I have made a form to filter ListView
class SingleNewsView(ListView):
model = News
form_class = SearchForm
template_name = "single_news.html"
def get(self, request, pk, **kwargs):
self.pk = pk
pub_from = request.GET['pub_date_from']
pub_to = request.GET['pub_date_to']
return super(SingleNewsView,self).get(request,pk, **kwargs)
My form fields are pub_date_from and pub_date_to. When I run the site it says:
MultiValueDictKeyError .
I don't know what's going on. When I remove the two line of getting pub_from and pub_to the site works fine. I want these two values to filter the queryset.
On first request there is no form data submitted so request.GET would not have any data. So doing request.GET['pub_date_from'] will fail. You shall use .get() method
pub_from = request.GET.get('pub_date_from')
pub_to = request.GET.get('pub_date_to')
If these keys are not in the dict, will return None. So handle the such cases appropriately in your code.
Also, if you want to filter objects for ListView add get_queryset() method to return filtered queryset as explained here Dynamic filtering
Related
I have a Model with a lot of entries, so I'm using django-filters to filter the model, I initially load an empty table and from there I use the filter to view the items.
Everything works fine, the page loads initially with no entry, after I filter, django shows the correct items.
The Url gets a parameter: /retetabloc/?acordcadru=532(532 is the filter) but when I try to update an entry, the filter resets(the parameter is still in the URL) and the whole db is loaded.
I don't quite understand how to pass the filter parameter to the RetetaBlocUpdate, so that after the update is done it returns to the filtered items like in the ListView.
views.py
class RetetaBlocListview(LoginRequiredMixin, CoreListView):
model = RetetaBloc
def get_queryset(self, *args, **kwargs):
pdb.set_trace()
acordcadru = self.request.GET.get("acordcadru")
queryset = RetetaBloc.objects.filter(acordcadru=acordcadru)
return queryset
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['filter'] = RetetaBlocFilter(self.request.GET, queryset=self.get_queryset())
pdb.set_trace()
return context
class RetetaBlocUpdate(LoginRequiredMixin, AjaxUpdateView):
model = RetetaBloc
form_class = RetetaBlocForm
Thank you.
If you'd like filters to be remembered you could add them to a session variable instead. That way filters would be recalled even if they didn't go back directly from the update page (and you'd wouldn't have redundant URL querystring on pages where they weren't needed).
Something like:
def get_queryset(self, *args, **kwargs):
pdb.set_trace()
#check for new filter in URL first
acordcadru = self.request.GET.get("acordcadru")
#if nothing check for session variable
if not acordcadru:
acordcadru = self.request.session.get('acordcadru')
#if something in URL querystring, set it in session variable
else:
self.request.session['acordcadru'] = acordcadru
queryset = RetetaBloc.objects.filter(acordcadru=acordcadru)
return queryset
I am currently doing a project which requires pagination. A list of Images is provided to the user and whether they were Favorited or not by user.
Favorited Images are kept in a separate table.
In order to provide a list of images and ones that were Favorited by the user an annotate.
def _get_queryset(self, request):
user_favorited = DjImagingImagefavorites.objects.filter(ifv_img_recordid__exact=OuterRef('pk'), ifv_user_id__exact=request.user.profile)
queryset = DjImagingImage.objects.all().annotate(favorited=Exists(user_favorited))
return queryset
Then in the list function
def list(self, request):
images = self._get_queryset(request)
page = self.paginate_queryset(images) #Breaks here
The Query then throws an error.
]Cannot use an aggregate or a subquery in an expression used for the group by list of a GROUP BY clause.
Due to an oddities of how the paginate function performs the count and constructs an illegal sql statement.
Question is - Is their a better way about going to do this or should this work perfectly as I thought it should have?
A solution that I found works is coded below
def list(self, request):
images = self._get_queryset(request)
#page = self.paginate_queryset(images)
return self.paginate(images)
I create a wrapper called paginate
def paginate(self, queryset):
"""Calculate paginated QuerySet and wrap in a Response.
Args:
queryset - the queryset to be paginated
"""
page = self.paginate_queryset(queryset)
if page is not None:
serializer = self.get_serializer(page, many=True)
return self.get_paginated_response(serializer.data)
serializer = self.get_serializer(queryset, many=True)
return Response(serializer.data)
For those who are wondering the queryset I am constructing
def get_queryset(self):
"""Return the modified/prepared master QuerySet.
