, everything seems to revert.
The form is a Model Form and here is my view:
class UserProfileView(UpdateView):
context_object_name = 'profile'
def get_template_names(self):
return ['webapp/user_profile.html']
def get_queryset(self):
pk = self.kwargs.get('pk', None)
if pk is not None:
user = User.objects.get(pk=pk)
else:
raise AttributeError(u"Could not locate user with pk %s"
% pk)
if user.contributor_profile.all():
queryset = Contributor.objects.filter(user__pk=pk)
else:
queryset = Member.objects.filter(user__pk=pk)
return queryset
def get_object(self, queryset=None):
if queryset is None:
queryset = self.get_queryset()
return queryset.get()
I dont see what could be going wrong, seeing as Django saves the form through the UpdateView class and the Mixin's it extends. Has anyone run into this problem before?
Figured out the solution. The problem was happening because there was an error in the form that wasnt being reported. This seems to occur with hidden fields that need to be set in some way in order for the form to be valid.
The solution is pretty simple. You just need to override the post function and account for any hidden fields:
def post(self, request, *args, **kwargs):
pk = self.kwargs.get('pk', None)
if pk is not None:
user = User.objects.get(pk=pk)
else:
raise AttributeError(u"Could not locate user with pk %s"
% pk)
if user.contributor_profile.all():
contributor = Contributor.objects.get(user=user)
form = ContributorForm(request.POST, instance=contributor)
else:
member = Member.objects.get(user=user)
form = MemberForm(request.POST, instance=member)
if form.is_valid():
self.object = form.save()
return HttpResponseRedirect(self.get_success_url())
else:
return self.render_to_response(self.get_context_data(form=form))