changeing ListView get_queryset? pagination in django

Question

Good day everyone. I am having some trouble with the paginator in django. I have in my db all the customers info, so what I want to do is to display that info, but I made a search function in which you clic a letter button, for example you clic A and it will filter all the customers that their last name starts with the letter A, if you clic B , it will filter all customers with their last name start with B, and so on. This works correctly, the problem is that I also want to display 10 customers per page, so if I have 20 customers that their last name starts with the letter A, what you will see, will be 10 customers and a bar that says ( <<< page 1 page 2 >>> ) or something like that, and that should be solved with the paginator, I added it, but its not working. I think the problem is that maybe my get function is rewriting the get_query function from ListView perhaps? I tryed different things but I'm not sure. Here is my code in views:

class ExpedientView(ListView):
    queryset = Portfolio.objects.filter(products__isnull=True).order_by('owner__last_name')
    template_name = 'dashboard-admin/portfoliorecords.html'
    paginate_by = 10

    def get(self,request):
        if request.GET['letter'] == '':
            context_object_name = 'portfolios'
            queryset = Portfolio.objects.filter(products__isnull=True).order_by('owner__last_name')
            context = queryset
        else:
            letter = request.GET['letter']
            context_object_name = 'portfolios'
            queryset = Portfolio.objects.filter(products__isnull=True).order_by('owner__last_name').filter(owner__last_name__istartswith=letter)
            context = queryset
        return render(request, 'dashboard-admin/portfoliorecords.html', {'portfolios': context})

the get(self,request) function, works perfectly, however the first part where the paginated_by is not working.

Before I added the get function, and just filtering all the customers, the paginator worked fine, so in the template, the code works properly.

score 1 · Answer 1 · answered May 19 '21 at 18:13

1

If all you need to do is dynamically change the queryset then instead of overriding get (Which calls the appropriate functions in the view, which will perform all pagination tasks, etc.) you should be overriding get_queryset:

class ExpedientView(ListView):
    queryset = Portfolio.objects.filter(products__isnull=True)
    template_name = 'dashboard-admin/portfoliorecords.html'
    paginate_by = 10
    ordering = 'owner__last_name' # Put the ordering here instead of specifying it in the queryset

    def get_queryset(self):
        queryset = super().get_queryset()
        letter = self.request.GET.get('letter')
        if letter:
            queryset = queryset.filter(owner__last_name__istartswith=letter)
        return queryset

answered May 19 '21 at 18:13

Abdul Aziz Barkat

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I see, instead of changing the get function from the original ListView class, it was easier putting everything in the get_queryset. – add May 20 '21 at 15:55
This worked well. However another problem appeared once this worked lol. What I'm doing on the template, is sending the info by GET method, like this:

However, the paginator works, but when you change the page, lets say change to page 2, the url instead of being mypage.com/expediente?letter=A, it changes to mypage.com/expediente?page=2 and displays all the customers of the second page (doesn't take the filter due to there is no variable letter=A ) – add May 20 '21 at 16:00
@add that is a different question, although easily solved, infact you will find some duplicates too on SO for example see this one: https://stackoverflow.com/questions/2047622/how-to-paginate-django-with-other-get-variables – Abdul Aziz Barkat May 20 '21 at 16:17

score 1 · Accepted Answer · answered May 19 '21 at 18:14

You have to modify the def get_queryset(self) method not the def get(self, request) method

Remove the def get(self, request) method and the below code.

def get_queryset(self):
    queryset = Portfolio.objects.filter(products__isnull=True).order_by('owner__last_name')
    letter = request.GET.get('letter', None)
    if letter:
        queryset.filter(owner__last_name__istartswith=letter)
    return queryset

changeing ListView get_queryset? pagination in django

2 Answers2