Returns:
QuerySet<DjImagingImage>: The modified master QuerySet
"""
return DjImagingImage.objects.annotate(
mine=FilteredRelation('djimaginguserspecifics',condition=Q(djimaginguserspecifics__usp_emp_employeeid=self.request.user.profile)),
usp_favorite=F('mine__usp_favorite'),
usp_inhistory=F('mine__usp_inhistory'),
usp_emp_employeeid=F('mine__usp_emp_employeeid'),
usp_lastviewed=F('mine__usp_lastviewed'),
comment_count=Count('djimagingimagecomment'))
I am able to render class based view generic ListView template using parameter hard coded in views.py.
class ResourceSearchView(generic.ListView):
model = creations
context_object_name = 'reviews'
template_name = 'reviews.html'
query = 'theory'
# def get(self, request):
# if request.GET.get('q'):
# query = request.GET.get('q')
# print(query)
queryset = creations.objects.filter(narrative__contains=query).order_by('-post_date')
However, when parameter is sent via form by GET method (below),
class ResourceSearchView(generic.ListView):
model = creations
context_object_name = 'reviews'
template_name = 'reviews.html'
query = 'theory'
def get(self, request):
if request.GET.get('q'):
query = request.GET.get('q')
print(query)
queryset = creations.objects.filter(narrative__contains=query).order_by('-post_date')
I receive this error
The view creations.views.ResourceSearchView didn't return an
HttpResponse object. It returned None instead.
Note that the parameter name q and associated value is being retrieved successfully (confirmed using print(query)).
So with CBV in Django, you have to return some kind of valid response that the interpreter can use to perform an actual HTTP action. Your GET method isn't returning anything and that's what is making Django angry. You can render a template or redirect the user to a view that renders a template but you must do something. One common pattern in CBV is to do something like:
return super().get(request, *args, **kwargs)
...which continues up the chain of method calls that ultimately renders a template or otherwise processes the response. You could also call render_to_response() directly yourself or if you're moving on from that view, redirect the user to get_success_url or similar.
Have a look here (http://ccbv.co.uk) for an easy-to-read layout of all the current Django CBVs and which methods / variables they support.
Thanks for the responses. Here is one solution.
class ResourceSearchView(generic.ListView):
model = creations
context_object_name = 'reviews'
template_name = 'reviews.html'
def get_queryset(self):
query = self.request.GET.get('q')
queryset = creations.objects.filter(narrative__contains=query).order_by('-post_date')
return queryset
I have researched this issue for a couple of days and can't seem to find what I'm looking for exactly. I have searched ModelChoiceField as well as ChoiceField on StackOverflow as well as Google and there are many variations of my question but nothing exactly. In a nutshell, I am trying to use a Class Based FormView and then capture the user selection and pass it to a Class Based ListView. Here is my code.
Forms.Py
class BookByStatus(forms.Form):
dropdown = forms.ChoiceField(choices=[],required=False)
def __init__(self, user, *args, **kwargs):
super(BookByStatus, self).__init__(*args, **kwargs)
self.fields['dropdown'].widget.attrs['class'] = 'choices1'
self.fields['dropdown'].empty_label = ''
self.fields['dropdown'].choices =
Book.objects.values_list("author","author").distinct("Publisher")
The code above works fine, and shows me the output I'm looking for on my view. No issues there....Then I have my FormView...
class BookByStatusView(LoginRequiredMixin,FormView):
model = Book
form_class = BookByStatus
template_name = 'xyz123/publisher.html'
success_url = reverse_lazy('Book:book_by_list',kwargs=
{'dropdown':'dropdown'})
def get_form_kwargs(self):
kwargs = super(BookByStatusView, self).get_form_kwargs()
kwargs['user'] = self.request.user
return kwargs
def form_valid(self, form):
self.request.POST['dropdown']
BookByStatusView = form.cleaned_data['dropdown']
return super(BookByStatusView, self).form_valid(form)
The code above works fine, but takes me to the ListView below which I can't seem to pass the dropdown value to....I've tried several different iterations of get_form_kwargs as well as changed my form to ModelChoiceField, but still can't seem to understand how to get a queryset based on the input from the user...
And finally the ListView...
class BookByStatusListView(LoginRequiredMixin,ListView):
model = Book
form_class = BookByStatus
context_object_name = 'book_list'
template_name = 'xyz123/book_by_status_list.html'
paginate_by = 15
def get_queryset(self, *kwargs):
form = self.form_class(self.request.GET)
dropdown = self.kwargs.get('dropdown', None)
if form.is_valid():
return Book.objects.filter(dropdown__icontains=form.
cleaned_data['dropdown'])
return Book.objects.all()
I'm trying to take the dropdown input from the FormView and then pass it to a list view using two separate views. I need to pass the value from the FormView to the ListView. I'm clear on how to get the data in the FormView in the ChoiceField, and how to display a ListView, but I can't seem to figure out how to pass the dropdown data from the FormView to the ListView. I can get the ListView to work, but only with the full queryset, not with a filtered one.
Here's the book model....
class Book(models.Model):
Author CHOICES = (
("New","New"),
("Old","Old"),
)
Author = models.CharField(choices=Author_CHOICES,max_length=10)
Here's the URL...
url(r'^book_by_list/(?
P<dropdown>\w+)/$',views.BookByStatusListView.as_view(),
name='book_by_list'),
Thanks in advance for any suggestions!
Updated Approach...Using request.session. My prior approach would not let me pass the value from the one view to the other, no matter how many get_context_data or get_form_kwargs combinations I tried. Based on the input I received, I began exploring the request.session approach and I've gotten much further. One last piece remains, getting the request.session value in my LISTVIEW so I can filter my querysets accordingly.
class BookByStatusView(LoginRequiredMixin,FormView):
model = Book
form_class = BookByStatus
template_name = 'xyz123/publisher.html'
success_url = reverse_lazy('Book:book_by_list')
def form_valid(self, form):
self.request.session['dropdown'] = form.cleaned_data['dropdown']
return super(BookByStatusView, self).form_valid(form)
def get_form_kwargs(self):
kwargs = super(BookByStatusView, self).get_form_kwargs()
kwargs['user'] = self.request.user
return kwargs
And in my html template, I leverage the request.session value as...
{{ request.session.dropdown }}
And I reverted the URL back to..
url(r'^book_by_list/$,views.BookByStatusListView.as_view(),
name='book_by_list'),
The last remaining piece is to figure out how to leverage the LISTVIEW with this approach.
My current Listview:
class BookByStatusListView(LoginRequiredMixin,ListView):
model = Book
form_class = BookByStatus
context_object_name = 'book_list'
template_name = 'xyz123/book_by_status_list.html'
paginate_by = 15
def get_queryset(self):
queryset = Book.objects.none()
dropdown = self.request.session.get('dropdown')
if dropdown == 'New':
queryset = Book.objects.all()
elif dropdown == 'Old':
queryset = Book.objects.none()
return queryset
I can't seem to figure out how to pass the dropdown value correctly to the ListView so the queryset is displayed properly. Based on my testing, I don't appear to be capturing dropdown properly in the get_queryset function. Any ideas?
I figured it out. I updated the get_queryset with the proper syntax. Thanks for all of the help to nudge me in the right direction. Last questions..is this the best way to pass a value from one view to another? Is there a better way to do this? Are there any concerns with this approach?
This doesn't work, because redirect creates a new request/response and data from previous are lost. If I understand what you want correctly, one of the options would be to save the drop-down value to session in BookByStatusView and then retrieve it in BookByStatusListView.
You save to session with:
request.session['dropdown_value'] = form.cleaned_data['dropdown']
and retrieve with:
dropdown_value = request.GET.get('dropdown_value')
Here is How to use session part of Django documentation.
EDIT: You can also pass the value as an url parameter like this:
author = 'michael cricthon'
title = 'kongo'
year = [1999, 2000, 2001]
type = ['electronic', 'print', 'hardcover', 'softcover']
params = '?author={}&title={}&&year={}&type={}'.format(
urllib.parse.quote_plus(author),
urllib.parse.quote_plus(title),
','.join(year),
','.join(type))
return HttpResponseRedirect(reverse('search') + params)
The link would look like this:
../search/?author=michael+crichton&title=kongo&year=1999,2000,2001&type=electronic,print,hardcover,softcover
You get parameters with
author = request.GET.get('author')
title = request.GET.get('title')
... etc.
I have a model form that contains among other things a dropdown list of pupils (ModelMultipleChoiceField), which is initially empty but when a user selects a teacher, I get the list of pupils registered for this teacher via ajax request.
self.fields['pupil'] = forms.ModelMultipleChoiceField(queryset=Pupil.objects.none(),)
Everything works till the validation. Since initially queryset points to none, when a form is submitted it is returned with an error "It is invalid choice".
I can pass the entire set of pupils to the pupil field and then make it empty via jQuery but that looks ugly. What is the right way of doing it?
You can do it as follows. In this case first we render the form with empty queryset after you loading the choices with ajax. you will submit data with a post request. when we receive the POST request we are sending full queryset to the form.
In above case you explained the queryset is empty so you have got validation error as invalid choice. But, in this case we have full queryset so, it will work perfectly.
views.py
def sample_view(request):
if request.method == 'POST':
queryset = Pupil.objects.all()
form = SampleForm(request.POST, queryset=queryset)
# your code goes here
else:
queryset = Pupil.objects.none()
form = SampleForm(queryset=queryset)
# your code goes here
forms.py
class SampleForm(forms.ModelForm):
def __init__(self, *args, *kwargs):
queryset = kwargs.pop('queryset', None)
super(SampleForm, self).__init__(*args, **kwargs)
self.fields['pupil'] = forms.ModelMultipleChoiceField(queryset=queryset)
# your code